And, in a comment with a bit more substance: that paper’s held up really well over time. I guess there’s a damn good reason it was published in Science. The existence of this paper is also good to use against the folks who talk about “global cooling” (yes, I know there’s another RC thread devoted just to that topic!).
I’d also love to have the “problem” of one of my better papers having “only” 71 cites :)
Wally has always been the king of the back-of-the-envelope calculation. This is just one example, and shows how he developed a simple model of CO2 and warming that got within 15% of what actually occurred over 35 years.
A note on early predictions of CO2-induced warming: the New York Times published an editorial on March 24, 1953, entitled “How Industry May Change Climate.” I have a PDF of it, which begins “The amount of carbon dioxide in the air will double by the year 2080 and raise the temperature an average of at least 4 per cent…” The editorial also mentions a recent paper presented by Gilbert Plass at AGU, which I haven’t looked up.
So the potential effects of CO2 on climate have been appreciated for a long, long time.
[Response: Interesting. Not to be picky about a 50 year old newspaper article but... I wonder what 4% temperature increase is supposed to mean, though. They can't mean 4% of 288 K, which would be 11 °C! 4% of 15K. They could mean 4% of 15 C, which is about 0.6. Of course, they were probably thinking F, not C, so perhaps they mean 4% of 59, or 2 F? --eric]
[Response: Surely the author meant degrees (F or C is the question). For some reason non-scientists often confuse this - at least a dozen times in the last couple of years I've heard people talk about limiting global warming to 2%. -stefan]
Stefan wrote: “… warming has been proceeding almost exactly as predicted for at least 35 years now …”
Too bad that other things have not been proceeding exactly as predicted:
* In 1952 — fifty years ago — the Paley Commission reported to President Truman that, “Efforts made to date to harness solar energy economically are infinitesimal. It’s time for aggressive research in the whole field of solar energy — an effort in which the U.S. could make an immense contribution to the welfare of the whole world.” The report concluded that solar could play a greater role in energy production than could nuclear power, and that an aggressive effort could heat 13 million homes and offices by 1975.
* One year before that date, in 1974, even the Atomic Energy Commission admitted that by 2000, solar could provide 30% of the nation’s energy needs.
* In 1972, the American Institute of Architects published its study called: “A Nation of Energy-Efficient Buildings by 1990.” Their study concluded that readily available energy conservation measures installed in old and new buildings would offer an energy supply greater than what we could get from the Alaskan North Slope, or domestic oil production in the continental U.S., or an overly optimistic prediction of nuclear energy output.
Thanks very much for posting this. I normally try to stay aware of such milestones and anniversaries, but this one completely slipped by me.
This raises an issue that I think will increasingly become a sticking point in humanity’s response to this situation: When can we fairly say that we knew with reasonable certainty that climate change was real and that it was largely human caused? I do NOT want to bring up here the arguments about which country or group of countries (i.e. the OECD) is responsible for how much of our predicament, although that’s largely the context in which this question is asked.
Putting the political aspect aside, I would really like to hear the opinions of the RC regulars, both real scientists and the scientist wannabes (like me), on what date you would pick on a time line and say, “by this point we knew about the A in AGW and there was very little doubt, even if we had a lot of uncertainty about the amount of warming and interactions between various parts of the environment, and we should have started to take action to reduce our emissions”.
I know about the report to LBJ from the Presidential Science Advisory Committee in 1965 (and its Appendix Y4) and the 1958 booklet from the NAS that talked about CO2 and water vapor being greenhouse gases, but it’s never been clear to me exactly when it would be reasonable to say that the evidence was not just strong enough but also widely accepted enough by scientists that the rest of us should have taken notice and done something other than buy more cars and bigger houses.
[Response: I like to ponder what must have been going through the minds of some of these guys as they were looking at the results of their calculations and model outputs and getting a first glimpse of what was going on.--Jim]
I am curious about the apparent lack of warming observed over the 20th century for North America. I wonder if perhaps the increase in ‘dust’ from Asia that was occurring just as the ‘dust’ generated in North America could perhaps be responsible.
Anyone have any idea?
[Response: Hmm. I just got back from central British Columbia, which has warmed about 3 C in the last 50 years... Last time I checked, BC was in North America.--eric]
I would really like to hear the opinions of the RC regulars, both real scientists and the scientist wannabes (like me), on what date you would pick on a time line and say, “by this point we knew about the A in AGW and there was very little doubt, even if we had a lot of uncertainty about the amount of warming and interactions between various parts of the environment, and we should have started to take action to reduce our emissions”.
As a scientist-wish-I-were, I’d go with the answer provided by this post, and seemingly backed up with evidence:
Nevertheless, the basic fact that rising CO2 would cause a “pronounced global warming”, as Broecker put it, was well understood in the 1970s. In a 1979 TV interview, Steve Schneider rightly described this as a consensus amongst experts, with controversy remaining about the exact magnitude and effects.
[Side comment: Excellent post. Historical perspective is an important and often overlooked factor in "the debate."]
Our understanding in 1979 may not by itself have implied a call to action at that point, but we’d already suffered through the 1973 oil embargo, knew that U.S. strategic and economic fortunes were tied to a resource we could not necessarily control, knew of other reasons to switch (pollution, ultimate limits to fossil fuel availability, etc.), and knew that other technologies were seemingly within our grasp.
Imagine if we’d started taking action in 1979, where we’d be environmentally, climatically, economically and strategically. Imagine how small the expense (which is the denier’s sticking point) would have been if the issue had been approached gradually but continuously since 1979.
Heck, we might never have fought two wars in the Persian Gulf.
Which leads to another side point. Why haven’t we developed and implemented acceptable solar energy solutions? There are three sources of power on this planet; nuclear, tidal, and solar. 99.99% of all power we see on earth (plants growing, animals moving, winds and waves moving, light and heat) are a result of solar energy. Even fossil fuels are, in fact, solar energy.
So if the sun is in effect the source of almost all power on the planet, and nature has been able to easily transform it into wind, waves, life, movement, and hydrocarbons on a daily basis, why are we so crippled and incompetent in extracting what we need from it?
@7 Lou: When did we know with reasonable certainty that AGW was real? What you mean, “we”? Wally and Steve Schneider and lots of others knew it by the late 1970s, but many scientists and still more non-scientists found lots of valid reason for doubt. I think you can’t pick a better date than 2001, when the IPCC officially announced that there was a “discernible” human effect on climate. At that point “we” included the overwhelming majority of experts and the official consensus of most of the world’s governments. At any time before that, you could say there were defensible reasons for doubt.
Another possible date would be 1988, when the international Toronto conference of experts called for strict, specific limits on greenhouse gas emissions. This represented a consensus (incomplete) of scientists that there was reasonable certainty that AGW was, if not beyond doubt, at least enough of a risk to warrant real action.
FWIW, I personally became convinced in the late ’90s. The last straw was evidence that GCM’s had correctly reproduced the very different conditions of ice-age tropical ocean temperature; I suppose everyone has their own personal last-straw. Bore-hole demonstrations of 20th century warming also played a role in convincing me. Although in all science,conviction should never mean more than, say, 95% sure… there’s always a remote possibility of being wrong.
[Response: Scientific consensus was already strong at the Villach conference in 1985, convened by ICSU, WMO and UNEP. Another possible date would be 1990, when in December the German parliament unanimously voted to reduce CO2-emissions by 25% by the year 2005, following a detailed parliamentary inquiry into the issue that was started in 1987. I think if you get parliamentarians of one of the major industrial nations of the world unite across party lines to back action, the evidence must have been very strong to anyone who cared to properly look at the issue. The latest possible date you could name in my view is the Rio Earth summit of 1992, where the nations of the world decided to stabilise greenhouse gas concentrations in the atmosphere and the UNFCCC was born. -stefan]
oops, my bad, “discernible” was from the 1995 IPCC report (another milestone). The 2001 report more definitely declared that “most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations” where “likely” falls only a little short of reasonable certainty.
Good article. I recall Richard Alley in his book “Two Mile Time Machine” mentioning that if you’re a climate scientist, and you think you have a good idea, chances are Broecker already got to it first. He has done extraordinary work and this paper is no exception.
In response to John Reisman (14), Arrhenius was not interested in anthropogenic global warming. He did do the first quantitative outlook of the effects of CO2 changes on global temperature (of which he got very lucky in being close to modern estimates), but his target was largely to examine the coming and going of ice ages.
If you want to go back and extend the “birthday of global warming” Callendar is probably the first person to look at.
Thanks Chris, I seem to recall something about Arrhenius saying if humans increase CO2 it would be great because we don’t want to go into another ice age. It might have been from Spencers work, but I will have to dig around.
Yes, Callendar was on top of this. I think as early as 1924 or 26?
#7 Lou Grinzo. For me, the A-part of GW became evident a bit after 1995 report, probably 1997/8 winter after checking some things in the report from the original articles in the university chemistry library. C13/14 uptake by plants produced some confusion afterwards, but this was cleared soon after, 1999?
Towards the end, I include an image of a 1953 Popular Mechanics “sidebar” squib on global warming sourced to Gilbert Plass–a scientific correspondent of Callendar’s (as was Keeling.) I haven’t read the letters beyond a few excerpts quoted by Fleming, but I’ve the idea that Callendar was a bit of a long-distance mentor–to Plass especially.
There’s also a lot about Broecker in this “review” of “Fixing Climate,” which includes a lot of Broecker biography:
A terrific review and reminder, both the post and the linked references, thank you. The situation was already sketched out in the 60′s and 70′s, becoming increasingly clear ever since. Making the world’s (mostly non-) reaction all the more tragic, in the sense of a horrific outcome due to ineradicable human flaws.
There is still time to make the future better than it would be without recognition and action, though probably not time to avoid many heartbreaking losses.
Hmmm. Stefan, at the top of your post you list the Broecker paper as “Are We on the Brink of a Pronounced Global Warming?”
But Science (and your “References” section at the end of the post) give the full title as “Climatic Change: Are We on the Brink of a Pronounced Global Warming?”
If Broecker’s original title included the “Climatic Change” part, then it’s kind of remarkable that this foundational paper that first introduced the term “global warming” also exemplifies the tension between the use of that term versus the use of “climate change” … in its very title.
I don’t think much could be done until the theoretical framework was coupled with observed temperature rise. That didn’t start until the 80s, so the first real opportunity was 1988 – Jim Hansen’s congressional testimony. That was when everything kicked off – formation of the IPCC, Thatcher forming the CRU the year after…
That was when we should have made global warming a non-event.
On the question of when did “we” collectively have enough evidence to know a response was required: I’d point to the Rio Earth Summit in 1992. The nations of the world agreed to create the Framework Convention on Climate Change (UNFCCC), which collectively acknowledged the evidence and the need for a response. This framework treaty came into force in 1994, with near universal support worldwide, including the U.S., Europe, China, Russia, India, basically everybody:
The framework Convention is a legally binding treaty, but it simply states that we all see there is a problem, and does not tackle how to go about solving it. That was left for the 1997 Kyoto Accord, which was a Protocol to the Framework Convention. The UNFCCC set up the annual meetings known as “Conference of the Parties” or COP. We’ve kept holding those, recently completing COP-15, and are working up toward COP-16 in Cancun, Mexico this coming December.
The Kyoto Protocol did pass its own thresholds to come into force as an international agreement (>=55 countries totaling at least 55% of emissions), but it was vitiated by the refusal of the U.S. Senate to ratify the treaty, highlighted in the July 1997 Byrd-Hagen Resolution: http://www.nationalcenter.org/KyotoSenate.html
The Kyoto Protocol is still in force today, for those Parties (countries) who ratified it. It governs the period from 2008-2012 for Annex I parties, who are obliged to meet whatever target they set for themselves in the course of the negotiations, stated as a % reduction in emissions from a 1990 baseline.
Some parts of Europe are actually on track to meet their Kyoto commitments. Canada, which ratified the treaty, has admitted this now far beyond the realm of possibility for us, as we’re perhaps 25 or 30% over our 1990 levels and have very little policy in place yet to achieve any cuts or even to slow the growth of emissions. “Oh, well…” (national shrug?)
So by the reckoning that 1992 was the year the world community acknowledged the problem, we’re now in year 18 of dithering over whether to do anything to slow and someday start cutting emissions.
This could at least remove one of the main stated objections behind Byrd-Hagel in the U.S., though other objections such as “devastate the economy”/ “it’s a tax” may remain key moves in U.S. inactivists’ playbook.
One part makes no sense. You state that “based on this logarithmic relationship (still valid today) Broecker assumes a climate sensitivity of 0.3ºC warming for each 10% increase in CO2 concentration, which amounts to 2.2ºC warming for CO2 doubling.” I certainly understand the logarithmic relationship – that’s straight 2nd law stuff. But then you go on to linearly extrapolate the temperature. This doesn’t make sense.
Assuming the first 10% increase in CO2 leads to a 0.3C warming, then ln(10) = 2.303. 0.3 and 2.3 should be proportional – the ratio is 0.13.
Doubling the CO2 concentration requires taking ln(100), or 4.6. Employing the same ratio yields a temperature increase of 0.6 C, not 2.2.
I have never understood this. From the second law, chemical activity is proportional to the logarithm of the concentration, and yet the temperature increase is always calculated linearly, as in your example. On a logarithmic scale, the doubling of CO2 concentrations is, frankly, not especially significant.
[Response: The logarithmic impact of CO2 is not related to the 2nd Law in any direct way. It is simply a function of the climate state and the atmospheric composition we have. The forcing for increases in CO2 is approximated by ~ 5.35*log(CO2/CO2_orig) in W/m2 (Myhre et al, 1998), and the planet responds (to first order) linearly to changes in the forcing. The forcing for a 10% increase in CO2 is 5.35*log(1.1) = 0.5 W/m2, and so if that gave 0.3 deg C, you would expect 3.7*0.3/0.5 =2.2 deg C for when you get to 2xCO2. Hope that is clearer. - gavin]
Actually back in early 1979 I would have been writing up my final project report for my diploma at a further education college here in the UK. It was titled ‘Sun Tracking for Solar Cells and Parabolic Reflectors’.
I remember making the mechanism out of Meccano and burning out the only transistors I had trying to drive the motors.
I still have the (rather good) report, which has a hand drawn graph of the spectrum of sunlight reaching the ground, with the visible band clearly marked. I’m sure I probably copied the graph out of a book.
Dan King – I think you are getting confused with percentages. It’s not log of 10 or 100 that you need to take, it’s log of 1.1 and 2 – log 2 is a bit more than 7 times log 1.1, so the increase in temperature for a doubling of CO2 is a bit more than 7 times the warming you get from a 10% increase in CO2.
Sorry, but that still makes no sense. The absorption and emission of IR radiation by CO2 is a chemical process, and MUST be related to the second law. There is no escaping that.
I don’t know what “forcing” means, so I don’t really understand. But whatever it is, I can’t believe it turns a logarithmic process back into a linear one.
[Response: Sorry, but nothing is turning a logarithmic process into a linear one. Calculating the difference that increasing CO2 makes on the radiation at the top of the atmosphere (i.e. the forcing) depends logarithmically on CO2 concentrations. The planet to first approximation reacts linearly to whatever forcing is imposed (whether it is from the sun or from a volcano or from CO2). Two separate processes. - gavin]
10% doesn’t imply log(10). It implies log(1.1), since a 10% increase of 1 (being the “present” level) is 1.1. And, log(1.1) (using natural log) is 0.0953.
Meanwhile, log(2) is 0.693. The ratio log(2)/log(1.1) is 7.27, so we need 7.27 increases of 10% (compounded) to achieve a doubling. If each 10% increase raises temperature by 0.3 deg.C, then 7.27 of them would raise temperature by 2.2 deg.C.
(Please note with this and the other links I posted above that they’re in a DropBox account and sometimes won’t load a PDF correctly. If that happens, just hit refresh and try again. It’s not clear to me what issue DB has with PDFs, but it’s usually not a significant issue.)
Dan King: You obviously made a basic error, because if you are right that “Doubling the CO2 concentration … yields a temperature increase of 0.6 C” then clearly a rise of 0.6 is the same as two rises of 0.3 each. And if 0.3 is produced by a 10% increase, then two 10% increases are plainly not the same as a doubling.
Thank you for your patience, and I admit I’m a novice to this. But I do know my thermodynamics. Taking your statement as correct – that “forcing”, whatever it is, is proportional to the log(CO2), then increasing the CO2 concentration from 1.1x to 2x should result in multiplying the temperature by a factor of 1.8. It doesn’t matter how many processes are involved: 1, 10, 135. There is no way that anything can depend exponentially on the concentration, which is what the ratio log(2)/log(1.1) implies.
OK – so I’ll shut up and leave you folks alone. Thanks again.
[Response: Sorry again, but just work through the maths: Temp change ~= sensitivity * forcing. (T = a * F). For a 10% change in CO2, the temperature change is posited to be 0.3 deg C, thus sensitivity a=0.3/(5.35*log(1.1)). For a doubling of CO2, the temperature change is thus: T = 0.3/(5.35*log(1.1)) * 5.35*log(2) = 0.3*log(2)/log(1.1) = 2.2 deg C. - gavin]
My wife was a researcher on James Burke’s documentary “After the Warming”, which came out in 1990. It was already abundantly clear then that warming was going to happen, and that it was largely due to anthropogenic causes.
We watched it again recently, and it is scary how accurate JB’s predictions were – although things that he said would only start happening in the 2020s or 2030s are already happening now.
Every time I hear someone declare that climate science is an “immature” science, or that we need to wait for more evidence, I want to sit them down in front of “After the Warming”, and ask how much longer we need to wait.
Dan King, I think you are confusing the relationship between CO2 concentration and radiative forcing, and the relationship between global temperature and radiative forcing. The “forcing” by the way is just a measure of how the net radiative balance of the planet is perturbed by a change in solar irradiance,greenhouse gases, etc. That alone doesn’t tell you anything about the temperature change realized at the surface, since this also depends on how sensitive the system is to that forcing, which depends on feedbacks.
For a change in CO2 concentration, the forcing is given as RF_CO2=k*ln[CO2(t)/CO2(0)] where k ~ 5.35 W m**-2 and CO2(t), CO2(0) represent the final and initial concentration. Thus, a 10% change in CO2 (e.g., from 300 ppm to 330 ppm) corresponds to a forcing of 5.35*ln(1.1)=0.5 W m**-2. A doubling of CO2 would be RF_CO2=5.35*ln(2)=3.7 W m**-2.
The global mean temperature response to the imposed forcing is:
where λ is a sensitivity parameter expressed in degrees C temperature change per unit radiative forcing (whose value is a diagnostic of how strong various feedbacks are, and thus of the climate sensitivity). In the discussion with you, gavin and other commenters have assumed λ to be invariant over the range of climate change we are interested in. A central estimate of λ is ~0.75 degrees C/(W m**-2), so
dT (1.1xCO2)=0.75*5.35*ln(1.1)=0.38 C
dT (1.5xCO2)=0.75*5.35*ln(1.5)=1.6 C
dT (2xCO2)=0.75*5.35*ln(2)=2.8 C
note that previous comments are using λ closer to 0.59 degrees C/(W m**-2) but the implications for this discussion are the same.
It follows from this that the logarithmic dependence of the outgoing longwave radiation (which by the way, has to do the the exponential decay of the absorption coefficient away from the center of the absorption line) can still lead to significant temperature changes, particularly since water vapor enhances the value of λ and smoothes out a plot of the outgoing radiation vs. temperature (making it more linear than T**4). The log dependence though does mean that incremental changes of CO2 produce forcings smaller than the last similar incremental change (e.g., the forcing from 200 to 400 ppm is the same as the forcing from 500 to 1000 ppm, not 500 to 700 ppm). This is fortunate because if it were not the case, then CO2 doubling would be lethal and the Earth would be subject to extreme changes in climate. This is not the case, but it doesn’t mean the Earth is insensitive to change.
In an odd case of cinematic symmetry, two films came out in 1973 with bearing on climate change: “Soylent Green,” and “American Graffiti.” “Soylent Green,” dystopian sci fi set in 2022, with Charlton Heston and Edward G. Robinson (Robinson’s last film), includes this dialogue between them:
How can anything survive in a climate like this?
A heat wave all year long.
A greenhouse effect. Everything is burning up.
“American Graffiti,” set in 1962, is in part a love affair with cars.
I’m so grateful that RealClimate exists. Today I read a news article about global warming on Yahoo (nothing startling in it, just that yes, the world is getting warmer, like we’ve been saying), and after reading the comments, remembered why I never read the comments. (It was this one, if you want to get a taste of what I mean: http://news.yahoo.com/s/ap/20100728/ap_on_sc/us_sci_state_of_the_climate) Post after post after post decrying that global warming exists, that it’s caused by humans, that it’s even a bad thing. Ignorant, blind excuses for reasoning are offered up as if they’re fact, making me wonder if we have any hope at all. After all this time, after the mountains of data, after the lives dedicated to finding the truth, people still look away, still deny its existence. Happy birthday, global warming, you may have the last laugh at our stupid species.
But then … I come here … and I have a flicker of hope. Thank you.
Re #20–Callendar’s initial publication on CO2/climate theory was the paper Lou Grinzo cites, “On The Artificial Production Of Carbon Dioxide. . .” The year was 1938.
You can access the paper via Lou’s link, or if that doesn’t work, Google “pale wiki climate,” which should get you to the collection of “classic global warming science.” There are about 20 papers available there, nicely indexed, so you can pick papers from Fourier 1824 right up to Hanson (IIRC.) I’ve done articles on the first 6, and have one on Plass in process–at least, it’s “in process” whenever I can free up some time to actually work on it.
There is also a discussion of Callendar 1938 in my article, linked at #22 above.
Regarding Soylent Green — spoiler alert to anyone who hasn’t seen it! — what most people remember is the final moments of the film when Charlton Heston’s character discovers that “Soylent Green is people!”, specifically, the ground-up corpses of people who have voluntarily ended their lives by going to one of the public suicide centers.
But the really shocking point in the film is what causes Edward G. Robinson’s character to go to a suicide center: he and a small group of other scientists get their hands on an ocean survey conducted by the Soylent Corporation, which has been harvesting phytoplankton — the last remaining lifeform on Earth other than humans, all other species having been driven to extinction — to make the “food product” Soylent Red.
As they study the Soylent Corporation’s survey, they realize what it shows: that the phytoplankton too is at last dying off, and will shortly become extinct, leaving human beings as the only thing living on Earth — and the only thing left to eat.
Which is what sends Robinson’s character off to the suicide center, to enjoy a chemically-induced euphoria, watch a ten-minute 3D IMAX movie of the long-vanished natural beauties of the Earth, and be “put to sleep”.
The article referenced by Ben in #5 also states: “All this reinforces a theory advanced in 1861 that decreases in carbon dioxide explain the growth and advance of glaciers at various intervals in the earth’s history. Dr. Plass finds the theory plausible“. This refers to the work of Tyndall, who at that time was making the first connections/speculations between atmospheric composition and large scale climate variations. Note also that this NYT writer was on top of this–Plass’ full article on the topic didn’t come out until 1956, where he describes a climate sensitivity of 3.6 to 3.8 deg C. The NYT article was based on a conference presentation which apparently was the basis of Plass’ 1956 paper.
I studied “Environmental Change” – a course on human-induced global warming, basically – under the late Prof. Kenneth Hare at University of Toronto in about 1980. (Talk about a revelation!) I’m pretty sure we were reading scientific papers that pre-dated 1975. I might even still have them in a box someplace.
“The present natural cooling will, however, bottom out during the next decade or so. Once this happens, the CO2 effect will tend to become a significant factor and by the first decade of the next century we may experience global temperatures warmer than any in the last 1000 years.”
“The latter turned out to be correct.”
I’m sorry, but I thought the temperatures of the last decade of the 20th century did not exceed the MWP? Yes?
[Response:No. But this is very definitely off topic. - gavin]
Credit where it’s due, he made a good prediction at a time when it did not seem obvious. This is why I am not a “denialist” (one of the reasons.) If I remember correctly, Steve Schneider at the time was still saying there was not enough evidence to substantiate a prediction (was he transitioning from a “cooler” to a “warmer”?)
In the table, the predicted increase for 2010 1.1C since 1900 (did I read the table correctly?) The observed increase is 0.8C. If you adjust his model to get the correct amount, what does it predict for the next 30 years? Just curious, as there are lots of predictions already out there for the next 30 years, but his has a track record worth building on.
Yes, I remember being taught about the oncoming Ice Age – and trying to imagine New York City being encroached upon by Glaciers, as I learned about Geophysics and Oceanography, in the late 1970′s early 1980′s; so, at least at first, Global Warming was a surpirse – but not at all a hard sell.
I lived in or around Omaha, NE., USA, in the mid 70′s and again in the late 80′s early 90′s; and it was impossible NOT to notice the changing climate. Though it was common to climb out a high window, to unblock the drifted shut door to our house, in 1978; in the later [eriod, the usual precipitation had changed over to mostly freezing rain – with drifted snow becomming very, very rare.
The OED lists a 1952 _San Antonio Express_ usage of the term global warming: “Scientists who are studying global warming trends point out that not a single iceberg was sighted last year south of Parallel 46″ (April 28, 1952: 2, 5).
[Response: Love that dictionary. The OED are actually very keen to have updates to their 'earliest use' cites, so if people can find earlier examples, they should send them along. - gavin]
“The climate feedbacks are obtained based on the constraints of the TOA radiation imbalance and surface temperature measurements of the present climate. In this study, the TOA imbalance value of 0.85 W/m2 is used. Note that this imbalance value has large uncertainties. Based on this value, a positive climate feedback with a feedback coefficient ranging from −1.3 to −1.0 W/m2/K is found. The range of feedback coefficient is determined by climate system memory. The longer the memory, the stronger the positive feedback. The estimated time constant of the climate is large (70~120 years) mainly owing to the deep ocean heat transport, implying that the system may be not in an equilibrium state under the external forcing during the industrial era. For the doubled-CO2 climate (or 3.7 W/m2 forcing), the estimated global warming would be 3.1 K if the current estimate of 0.85 W/m2 TOA net radiative heating could be confirmed. With accurate long-term measurements of TOA radiation, the analysis method suggested by this study provides a great potential in the estimations of middle-range climate sensitivity.”
Now most of the variation of the last 13 decades happens to be nicely explained just by CO2 alone, the other forcings (approximately) canceling each other out. So with quite a simple climate model: http://www.realclimate.org/index.php/archives/2010/03/unforced-variations-3/comment-page-12/#comment-168530
in which the first formula is missing a rgith parenthesis and should read
AE(d) = k(lnCO2(d-1) – lnCO2(1870s)) – GTA(1880s)
just that does quite well but there are clearly unexplained wobbles above and below; the mid 20th century century cooling is one of those wobbles.
So in the second table there is a contribution from the Atlantic Multidecadal Ossicllation (AMO) has a index of internal variability. This helps to explain most of the wobbling, but not all of course. However, the AMO is based on North Atlantic SSTs and so is affected by nonlinear aspects of forcings which changes those SSTs. In particular, some contribution from CO2 leaks in as the forcings due to CO2 is not linearly increasing over the 13 decades. But also whatever changes in aerosol contributions will leak in as well. So the wobbles in the AMO are partly due to those other contributions.
The net of all this is that the AMO, for the linked simple model, explains almost all of the variance not explained by CO2 alone; it is not just an index of internal variability, although I opine, without actually knowing, it is mostly that with some additions or subtractions due to other causes.
A bit OT, but SecularAnimist (52) mentions phytoplankton – I just read today (an AP article: http://www.msnbc.msn.com/id/38451744/ns/us_news-environment/) that phytoplankton numbers have declined by 40% since 1950. The methods included measurements of ocean turbidity, so it’s a proxy measure for a very difficult-to-conduct population survey of phytoplankton species. The method seems to be valid however. May be premature, but the decline is attributed to AGW. Talk about canaries…
How I love to reminisce. As recently as 1982, I was still distracted, listening to my generators instructor talk about how PCBs were no more dangerous than a peanut butter sandwich, and preparing a report on acid rain, soon to be astonished on how the local Edison could lie through their teeth about a study they funded.
Jim Hansen’s congressional testimony was a seminal event that I remember clearly, and when my professional organization, IEEE, printed a cover story in 1999 on global warming in their Spectrum Magazine, I was sure we were on the right path. The last 11 years or so have taken a decidedly unexpected turn.
Climate change was a subject like x population control, racism, or y, one that polite people just didn’t want to talk about.
Propaganda can defy reality, change the world, for a while. But reality always wins by shaking and destroying the foundation that the propaganda was built on. Although we might win a battle or two, we can’t win a war against nature,
A minor point: If US readers follow the link for “Our Threatened Oceans”, they will find a further link for purchasing the book from Amazon UK. You can also get it, at lower cost, from Amazon US and other sources (although Amazon UK has the advantage of availability of Goon Show reissues with your order, providing a bit of much-needed sanity in these difficult times, which may make the trans-oceanic postage worthwhile).
Of course thermo is involved in how the atmosphere interacts with radiation etc, but those are low level details. What we get are the IR forcing (one way to think of it is the average back IR radiation from the sky to the ground -or at fixed global temperature the decrease in IR radiation to space as a function of CO2. Using Gavins formula you get about 4watt/M**2 per doubling. The (near) logarithmic dependence comes from the fact that the absorption line shapes fall off exponentially as the frequency varies from the line centers -so the effective width of the line varies are the LOG of concentration. The change in either the backradiation -or the shielding effect of IR to space as a function of CO2 concentration, is actually a weak effect -roughly a 1% change per doubling. If it weren’t for the fact that our planets biosphere/cryosphere is quite sensitive to small changes in temperature (a 1% change in absolute tempeature is almost 3C) GW wouldn’t be a big deal. But a 1% change in the planets temperature can have a major impact.
I’ve known about GW since the 60′s. I was a voracious reader of astronomy and weather books as a teenager. The basic idea has been known to those with an interest in how the planet functions for quite a long while.
I knew of the possibility of anthropogenic global warming when I was still in high school, around year 9 to year 11 (year 12 aka matriculation for most students, is the last year of school before university, if that’s a help for non-Australian readers). That puts it around 1979 to 1981 for me.
Obviously I couldn’t “know” it was true at the time, for AGW had no track-record with a statistically significant signal, and I was a high-school student, not a seasoned scientist! However, in 1988 there was a greenhouse Conference and workshops for scientists, as well as seminars for the public. By then I knew that CSIRO and many other more famous organisations/universities had their climate scientists stating that global warming was baked in, even if some doubts remained about the magnitude of change in all major climate indicators. The natural conservatism of scientists suggested to me that the bottom line may well be much worse than officially reported.
I suppose I knew about the natural Greenhouse effect (eg Venus) and how it worked in the 70′s, via magazines such as New Scientist, Scientific American (thank G-D it existed), and from Astronomy books, as someone else has mentioned. But 1988 would be not the “Ah hah!” moment, more like the “Oh Nooo!!” moment in disaster movies etc.
These days I feel it is so likely as not worth debating with anyone over the odds. A bet on anthropogenic global cooling, or even just global cooling, for the next 20 years or so would be a suckers bet. I just couldn’t take the money from someone so disabled as that.
This only searches Time Magazine and a few other publications, but results surprise.
Kudos to RealClimate and all of climate science for the persistence of effort. But shouldn’t we also note the passing decades while society has ignored this science? I suspect this is more of a testament to the power of public relations.
Google Search is a tremendously powerful tool for online research. Google engineers devised a way to display search results in a timeline layout. This is a great way of visualizing a search term across time. You will see a list of news stories for the time section you choose. Then you can see your report displayed over days, months or years.
“An easy first search is to enter “Global Warming” or “Climate Change” over a year range and see just how far back the story of global warming goes. I found global warming news stories in 1967, 1968 and 69 and beyond. The timeline display shows a handful of news stories for each year. Each with the top news headlines as a hotspot to click for further information. It was startling to see global warming news stories published so long ago. And alarming to see a 1988 news story with much the same phrasing as global warming news story today. ”
One can see a attitudinal change in media coverage with Time Magazine and others – with the sudden rise of the phrases of other scientists, doubt and skepticism.
It’s interesting to search out the earliest usage of ‘global warming’ but we shouldn’t get too sidetracked by where the precise phrase first appeared. The hypothesis of anthropogenic global warming was first articulated clearly in 1938 in this paper (abstract if PDF doesn’t work) by Callendar. In this paper Callendar,
1) Proposes that CO2 is increasing in the atmosphere and will not only lead to coming global warming, but is already.
2) Discusses measurements of increases in CO2 in the free air. He notes that CO2 is increasing and will continue to do so in the coming century and beyond
3) He discusses the infrared absoprtion by CO2 and water vapor, and is fully aware of the Planck distribution of Earth-like radiation which peaks near 10 um, and is negligible at shorter wavelengths than ~4 um. He is also aware of where CO2 strongly absorbs. He notes on pp. 225, “To return to the absorption by carbon dioxide, the three primary bands given by this gas are at 2.4 to 3.0 um, 4 to 4.6 um, and 13 to 16 um, the latter being much the most important for atmospheric conditions because very little low temperature radiation is carried on the small bands.” He also notes previous measurements noting strong CO2 absorption near 15 um, and further notes that CO2 could absorb away from the primary bands
4) He discusses in length the relationship between CO2 and “sky radiation” (the downwards radiation to the surface). While he seems to not quite understand the primary importance of the top of the atmosphere energy budget, he is well familiar that a quantiative treatment of the effects of CO2 requires consideration of the the vertical thermal structure of the atmosphere, and treats the atmosphere as a number of layers that extend vertically. Callendar notes, “…increase of carbon dioxide causes the radiation to be concentrated from the lowest air layers, whilst the amount from the cold upper layers is still further screened off, the net effect being a small increase in the total sky radiation” which accurately characterizes the fact that the atmsophere becomes brighter in the IR when viewed from the perspective of the surface. Callendar thus understands that one aspect of increasing CO2 is to reduce the height of the “effective radiating level” (from the view of the surface).
5) Callendar notes that the radiative effect of CO2 is stronger in the Arctic due to the absence of water vapor, but incorrectly points out that the actual temperature change realized will be roughly uniform over the globe (he is apparently unaware of the ice-albedo feedback).
6) He doesn’t stop here. Callendar then goes into a detailed account of observed trends in surface temperatures over many locations over the globe, primarily relying on the Smithsonian publication “World Weather records,” and examining about 200 records. He even classifies records by their level of exposure to the urban heat island effect (he doesn’t use this term, but categorizes by small island/ocean/rural, small towns, and large towns). Callendar notes positive temperature anomalies in most records.
7) In this publication Callendar noted that the warming that is observed and that would continue from CO2 could be benefitial, and also that “In any case the return of
the deadly glaciers should be delayed indefinitely.”
This is the earliest most comprehensive, single paper articulating the relationship between CO2, radiative transfer, measurements of CO2, and measurements of temperature and connecting the dots to form the skeleton of what we are worried about over 70 years later. There was certainly earlier efforts which discussed the importance of atmospheric absorption by gases to climate, but such work (like that of Arrhenius) were not concerned with anthropogenic global warming or only speculated that it might be of importance in the deep future, and for that matter did not engage in the observational aspect of CO2-temperature relationships that Callendar attempted. Arrhenius’ 1896 publication has several pages devoted to a translation of previous work by Hogbom noting that CO2 variations were likely quite large in the past, but to Hogbom crustal processes were of much more importance than fossil fuel combustion could be. For the most part, this research, among others before Callendar, was focused on the causes of the glacial-interglacial cycles.
Speculation of anthropogenic warming and geo-enginnering the climate via combustion of fossil fuels is traceable bacj before Callendar, to at least 1899 in this paper by Nils Eckholm. Eckholm recognizes the influence of ‘carbonic acid’ for the climate, and remarks that it is essential for life. He doesn’t quite understand that the rise in CO2 will influence climate over the next few decades to centuries, but the focus has at least shifted to anthropogenic warming and the future– though it is still not until Callendar (1938) to examine this connection in detail. He notes here, “But here we find a remarkable circumstance that has hitherto been unexampled in the history of the earth. This is the influence of Man on climate.”
His conclusing paragraph is,
“In fact, we have seen that the present burning of pit-coal is so
great that in one year it gives back to the atmosphere about 1/1000 of its
present store of carbonic acid. If this continues for some thousand
years it- will undoubtedly cause a very obvious rise of the mean
temperature of the earth. Also Man will no doubt be able to increase
the supply of carbonic acid also by digging of deep fountains pouring
out carbonic acid. Further, it might perhaps be possible for Man to
diminish or regulate the consumption of carbonic acid by protecting the
weathering layers of silicates from the influence of the air and by ruling
the growth of plants according to his wants and purposes. Thus it
seems possible that Man will be able efficaciously to regulate the future
climate of the earth and consequently prevent the arrival of a new Ice
Age. By such means also the deterioration of the climate of the
northern and Arctic regions, depending on the decrease of the obliquity
of the ecliptic, may be counteracted. It is too early to judge of how far
Man might be capable of thus regulating the futnre climate. But
already the view of such a possibility seems to me so grand that I
cannot help thinking that it will afford to Mankind hitherto unforeseen
means of evolution.”
I wrote: “… this foundational paper that first introduced the term ‘global warming’ also exemplifies the tension between the use of that term versus the use of ‘climate change’ … in its very title.”
Secular animist replied:
Global warming causes the climate to change. Seems pretty straightforward to me.
If you look at the discussion of this subject both in the popular press and the scientific literature, people go back and forth between using the terms “global warming” and “climate change.” I don’t think that’s some nefarious plot; I think it’s genuine uncertainty about the tradeoff between simplicity/clarity versus comprehensiveness. Overall, the effect of increased CO2 is to warm the globe but the ultimate impacts of that go beyond just palpable “warmth” to include things like changes in precipitation, ocean circulation, etc.
I just thought it was kind of neat that the (or a) pioneering paper in 1975 that was the first to introduce the term “global warming” apparently also reflects (in its very title) the terminological ambiguity that we continue to experience today. This isn’t a big issue; it’s trivial compared to the substance of the paper. But apparently right from the start even Wally Broecker couldn’t make up his mind whether it’s better to call this phenomenon “climatic change” or “global warming” … so he went with both!
#72–great summary of some of the early “classics” in the field–and a great “pre-response” to Girma’s #74!
One slight clarification–the last block quote is from Ekholm 1901. (The attribution of the pronouns “he” and “his” may be a little unclear to some readers, but Chris means Ekholm.)
For those who like a good slug of biography with their science, I’ve done a web article on Ekholm too, in addition to the one on Callendar linked upthread. If the moderators will indulge me, I’ll link all 6 articles currently up:
J(75): Good summary of the “CC vs. GW” terminology situation.
I find it fascinating and frustrating that the self-professed skeptics seem to get so much mileage out of claiming that “now they’re calling it climate change!” (One somewhat prominent “skeptic” is a local TV weatherman who writes letters to the local paper taking cheap shots at scientists and their work. I’ve seen him use this tired old attack.) If anything, I think CC is far more unsettling than GW, and on my site I was even calling it “climate chaos” for a while, as a way to emphasize the uncertainty involved as well as all the “it’s worse than we thought” discoveries that were popping up in the news. That usage didn’t catch on, despite my efforts and some other people using it; perhaps it’s “too alarmist”.
eric, thanks for your earlier response; I wasn’t aware that central BC had warmed that much recently. Here in Calgary AB (and all of central and southern Alberta) we haven’t warmed much at all in the last 100 years: http://www.abll.ca/charts/Meteorology/Temperature
Ft McMurray (tars sands area) can also be shown on the chart and the warming in more Northern regions is evident.
I am still curious about why I can’t grow a decent vegetable garden even though we are losing our glaciers and ice caps.
Any recommendations on reading about sources of variation at a regional scale?
A large percentage of the populace doesn’t understand the difference between a relative scale, like Celsius or Fahrenheit, and an absolute scale, like Kelvin. In fact, most don’t know what Kelvin (or Rankine, heaven forbid) is. So, I think there might be some merit in framing the amount of change per doubling of CO2 as about 1 percent. It isn’t entirely accurate or precise for a number of reasons, but it sounds plausible to a layman, puts it in the right ballpark, and gives a point from which to build. This side-steps a common sticking point that occurs when people hear that doubling a gas that used to make up 0.0287 percent of our atmosphere, which is imperceptible as far as they are concerned, will have a ~3 degree C (~5.4 degree F) effect, which is quite perceptible within their frame of reference. Using one percent keeps the perceived level of the gas and its effects in the same category of that’s-not-much. It’s a starting point to get someone on to the bunny slope.
Sorry, but there are things which can not be explained very accurately in three easy steps, the average person won’t go beyond three steps, and most of us live in democracies where the average people get to decide what the group does.
I puzzled over why phytoplankton would be in decline because of temperature; they are found in waters warm and cold. Seems an answer could be that there is less overturn in the oceans, and so less nutrients are brought up from the bottom.
So, just thinking, but if the overturn of the oceans is in a general decline, that would have a large effect on the rate of changes at the surface, for temperature, acidity, and others. There would be less buffering in general.
I like to ponder what must have been going through the minds of some of these guys as they were looking at the results of their calculations and model outputs and getting a first glimpse of what was going on.
Someone who wants me to believe me the denial side has a case sent me a link to Rancourt’s latest video. My response: Just because he’s on the left of politics doesn’t exclude the possibility he’s a fruit loop (but leftist anarchists will I’m sure appreciate the assumption that their every pronouncement is authoritative).
The authors are the same for last year’s Science magazine; The Dynamics of Phenotypic Change and the Shrinking Sheep of St. Kilda, Science 24 July 2009, which prompted Gavin to write a follow-on post to “The Sheep Albedo Feedback”, titled “Science at the bleating edge”.
Another “pioneering discussion” maybe necessary to include rodents into the ruminant radiation budget. After all — increasing numbers and size matters… don’t forget the yellow belly which is exposed when sunning.
Wallace Broecker needs defending at http://dotearth.blogs.nytimes.com/2010/07/29/lessons-from-two-important-climate-forecasts/
where a super-denialist has Comment #1. Still waiting for Comment 2 to appear.
Andy Revkin is also celebrating the 35th anniversary/birthday. 1. Brad Smith repeats all of the old long since debunked nonsense stuff that it gets boring to debunk again. I put in a comment that isn’t up yet debunking part of it and then I got bored and pasted. Pastes don’t work there, so I expect to see only part of what I intended to say. Does anybody have a software to get around anti-pasters for Mac OS 10.6?
Comment by Edward Greisch — 29 Jul 2010 @ 11:22 PM
Dear Gentlemen, congratulations to your 35th birthday! The deniers have a new iPhone application that is 5 times more extensive than John Cook’s excellent app.
[Response: Exaggerated. BC controls make sense from a health and climate point of view, so there is nothing wrong in principle. But depending on exactly what you did (how are organic carbon aerosols changed at the same time, the impact of biomass burning) you could get different size net effects. In terms of attribution, BC is something like 20% of the net positive forcing, and so, you'd expect something like that in terms of reducing the global warming signal. (there are issues related to indirect effects, efficacy and time scales that make that a little uncertain though). -gavin]
Pardon my ignorance. Does anyone know whether the kinetic energy of a falling or disintegrating glacier or ice sheet is included in the equations for modeling melting ice? Many millions of tons of ice, elevated a mile or more. Or the energy of the falling water draining through the ice? Do the melting equations include this enormous energy, which will ultimately be heat and contribute to the melting?
A link will be appreciated.
How accurate is the headline, “Controlling Soot Might Quickly Reverse a Century of Global Warming” on wired.com?
A one-shot deal, the devil is in the fine print, like kids’ juice boxes touting “Real Juice!” Once you’ve undone one century of warming you’re fresh out of soot, permanently, so that leaves the remaining upcoming centuries to deal with.
No “Get out of jail free” card on this game board, sadly.
Jim Ryan wrote: “How many more papers will it take to convince the ’sceptics’ of the reality of AGW?”
There will never be enough to counter the many, many “papers” that have convinced them that global warming is a hoax.
You know — the little green & gray “papers” with pictures of dead presidents on them.
Comment by SecularAnimist — 30 Jul 2010 @ 11:04 AM
Thanks Chris Ho-Stuart, from your figures I suppose that there could be 2-4 % extra energy available IF this factor has not been included in the models. Of course that energy is carried away with the melt water, but it is concentrated in the channels where the water flows, as it flows. This makes the fissures wider helps to weaken the structure of the ice. I suppose.
Gavin, a secondary question would be how much of the arctic seaice loss is due to black carbon? I would venture it is significantly more than 20%. For two reasons. Soot above a reflective surface absorbs moe than soot over say forest or ocean. And, soot deposited on snow/ice may absorb solar energy for the entire meltseason rather than the week or two it is resident in the atmosphere. My (not modeled) hunch is that BC has a lot to do with the delta between observed seaice loss and modeled loss.
[Response: That's possible - but not necessarily obviously true. Some work on this in Shindell's recent papers, but note that discussions of 'attribution' when you have cooling and warming factors together can get a little murky (and aren't always consistently described). - gavin]
catman306, there is point on the energy of falling ice OR melting ice which is well worth thinking about. It is different in kind from the energy input from a forcing, such as a greenhouse forcing.
Adding a fixed amount of a greenhouse gas to the atmosphere, or changing the albedo by painting a roof white or clearing a forest, or coating an ice field with a thin layer of black carbon, is not providing a certain fixed amount of energy. All the “forcings”, by definition, work by modulating in some way the continuous flow of energy between the Sun and the Earth and back out to space again.
Their effect, therefore, is ongoing.
Dropping a block of ice, or melting it, takes a fixed amount of energy, which is dissipated once and then is finished with.
Such considerations, therefore, are fundamentally different from the considerations of forcings upon climate. All they can do is work as a kind of “sink” to soak up (or supply) a bit of energy that delays or speeds up the time to equilibrium; they do not affect the state of equilibrium.
The largest “sink”, by far, is the thermal heat sink of the ocean. The consequence of a “forcing” is to set up a new energy balance, and the effect of that forcing will be complete once all the ocean has warmed up to reach the new equilibrium. This is often called “warming in the pipeline”.
Think of it this way. Suppose we have a forcing of 1 W/m^2. (This is what you get from about a 20% increase in CO2 concentrations.) That means additional energy to the surface of 1 W (1 J/sec) for every square meter.
Now suppose you drop 1 ton of ice a distance of 1 kilometer, above every square meter of Earth’s surface. The energy added to the Earth is 10,000,000 joules on every square meter. That’s a lot… but adding that energy is the same as having that additional forcing for an extra 10,000,000 seconds, or about four months.
You can thus think of the net effect as reaching equilibrium about four months sooner than otherwise. Which doesn’t actually make a big difference. Melting of ice does represent a much larger heat sink (which soaks up rather than supplies energy) and it is part of the delay in reaching equilibrium… warming in the pipeline. But it still falls behind the energy it takes to heat up the ocean to the new equilibrium state, and this an aspect of the climate system where there is a long way to go to model it accurately. It’s also a major open question for measurement of energy flows going on at present.
This isn’t a direct answer to your question, but it is an interest aspect of the basic problem you are thinking about!
Comment by Chris Ho-Stuart — 30 Jul 2010 @ 10:02 PM
@ catman306 — 30 July 2010 @ 6:27 AM”Does anyone know whether the kinetic energy of a falling or disintegrating glacier or ice sheet is included in the equations for modeling melting ice?”
“We find that more melting has occurred than can be explained by the release of potential energy from the drainage of surface meltwater during one melt season suggesting that these moulins are persistent for multiple years.” http://www.agu.org/pubs/crossref/2010/2009GL041108.shtml
“6.1 Energy balance equation
The energy balance equation in the form suitable to calculate ice temperature within a glacier is the advection-diusion equation which in a spatially fixed (Eulerian) reference frame is given by….[equation]…
The heat production (source term) P can be due to different processes: Dissipation In viscous flow the dissipation due to ice deformation (heat release due to internal friction) …[more equations]… Sliding friction The heat production is the rate of loss of potential energy as an
ice column of thickness H moves down slope.” people.ee.ethz.ch/~luthi/pdf/script/chapter6.pdf
I ask you all this simple question: Since 1900, where have the hundreds of billions of pounds of rubber and asphalt dust gone?
The short simple answer is: Anywhere and everywhere! Every year the amount of this dust released into the enviroment keeps increasing. Rubber particles do not degrade when exposed sunlight, air or microbes.
Try this: Take Post-It note and dab it on the dust on the top of your car until it doesn’t stick anymore. Then examine the dirty sticky strip with viewer with about 30x magnificaton. Note the enormous amount of tiny black particles. Also note numerous highly reflective particles which are probaby mica from the rocks in concrete.
Another source of light-absorbing particles is metallic dust from disk rotors and brake drums as well as the rust that falls off cars and is ground to tiny particles by tires.
In southern Caifornia the rubber and asphalt dust could act as an accelerant for brush fires. Homeowners there should probably wash off the roofs of their houses before fire season.
Since most major cities are located on the coasts of the continents, it would be of interest to determine concentration of these black particle in the ocean waters.
Lastly, we city folks breath in the really tiny particles (5 microns<) of rubber and asplhalt dust, and these probably cause respiratory problems such as asthma in childern. Car tires contain about 40% natural latex to which many people are allergic.
I googled "tire dust" and found one article that states that about 600,000 mectic tons of rubber dust is released into the enviroment every year in the US.
Comment by Harold Pierce Jr — 31 Jul 2010 @ 12:28 AM
35 years on and although some countries have implemented some measures to mitigate carbon emissions, globally we are increasing emissions before the recent recession hit.
35 years on and the USA and Europe have achieved nothing in terms of carbon mitigation.
Harold (109) asks about tyre dust. I wonder about it too. It travels long distances. We had report years ago that in certain conditions it floated across from the continent of Europe to the UK. But what are its properties as a climate forcing agent?
Thanks Chris, I seem to recall something about Arrhenius saying if humans increase CO2 it would be great because we don’t want to go into another ice age. It might have been from Spencers work, but I will have to dig around.
John…one spot this is mentioned is in Naomi Oreskes’ talk on the denial of global warming. She mentions Arrhenius thought GW would be a good thing.
Comment by Daniel J. Andrews — 31 Jul 2010 @ 8:26 AM
#112 Daniel J. Andrews
Yes, I have read that and heard it in several places. In context, the CO2 output of humans was much smaller then. So if a little CO2 could prevent the next ice age, then that probably didn’t sound to o bad.
I don’t think anyone in that time period imagined that we would jack up our output to such amazing levels as we have.
#112 Daniel J. Andrews: “…Arrhenius thought GW would be a good thing.”
Even Bert Bolin, the founding father of the IPCC, thought GW might be a good thing for Scandinavia. At least he said so when I interviewed him in 1990. What scared him was the consequences for Africa and Asia.
Comment by Lars Rosenberg — 31 Jul 2010 @ 12:55 PM
"It is estimated that over 600,000,000 passenger cars travel the streets and roads of the world today.
In the United States alone, 247,421,120 "highway" registered vehicles were counted in 2005, of which 136,568,083 passenger cars. (Bureau of Transportation Statistics U.S. Department of Transportation)" http://www.worldometers.info/cars/
600/136=4.4 times the US tire dust for the world as a whole, assuming the same vehicle usage - probably an overestimate, but dust from unpaved roads more common outside the US probably is significant.
4.4*600k=2.6 million metric tons of tire dust worldwide, or ~20% of the total black carbon soot(partial combustion of fossil and biofuels) emissions. Not dominant in forcing, but certainly significant - maybe we need white tires and roads worldwide for indirect albedo geoengineering? Use white marble dust and silica fume instead of carbon black as rubber fillers, and use a wear layer of limestone + white portland cement on the roads.
The residence time of dust in the atmosphere is short - the fine sulfates from Pinatubo were gone in a couple of years, and mechanical dusts will have a larger particle size distribution than the sulfate condensates from volcanic eruptions or combustion – since they act as nucleation centers for precipitation, and the larger mechanically produced particles also sink gravitationally.
“Humanity stands … before a great problem of finding new raw materials and new sources of energy that shall never become exhausted. In the meantime we must not waste what we have, but must leave as much as possible for coming generations.” — Svante Arrhenius http://www.todayinsci.com/A/Arrhenius_Svante/ArrheniusSvante-Quotations.htm
He not only anticipated global warming, but peak oil(coal/uranium…)!
1)This is amazing data and of critical importance to Net Primary Production. This means that a large fraction of the CO2 uptake capacity of the oceans has been declining for over a century. Why was this not detected earlier in other studies of carbon balance ?
From my Hub article on Arrhenius, here’s a quote from his grandson, Gustaf, an oceanographer who enjoyed a distinguished career at Scripps:
Well, my grandfather rang a bell, indeed, and people became extremely interested in it at that time. There was a great flurry of interest in it, but not because of the menace but because it would be so great. He felt that it would be marvelous to have an improved climate in “the northern climes.” And in addition, the carbon dioxide would stimulate growth of crops—they would grow better. So he was–he and people at the time were–not unhappy about the prospects. They were only sad that in his calculations it would take about 300 years for it to have the marked effect that we now think would happen in something like thirty or forty years.
We have konwn, for a long time, that the relationship between CO2 and a warming climate was known in the 1800′s.
The issue is not how long it has been recognised in modern science or whether it is “settled science” today.
The issue is the number of people and businesses who have a vested interest in “Settling” the “Science” 6 feet under, preferrably in an unmarked grave.
Until that is resolved, then this argument will rage on and on and on.
As an aside, reading the last dozen or so posts, I wonder if anyone has ever modelled the change over from Asbestos brake materials in motor vehicles? Given the very high levels of asbestos particles in the atmosphere up to the 1990′s and their well knownw insulating properties and reflective capacity.
Certain parts of the science can be safely called settled science.
- We are warming
- Humans are causing the warming trend due to increased GHG/forcing
you can toss more than a few things in that bucket.
The unsettled part is regional influence, ocean heat content overturn, intra and inter-decadal influences, time scales, and then a lot more things can be thrown in that bucket.
So the settled part is we are doing it and its going to get warmer, and that will have more than a few negative impacts on modern infrastructure and therefore the plants, animals and humans that live here.
Radio Free Liberty has written an article about an unhelpful and highly-publicized Russian conspiracy theory about global warming. RL called the Russian author and got him to back-off his claim that US scientists are using “climate weapons”…”to provoke droughts, erase crops, and induce various anomalous phenomena in certain countries.”
“Asked whether or not Russia was also experimenting with climate-control methods, Areshev said since he was not a member of the government, he did not have information about such projects.”
Well, he’s not a member of the American government, either.
As an aside, reading the last dozen or so posts, I wonder if anyone has ever modelled the change over from Asbestos brake materials in motor vehicles? Given the very high levels of asbestos particles in the atmosphere up to the 1990’s and their well knownw insulating properties and reflective capacity.
The insulating properties of asbestos are primarily due to air pockets between the fibers. Loose asbestos particles do not have any particular insulating properties. (Their reflective properties are still interesting.)
phytoplankton huh, well quite recently there was this finding of the missing megafauna and the mega-poop… each whale good for 2 tonnes of ferro injection annual. Seemingly 300 years ago there were an estimated 94,000 grey whales in the Atlantic… think there is/was one now somewhere in the Med (which is thought to have gotten there by swimming from the Pacific via the Arctic… the Suez is not probable, nor rounding the Cape.
Issue#16 (Special Issue 2010) of SciDAC Review (Scientifc Discovery thorugh Advanced Computing) is all about the roadmap to exacale computing, 10^18 operations/second. I found all the articles of interest; one is about climate modeling.
> This means that a large fraction of the CO2 uptake capacity
> of the oceans has been declining for over a century.
Maybe so, seems likely, but what’s your source on this belief?
Do you know which species are changing? phytoplankton? zooplankton?
> Why was this not detected earlier in other studies of carbon balance ?
What “this” do you think was not detected earlier?
“This” decline in plankton counts worldwide? Data collected for other reasons are collected in this study. Why not earlier? Lack of funding?
“This” change in the CO2 sink in the oceans? Why do you believe it wasn’t detected? Have you looked, or are you just assuming nobody detected a change? How would you find this out?
One example of what you can find by looking–just a place to start, with links: http://www.cccma.ec.gc.ca/papers/ngillett/PDFS/1735.pdf
Saturation of the Southern Ocean CO2 Sink Due to Recent Climate Change Corinne Le Quéré, et al. Science 316, 1735 (2007);
“… Relatively little attention had been given to the quantification of the trends in CO2 emissions and sinks until after the publication of the fourth assessment of the Intergovernmental Panel on Climate Change (IPCC-2007). At the close of IPCC-2007, many questions remained open, particularly regarding the response of the CO2 sinks to elevated CO2 and climate change . This paper reviews the recent publications that analyse evidence of recent trends in the CO2 sinks published since IPCC-2007. It discusses the available evidence and the various interpretations of the underlying drivers, and recommends ways to improve our knowledge and understanding….
It is only recently that sufficient observations exist to constrain the trends in various components of the global carbon cycle. The detection of trends is thus necessarily controversial, because we are at the detection limit of the information. Another decade of observations will certainly help clarify the significance and causes of the observed trends, but time can be gained by improving synergies between models and observations. Improved constraints on the CO2 sinks would put us in a far better position to project the expected changes this century, to assess the potential for large and/or abrupt changes in biogeochemical cycles with consequences for future climate, and possibly to even provide independent information to constrain the reported emissions of CO2 at the level of large regions . Such information is important to sustain climate policies and monitor their implementation.
To produce information relevant to climate policies however, there is an urgent need to reduce uncertainties in recent trends and to improve confidence in their attribution and in future projections. Progress can be made immediately on three fronts ….”
Remember that when you see a flood of statements trying to convince you that “we don’t know, we can’t know”* — from people arguing that more science can’t help reduce uncertainty. Wrong; plenty of ways known to improve what we know.
The first sentence of the Boyce paper states that one half of primary production is phytoplankton. This is after 1%/yr decline for a hundred years, which means a hundred years ago, more than 1/(1-0.01)^100 = 2.7 times current primary production was phytoplankton. How can this be, unless a large carbon sink has appeared over that last century, and if so, where is it ?
This is a fascinating thread. The historical context illustrates an important point that is not made often enough. The deniers often refuse to give AGW credence because they say it is all based on questionable temperature data. However, the science is really based on physics. The temperature data simply confirms the physics and allows us to more accurately quantify the effect.
I’m not at all sure that oceanic carbon sequestration correlates with phytoplankton levels. Sequestration will be the excess carbon taken up after decay and loss of CO2 to the atmosphere is taken into account. The same suppression of convection that causes the loss of nutrients might allow the organic carbon (dead animal/plant life and poop) to sink to the bottom. So it is possible that oceanic carbon sequestration could go either way as a result of a phytoplantion collapse. Some people think a phyto collapse means the end of Oxygen, or a deadly climate/CO2 feedback. I don’t think those effects are nearly strong enough. But, a serious reduction in the biological productivity of the sea would be a big deal.
Sidd @131 – “but my question still stands, what is the new carbon sink that has appeared over the last century ?”
Perhaps there isn’t one?. I take it you’re assuming a corresponding decrease in the oceans uptake of atmospheric CO2 to match that of the decline in phytoplankton abundance. Not sure that that such a simple relationship exists, as some earlier coupled climate model runs, which include carbon cycle feedbacks, predicted only minor changes to the oceanic carbon sink.
“In our experiment, increased thermal stratification due to warming of the sea surface suppresses upwelling, which reduces nutrient availability and lowers primary production by about 5%. However, ocean-only tests suggest a small effect of climate change on oceanic carbon uptake, as this reduction in the biological pump is compensated by reduced upwelling of deep waters which have high concentrations of total carbon.”
To assume that phytoplankton are the only sink for CO2 seems rather bizarre to me. As the oceans become less hospitable to phytoplankton, those niches will open to other species–probably species which don’t benefit us by producing oxygen.
What is more, much of the ocean carbon sink is explainable in terms of simple physical chemistry.
Re step 3 (predicting the temperature response), in a paper in PNAS, Ramanathan and Feng suggested that the warming we are already committed to is 2.4 deg C, and that this is being masked chiefly by aerosols and to a
lesser degree delayed by ocean thermal inertia. Their argument is that
once societies clean up their act, a good part of this warming will
kick in. And that it is unavoidable. (V.Ramanathan and Y. Feng, ‘On Avoiding Dangerous Anthropogenic Interference with the Climate System: Formidable Challenges Ahead’, PNAS, vol. 105, no. 38, pp. 14245-50).
Prof James Hansen, and doubtless others, have made the point that data for the last 7,00,000 years shows that a forcing of 1W/m2 yields a temperature increase of 0.75 C. Now, IPCC AR4 suggests a GHG forcing so far of roughly 3 W/m2 since the Indus Rev (the large negative aerosol forcing takes it much lower), hence it would yield a committed warming of over 2 deg C (even assuming dangerous warming is 2 deg C, likely lower).
So does that suggest a larger temperature increase from emissions already made than is commonly understood?
sidd, if there’s an expert reading here who works in the field of ocean plankton and climate, perhaps we can tempt that person to speak up. So far it’s all just us readers here poking at a huge new field of research.
You need to distinguish
– CO2 going into solution in seawater (mixing into the upper layer depending on temperature and wind/wave mixing, then mixing into deeper water over time, changing the pH as it does)
– CO2 available in the photic zone that is used for photosynthesis
(for a start into the paleo work, try: http://www.nature.com/nature/journal/v407/n6801/full/407143a0.html http://www.nature.com/nature/journal/v407/n6803/full/407467a0.html
Global change: Plankton cooled a greenhouse
“Scientists who can perform laboratory experiments are lucky — a megalomaniac climatologist can only dream of putting an Earth-like planet in a giant test tube, pumping billions of tonnes of CO2 into its atmosphere, and registering the effects on life and climate. Fortunately, there are other approaches….”
– what happens to that ‘primary production’ of carbon compounds?
More CO2 in the air; more CO2 going into the oceans far faster than in paleo events, too fast for the biological recycling found in the paleo record. So ocean pH changes far faster than in the paleo record. So the biology changes under new pressures.
Want a funny irony? People in the US are urged to eat more of the ocean fish (salmon/sardines/anchovies) for omega-3 fats, otherwise scarce in the US diet (removed from processed food to extend shelf life). (Aside: see http://efaeducation.nih.gov/ . Be warned, nutrition science has vested interests, this is a hot topic; the ‘blog science’ about nutrition gets wackaloonier even than climate blogs).
That form comes mostly from primary production in the ocean (plankton float, so don’t invest energy making roots, stems and seeds with the stiffer omega-6 form we get too much of, eating land plants).
The food produced by the plankton is changing. Look up “junk food” +seabirds for some of the work. It’s new science, the work is scattered, and there’s plenty to read. One example:
“These diving seabirds were having a terrible breeding season in the United Kingdom, and some colonies hatched no chicks at all. But Wanless could see that parent birds were catching as many fish as ever, if not more. “We couldn’t work out what was going wrong,” she said. The light dawned when she and her colleagues measured the fat and protein in the fish being caught, mostly sprat, a member of the herring family. Compared with previous years, the amount of energy a hungry guillemot received from a 10-centimeter sprat plunged in 2004, dropping from 55 kilojoules to 12 kilojoules. “They were largely water,” Wanless says.
Wanless concludes that the guillemots (Uria aalge) were suffering from a diet of what some ecologists have called marine “junk food.” They hypothesize that in some cases, marine predators’ prey is being replaced by less nutritious species ….
… This summer, the U.K.’s Royal Society for the Protection of Birds reported that “virtually no” chicks fledged from some kittiwake and tern colonies. The main cause is thought to be changes to fish populations due to fishing and the effects of global warming on fishes’ planktonic food species, because the North Sea is now 1.5°C warmer than it was 40 years ago. The warming has resulted in a 70% drop in the populations of a tiny crustacean called Calanus finmarchicus, thought to be the main food of sprat and sand eels, as well as a rise in the numbers of a warm-water relative, C. helgolandicus, which contains much less fat and so is junk food for the fish…. http://www.sciencemag.org/cgi/reprint/322/5909/1786.pdf
Another blast from the past: The post sent me back to some dusty bookshelves for an old popular science work, a 1964 translation of a 1962 Time-LIFE book by Arthur Beiser, The Earth. (Perhaps some other reader has the English original? Google Books displays a snippet with the relevant quote on p. 163, but gives the date as 1980, so it may be a later edition.)
Beiser noted that humanity may be able to influence climate and glaciations. Growth in industrial activity, as well as deforestation, had led to huge CO2 emissions. Half of the emitted CO2 had been quickly removed by various chemical processes, while the rest remained in the atmosphere, raising its CO2 content by 13%. CO2 prevented long-wave heat radiation from the earth from escaping, and therefore, this change in the composition of the air had led to a mean temperature rise of perhaps 0.5ºC. The CO2 concentration was set to grow over the coming centuries, leading to a gradual increase of the earth’s mean temperature.
Beiser at the time had his doubts about Wegener’s continental drift theory, but seems to have taken anthropogenic global warming as pretty much cut and dried.
Happy Birthday to AGW awareness. To bad people are still so unaware & that unawareness seems to be getting stronger and more vicious, as the proof in the pudding gets stronger and stronger, and great sites like RC debunk the falsehoods as fast as they come out. Thanks, RC!
Skeptical Science did a piece on Thompson’s article. Thompson (the author of the article in question) weighed in to defend his piece, eventually ended up modifying the article in response to the dialog there. Science of Doom also did a treatment.
Sidd @134. I’m not an expert, and so I won’t attempt to do more than throw out ideas. I’ll await the real experts. Thats why I come to RC.
I suggest we wait for a RC post on the phytoplanton issue. Seems like if confirmed it should be of great concern.
Medvedev, 30 July: “What’s happening with the planet’s climate right now needs to be a wake-up call to all of us, meaning all heads of state, all heads of social organizations, in order to take a more energetic approach to countering the global changes to the climate” http://bit.ly/MedvClim
Thanks for that. It does give good perspective that global warming was really recognized at that time as human related and from that perspective, not a bad thing. As I pointed out before, the emission rates were so much lower, I don’t think they could imagine the burn rates of today.
My quick reading of the American “Thinker” blog science, and the Skeptical Science and Science of Doom rebuttals resulted in the 4 sentence summary below. I think this is about right but I’d be happy to hear if I totally misinterpreted the Skeptical Science and Science of Doom pieces.
It looks to me like Gary Thompson claimed that the models make a specific claim (namely that the OLR should decrease) that was contradicted by the data and that he had therefore “disproven AGW.” But, as the Skeptical Science and Science of Doom commentaries point out the models don’t actually make the prediction claimed by Gary Thompson consequently his argument is simply false. To know what the models predict requires fine scale vertical temperature and humidity profiles which are obtained from modeling. Thompson ignored all this and consequently his claim is just another Wizard of Oz character (i.e. a straw man) .
This is the fundamental problem with “blog science”. Nonsense gets “published” and it is very difficult to sort it out unless you’re an expert in the field. That’s why sites like RC, Science of Doom, Skeptical Science are so valuable. Now Thompson appears to be a reasonable character. If he is as reasonable as he appears to be he will flesh out his claims and try to publish them in a legitimate climate science journal.
When G Rowatt (#154) asked “what would have happened if we hadn’t spent a dime on the whole shebang” — the shebang being the scientific study of global warming, one presumes? — ReCAPTCHA immediately came up with this answer:
I thought we had left ‘global warming’ in the past and substituted ‘climate change in its place,simply averageing out global temperatures and saying they are rising tells us nothing and oversimplifies a complex situation[as with recent arctic/european cooling [gives amunition to the climate sceptics].
You are welcome, John. (And thanks for all that you are doing on an ongoing basis!)
You are certainly right about the burn rates, as you put it–IIRC, Arrhenius–and perhaps even Callendar?–did not envision the exponential growth in emissions actually observed.
Also, though, neither man had experienced the “ecological revolution”–the shift in paradigm which made many more of us aware of how deeply linked apparently disparate natural phenomena can be–especially in the biological sphere. If you just look at first-order effects of warming, it may not “look” too bad.
Certainly, I fairly regularly encounter folks online whose imagination of GW pretty much stops with the immediate effect of a couple of degrees–that just seems like a negligible amount to them. Who cares (they think) if it’s 32 C instead of just 30? They don’t stop to think about (for example) how far geographically that might shift climate zones, and how easy or hard it might be for vegetation to follow.
And it’s a whole different conceptual framework again to ask about predator/prey relationships, temporal shifts in migration, fruiting or hibernation patterns, or even (shifting back to the meteorological sphere) second-order effects such as changes in precipitation.
Certainly Arrhenius was NOT lacking in imagination–if you know his story at all, that’s an understatement monumental enough to be funny!–nor was Callendar. But one can’t expect even such exceptional minds to anticipate everything the next couple of generations come up with. We live in a very different conceptual space today than did people of the early 20th century.
(Hmm, is Captcha hinting I’ve gone on too long? “yield: pettifog”!)
Nagraj Adve (#138):
Ramanathan and Feng equate stabilization at constant concentration with “commitment”. That “committed” warming is larger than the case of eventual zero emission. See the article here Climate Change Commitment II by Gavin on 2 June 2010.
It is a big challenge to achieve eventual zero emission, of course.
I have a question for big Joe Romm. It is widely accepted in the science community that we had 7,000ppm of co2 in the atmosphere during the time of the dinosaurs. We now have 385ppm.
First question: Where did all of that co2 go? Did the oceans absorb most of it? If so, why are we worrying about 385ppm, which is such a smaller number. Also, there is an argument that we are adding co2 at a very fast rate. I think this is probably false. Consider that dinosaur excrement gave off massive amounts of methane, which may have triggered carbon sinks to release massive amounts of co2.
2. Carbon Dioxide has existed on earth for billions of years. It took scientists centuries to figure out how fire worked. Many believed that a chemical known as “phlogiston” was released. Mr. Romm, I think you should consider the reprecussions of a sustained drop in global temperatures over a period of several years. If this happens, you will be shown no mercy, and rightfully so. It is hard for me to believe that you have so much confidence in global warming theory considering that it is a vastly more complex issue than how “fire” is created.
[Response: Good point, I've made a note of that.--Jim]
I want everyone to remember that average co2 levels throughout earth’s history are higher than the level we are at today. We had 7,000ppm of co2 and now…385. This is a tremendous difference and it is important to remember that this was achieved by nature, not man. Nature put a ton of co2 into the atmosphere and nature removed it. I will leave everyone with a question:
Since the earth was able to remove massive amounts of co2, why then, can it not remove a much smaller amount? Are we to believe that the earth cannot do something it has already done, and on a much smaller scale?
Dear Dr. Shooshmon,
I agree wholeheartedly with your comment on the levels of co2 on earth. What I so not understand is why people are convinced global warming is manmade if the levels of co2 and global temperature have been long before people were around.
[Response: "Dr. Shooshmon" is not even even sure which blog he is at. The answer to your question is simple: the fact that other physical causes of climate change do exist, have operated in the past, and will do so in the future, does not negate the very solidly supported conclusion that greenhouse gases, varying in the range of concentrations they have over the recent past and present, can also do so. Start reading.--Jim]
Comment by red white and blue — 4 Aug 2010 @ 5:07 PM
shooshmon@161 — Recent evidence has made me very skeptical indeed of claims of CO2 concentrations much exceeding 1000 ppm at any time in the past nearly 4 billion years.
As for eliminating CO2, weatherizing rock has removed CO2 faster than new sources supplied for most of the past 45 million years or so. For or current dilema and the time scales involved, do read David Archer’s “The Long Thaw”.
- The age of the Dinosaurs was the Mesozoic (higher CO2 amount, but probably nowhere near 7000 ppm), not the early Paleozoic (for which, 7000 ppm is an upper-end estimate)
(also for your interest, the sun gets significantly brighter over 100s of millions of years; there is continental drift and orogenies and erosion, biological evolution; even the coriolis effect, the tides, and the periods of the Milankovitch cycles change over 100s of millions of years)
- Different processes become omore or less important on different time scales. Natural processes (if we don’t get to it first) almost certainly will absorb anthropogenic CO2 emissions, but they won’t do so overnight.
When some amount of CO2 is dumped into the atmosphere from fossil fuels, it increases the total C of the atmosphere + biomass and soil + upper ocean + rest of ocean. The amount in the atmosphere decreases as it spreads out to these other reservoirs, but this spreading occurs on different timescales – it happens relatively quickly between the atmosphere and upper ocean; hence the rate of CO2 increase in the atmosphere has been significantly less than 100 % of the ongoing anthropogenic emission rate. This by itself can’t remove all the additional CO2 from the atmosphere, and it is limited by the supply of ions to the water…
(from dissolution of carbonate minerals (buffers pH) and chemical weathering (I presume that also increases pH) – the later supplies ions to feed the formation of carbonate minerals and is thus required for inorganic C geologic sequestration, but both increase the amount of CO2 the water can hold (I think for a given partial pressure, etc … I don’t know all the details of that but I have a general understanding sufficient for this comment; dissolved CaCO3 is Ca ions and CO3 ions, the later reacts with dissolved CO2 to form HCO3 ions (bicarbonate); the supply of Ca ions from chemical weathering allows CaCO3 precipitation with net removal of CO2 from air)
…; the spreading of CO2 from the upper ocean to the deeper ocean takes CO2 out of both the upper ocean and atmosphere (as CO2 is removed from the atmosphere), but the oceanic overturning required takes on the order of 1000 years.
(There can also be some spreading of CO2 into biomass+soil, but the effect is also limited – biomass+soil C won’t simply increase until the atmospheric level returns to a previous value.)
And then their’s the timescale of carbonate mineral dissolution that allows the ocean to hold more inorganic C while buffering the pH – hence, short term massive fluxes of CO2 into the atmosphere from other than the ocean itself will perturb the pH of the water for a time.
The timescale of removal of inorganic C from the whole atmosphere+ocean takes even longer, though it is fast enough to account for the variation in CO2 on the geologic timescales you refered to (it’s rate also responds to climate, with the ability (depending on geography and CO2 itself and probably some other things) to act as a negative feedback (with possible exceptions, such as glacial enhancement of chemical weathering) (and to stabilize the atmospheric+ocean+surface organi C amount, to an equilibrium value depending in part on fluctuations in geologic emission) – this negative feedback could help stabilize the climate on long timescales but is typically ineffective on shorter timescales – it was not able to prevent the ice age – interglacial variations, for example).
Of course, there are also shorter-term climate feedbacks on the C cycles to consider.
Bottom line – the Earth in some millions of years’ time from now probably won’t look drastically different one way or another based on human actions over the next few hundred years…
(? – butterfly effects and, very hopefully, ongoing existence of human civilization, aside – there is of course the recovery time from an extinction event if it gets that bad, afterwhich the result might be broadly similar, or not, but different in details, of course (the biological climate might stay similar even if the specifics of biological weather are completely different …))
… but that’s not the primary concern for policymaking or even scientific study of AGW/ACC.
Maybe I’m being too generous here…but my impression was that “Dr.” Shoosmon’s long post was pure parody…and a cracking good parody of a denialist, at that! I found his (now edited) closing to be his way of letting us know that his tongue was firmly in cheek.
Broecker’s paper may have been published in 1975, but you now how it is: We scienctists keep published “old news”.
If you look at the graph, the temperature kept going up from 1971-1974. No wonder Broecker “predicted” global warming. When I was a child in the early 1970s, I remember climatologist predicted a new ice age. It was based on the same graph. Apparently, one can predict whatever one likes. Or, the climate cannot be predicted upfront. What concerns me: I recently read about the plateauing of the T-graph since 1998. Is it true? If so, how can that be reconciled with the ongoing increase of CO2?
Dr P. Borger, biologist
[Response: Your memory isn't quite accurate. Please read up on the facts of the matter. There's an explanation of the 1970's cooling myth here and the 'global warming has stopped' myth here]
@Chris : Indeed most depressing “Happy Birthday” ever.
But thanks realclimate for the perseverance. One day we’ll start having breakthroughs, like a positive Black Swan appearing out of nothing, in areas we didn’t expect, unpredictable like the fall of the USSR or the rise of the internet and most likely driven mostly by complex bottom-up forces instead of pure top-down actions (although both are needed).
“If you look at the graph, the temperature kept going up from 1971-1974. No wonder Broecker “predicted” global warming. When I was a child in the early 1970s, I remember climatologist predicted a new ice age. It was based on the same graph. ”
As Gavin said, your memory is a bit off here, Dr. Borger. You will note that the graph in question is credited to NASA GISS–ie., Gistemp. Obviously, this isn’t “the same graph” used by Broecker or for that matter by Kukla & Matthews or Rasool & Schneider. But perhaps you may have been thinking that the years since 1975 belong to the same dataset appropriately updated?
If so, I’m afraid you are quite mistaken. The Gistemp home page explains the history:
The basic GISS temperature analysis scheme was defined in the late 1970s by James Hansen when a method of estimating global temperature change was needed for comparison with one-dimensional global climate models. Prior temperature analyses, most notably those of Murray Mitchell, covered only 20-90°N latitudes. . . Our first published results [were] (Hansen et al. 1981). . .
So you see, the very dataset from which the present graph is drawn did not exist in 1975, much less earlier in the 70s, when concern about possible cooling was more current.
And if the proffered Captcha sample is ambiguous, click the little circling arrows (above the loudspeaker icon) and it’ll give you another; continue til one is readable; or the loudspeaker will read it out loud.
1) Joe Romm is of about average size (and thus rarely goes by “Big Joe Romm” as you assert).
2) Joe’s website is Climate Progress. This is RealClimate. They are two different climate change blogs.
3) As the link below shows, it is not accepted by anyone, no matter how widely, that there was 7,000 ppm of CO2 during the time of the dinosaurs. As the graph below indicates, the high estimates peak just over 2000 ppm during this time (220 to 65 million years ago), with the average of the four graphs being closer to 1000 ppm.
4) 7,000 ppm is conjecture by one of these four sources going back half a billion years, soon after complex life had formed, and 100 million years before plants and then other life forms evolved onto land.
5) The annual average concentration of CO2 is now 390, not 385 ppm. With methane and nitrous oxide, the CO2 equivalency is over 430 ppm.
6) The human burning of fossil fuels contributes 100 to 130 times the CO2 that volcanoes, the next largest source, contribute in an average year.
6) You write “Mr. Romm” but Joe has his PhD in physics from MIT, making him also a Dr.
7) You write “Consider that dinosaur excrement gave off massive amounts of methane, which may have triggered carbon sinks to release massive amounts of co2.”
One negative feedback that may have absorbed much of the CO2 spike from the PETM 55 million years ago was the formation of the Himalayas with all that new rock to absorb CO2 through weathering. Maybe our biggest hope this time is the Himalayan-sized heap of steaming dinosaur excrement in your comment.
Oh, and Happy Birthday and this is a great post. Nobel Prize winner Svante Arrhenius estimated a 9 degree Fahrenheit increase in temperature if CO2 doubled from pre-industrial 280 to 560 ppm in a now-famous paper he published in 1896. (Because he wrote in an even cooler than now Sweden, Arrhenius thought of global warming as a positive.)
I respect the German comments and their relatively (to our) far-sighted government adopting plans to address global warming in 1985.
The corresponding year in the U.S. and the rest of the world is 1988, when Hansen testified to Congress during a heat wave. (How does he orchestrate things like that and the Pinatubo eruption? How high do his connections go?) Also that was when the IPCC was formed. The U.S. had a very significant heat wave that summer that drove the point home, with the massive Yellowstone fire, etc.
The theory was in place from Arrhenius, Keeling and all the others mentioned here, with Broecker convinced by 1975 and Schneider by 1979, but anyone paying attention should have been convinced by 1988, with CO2 greenhouse effects overcoming aerosol effects beginning around 1975.
Of course as with Newton’s apple, Shooshmon’s stepping into dinosaur excrement alerted him to global warming in 499,997,990 BC.
Re #63, and Eric’s response to #10 (temperatures in North America)
Even if British Columbia would show a temperature increase in recent decades, for the whole of the US there is a flat curve for the period 1901-2000, with a trend value of 0.10 degrees F per decade. See monitoring data at http://www.ncdc.noaa.gov
Over at SkepticalScience various folks have been digging into the cellar to find still-drinkable bottles of uncertainty made of mangled and then fermented interpretations of GCMs mostly produced in unsanitary conditions. Turns out almost everything’s gone to vinegar, quite undrinkable and refused forthwith if served and no wonder.
However, there are still some dusty bottles labeled “Clouds,” with vintages stretching back years.
Is there any chance that RealClimate could pull out a corkscrew, open some of these bottles and treat us to a sampling of where the issue of clouds and GCMs stands today? A flight with some expert comments would go down nicely at this point.
I find in reading those sites that say that climate problems are a myth that their evidence is very sparse and inconclusive. Recently I read Book 1 of the free e-book series “In Search of Utopia” (http://andgulliverreturns.info), it blasts their lack of evidence relative to several myths. The book, actually the last half of the book, takes on the skeptics in global warming, overpopulation, lack of fresh water, lack of food, and other areas where people deny the evidence. I strongly suggest that anyone wanting to see the whole picture read the book, at least the last half. There is also up to date information at:http://www.newscientist.com/article/dn11462-climate-change-a-guide-for-the-perplexed.html
The strange thing on this is we know it for past 35 years and we are doing almost nothing about it. When every day people change their habits and think environmentally friendly, why politicians don’t do the same? Whom they want to save? The Economy? To sell cool fresh unpolluted air and clean and healthy water or even food could be a good business…
if comments are still open for this I was interested by the contribtution of non CO2 greenhouse gas and aerosols. You say they cancel out but how long will this continue? What is the time in the atmosphere of these gases compared to aerosols? How long will aersols cancel them out if air pollution is reduced?