Friday roundup

An eclectic round-up of the week’s climate science happenings (and an effort to keep specific threads clear of clutter).

It’s the sun! (not)

As regular readers here will know, the big problem for blaming the sun for the recent global warming is that there hasn’t been a trend in any index of solar activity since about 1960, and that includes direct measurements of solar output by satellites since 1979. Well, another paper, has come out saying exactly the same thing. This is notable because the lead author Mike Lockwood has worked extensively on solar physics and effects on climate and certainly can’t be credibly accused of wanting to minimise the role of solar forcing for nefarious pro-CO2 reasons!

Stefan was quoted in Nature as saying this is the ‘last nail in the coffin’ for solar enthusiasts, but a better rejoinder is a statement from Ray P: “That’s a coffin with so many nails in it already that the hard part is finding a place to hammer in a new one.”


The still-excruciating ‘Great Global Warming Swindle’ got another outing in Australia this week. The heavily edited ‘new’ version dumped some of the obviously fake stuff that was used the first time around, and edited out the misleading segment with Carl Wunsch. There is some amusing feedback in the post-show discussion panel and interview (via DeSmogBlog).

RC Wiki

As an aside, this is as good a time as any to point people to a new resource we are putting together: RC Wiki, which is an index to the various debunkings of the contrarian articles, TV programs, and internet pseudo-science that is out there. The idea is to have a one-stop shop so that anyone who comes across a piece and wants to know what the real story just has to start there. For instance, the page on TGGWS has a listing of many of the substantive criticisms from the time of the first showing.

Editing the wiki is by invitation only, but let us know if you want to help out, or if you have any suggestions or comments.

The sweet spot for climate predictability

Between the difficulty of long-term weather forecasts and the impossibility of accurate predictions for economic conditions a century hence, there is a sweet spot for climate forecasts. This spot, maybe between 20 and 50 years out, is where the emissions scenarios don’t matter too much (given the inertia of the system) and where the trends start to be discernible over the noise of year to year weather. Cox and Stephenson have a good discussion of the point in this week’s Science and a great conceptual graphic of the issues.

One could quibble with the details (we’d put the sweet spot a little earlier) but the underlying idea is sound, and in judging climate forecasts, it will be projections in that range that should be judged (i.e. the early Hansen projections).

350 comments on this post.
  1. FurryCatHerder:

    Re 145:

    I have a hard time imagining that it costs more to make them than it costs to buy them :) Or that the cost of the energy is greater than the cost of them.

    At any rate, all the ones I bought have paid for themselves. Assuming the amount of energy used is actually 4 times greater than what they cost in retail energy dollars (that’s the ratio of retail to wholesale electric costs here), they’ll have saved their energy in wholesale dollars in another 18 to 24 months.

    If LED lights come out sometime soon, I’ll figure out how many months until they’ve paid for themselves compared to CFLs and then replace. Or not.

    I’ll say this — if the denialists want to waste large amounts of money on gasoline and electricity, I guess that’s their right.

  2. Lawrence Brown:

    Regarding comment 147, a brief discussion of the results of the referenced paper by Mr. Armstrong, emphasizes uncertainties. The following is a quote from this discussion:

    “There is much uncertainty about the measurement of global temperature due to, for example, the coverage of weather stations and heat island effects in modern data, and the reliability of proxy temperature measures such as are obtained from ice cores and tree rings. Alternative measures have been proposed, but are not widely used in forecasting. Temperatures vary greatly over periods of hours and days as well as years, decades and centuries. Instabilities occur due to unpredictable events including, for example, volcanic eruptions and poorly understood phenomena such as El Nino weather patterns. Uncertainty over and instability in global temperatures mean that forecasts that depart dramatically from recent and longer term trends, such as those of dramatic global warming, cannot be justified.”

    There will always be uncertainties and this applies to all endeavors. To the best of my knowledge, heat island effects can be corrected for and in any case don’t change results significantly. They criticize the reliability of proxy measures, without specifically saying why. Proxies are indirect measures, granted, but have validity. Tree ring variability in thickness can indicate periods of wet and dry years, for example. The effects of volcanic eruptions are certainly well understood, and climate models have had great success in predicting the cooling effects due to the eruption of Mt. Pinatubo.
    I for one, would be glad to be wrong about global warming, but as far as I can tell the data and state of the art methods of analysis,that point to global warming, far outweigh the uncertainties.

  3. Barton Paul Levenson:

    Yesterday I added another page to my climatology site, which gives Judith Lean’s TSI (Solar Constant) data for 1610-2000, both in tabular and in chart form. The chart is especially revealing; you can clearly see the Maunder Minimum and the Little Ice Age, and also the roughly flat output for the last 50 years.

  4. Barton Paul Levenson:

    On optimism — I, for one, am not optimistic. I’m interested in the science behind global warming and will continue to defend it, but whether humanity will act in time is an entirely different question. Frankly, I don’t think we will. The time-honored human pattern is to wait for an acute crisis before doing anything, and by the time this crisis becomes acute, it will be too late. I think we’re very likely to trip the geophysical feedbacks (permafrost greenhouse gases, seabed sediment clathrate greenhouse gases, ice/albedo feedback) which will make the problem so much worse that we won’t have any way to fix it. Humanity will survive, and probably industrial civilization will survive in the long run, but we’re in a for a very long, very bad time, and probably a major decrease in population.

  5. Eric (skeptic):

    #134,135: David and Hank, it’s certainly not a simple issue (see for example), but my impression is that increases in upper clouds will generally be warming. It depends a lot on what they are covering, but high especially high thin clouds will tend to let in SW and trap LW whereas low clouds (warmer tops on IR satellite) will reflect more SW and let out more LW.

  6. tom:


    I wish I could somehow set up a wager with you on that one Barton, because I would Major sums of money that we will never suffer a large decrease in population due to the climate.

    For a number of other reasons, maybe, but not climate.

    In fact , if I had to rate # 1 it woul be a Shoemaker- Levy type comet.
    Considering that three of the fragments of Comet Shoemaker-Levy hit Jupiter with the equivalent of 6,000,000 megatons of TNT (750 times the world’s nuclear arsenal) each, I doubt there’s be too many people left.

  7. Ron Taylor:

    Re #147

    Armstrong’s challenge seems a bit like driving a stake on the beach as the tide starts in, then betting on how high the water will be on the stake precisely five minutes, ten minutes and thirty minutes later. It is impossible to know, since it depends on the waves. But you do know that five hours later, the reach of the water will be much higher. His challenge seems irrelevant to me.

  8. J.C.H:

    I disagree. Right now, the only technological solution assured to solve the problem that the world is capable of actually implementing is a significant reduction in the world’s population of human beings.

    It’s cheap; it’s easy; it can’t fail.

  9. Hank Roberts:

    Not true, JCH.

    That’s John Brunner’s solution from the ending of ‘Stand on Zanzibar’, lose the most selfish ten percent

    But in reality, two percent of the people on the planet own more than half of it.

    They bought it, they broke it, they can afford to fix it.

    It’ll cost them the world, but they have it to spend.

    Using the US as an example:

  10. pete best:

    Re #158, except for the fact that it goes against the human instinct to reproduce. With people living 2.5 additional years for every decade that passes it would be a good idea to reduce the human population but a significant one is a whole new ball game.

  11. Jim Cripwell:

    Ref 158. I am not sure what this has to do with climate change, but one, politically impossible, solution to the world’s population problem is to put all aid money into educating the females, and leave the males to do the best they can.

  12. Chip Knappenberger:

    Dear RC,

    Maybe in this week’s edition of Friday Roundup you’ll take on Al Gore’s inference that, if we are not careful, our fossil fuel emissions will turn the Earth into Venus and slowly roast us. He seems to be telling this story on his various speaking stops.

    We attempted to describe the actual situation, based largely on your “Lessons from Venus” article of last year. Maybe you all should dust it off again since it seems to have taken on renewed relevence.


    [Response: Glad to see you are keeping up on your reading. But you are expending a lot of effort on extrapolating things that Gore hasn’t said. You can point to Venus to demonstrate that CO2 forcing is capable of great things without suggesting that Earth is likely to end up the same way. Given the prevalence of people claiming that CO2 is saturated, it’s a good counter example. – gavin]

  13. Hank Roberts:

    Let’s look at what he said: Al Gore, his words:

    “…President Ronald Reagan said, ‘In our obsession with antagonisms of the moment, we often forget how much unites all the members of humanity. Perhaps we need some outside, universal threat to recognize this common bond. I occasionally think how quickly our differences would vanish if we were facing an alien threat from outside this world.’

    “We — all of us — now face a universal threat. Though it is not from outside this world, it is nevertheless cosmic in scale.

    “Consider this tale of two planets. Earth and Venus are almost exactly the same size, and have almost exactly the same amount of carbon. The difference is that most of the carbon on Earth is in the ground — having been deposited there by various forms of life over the last 600 million years — and most of the carbon on Venus is in the atmosphere.

    “As a result, while the average temperature on Earth is a pleasant 59 degrees, the average temperature on Venus is 867 degrees. True, Venus is closer to the Sun than we are, but the fault is not in our star; Venus is three times hotter on average than Mercury, which is right next to the Sun. It’s the carbon dioxide.

    “This threat also requires us, in Reagan’s phrase, to unite in recognition of our common bond.”

    — end excerpt —-

    Want to offer a direct quote, not a PR agency paraphrase crafted for your industry clients, Mr. Knappenberger?

  14. Lawrence Brown:

    About #154 on optimism. One of the indicators of global warming, in addition to temperature increases,is a multi study showing that hundreds of plant and animal species are shifting their range northward in the northern hemisphere consistent with global warming. Plants,insects,birds and fish are shifting either poleward or higher in elevation, and other behavioral changes,such as mating are taking place earlier in the spring.
    Our species can do many wonderful things, like writing beautiful symphonies, and solving differential equations, but when it comes to basic survival the lowly insect might have a superior sense of self preservation than we do.
    A lot of the controversy is rooted in initial increased costs in shifting over to different equipment and usage. But many of the new methods included in a new energy paradigm pay for themselves in a fairly short time, and even can reap profits if, for example, one can sell excess energy from electricity back to the utility company.

  15. Steve Reynolds:

    >Venus is three times hotter on average than Mercury…

    Not true.

    [Response: You’re right – it’s only twice as hot. That makes all the difference! – gavin]

  16. Henry Molvar:

    Twice as hot?

  17. TarunKJuyal:

    The study found that global warming since 1985 has been caused neither by an increase in solar radiation nor by a decrease in the flux of galactic cosmic rays. Some researchers had also suggested that the latter might influence global warming because the rays trigger cloud formation. I am write a blog which gave complete information about Global Warming.

  18. Hank Roberts:

    A degree here, a degree there, and before you know it you’re talking about a real problem.

    “…. temperature variations on Mercury are the most extreme in the solar system ranging from -183°C (-298 °F) to 427 °C (800 °F), although its average surface temperature is 167 °C (333 °F). In contrast, the average surface temperature on Venus is actually hotter at a very stable 464 °C (867 °F) because of its thick atmosphere.”

  19. David Price:

    A year or so ago a story appeared in the media that the Sun’s output was at it’s greatest for 12,000 years. Anybody know anything about this?

  20. David B. Benson:

    Re #169: David Price — Not much. However a little web trawling with search phrase ‘solar proxy ice core’ turned up

    Lonnie G. Thompson, et al., “Kilimanjaro Ice Core Records: Evidence of Holocene Climate Change in Tropical Africa”, Science 18 Oct 2002.

    This paper uses Delta14C as a proxy for solar variability, see the expanded version of Figure 3. Eyeballing this, it appears that the story you refer to appears to have missed a decimal point, since by the Delta14C proxy, it seems to have been as high, or higher, 1,400 years ago and almost as high 800 years ago.

  21. Tim McDermott:

    On optimism,

    Optimism is a good thing. It allows us to keep going. But there are knock-on effects to GW that are well outside the scope of climatogy. Take the northern movement of species. That only works with sufficiently mobile species. I’m afraid that our complex ecosystems, like the eastern (US) deciduous forest, will lose their climax species in the move north. The time for deciduous forests to get to climax is measured in centuries. Will the move north be slow enough?

    My real nightmare comes from the realization South Asia is going to suffer both the loss of glacier stabilization of very important rivers and the displacement of tens millions of people from rising sea level. And both India and Pakistan have nuclear weapons.

  22. Hank Roberts:

    I’ve looked for but not found “a story in the media” — where did you read it? Google turned up mention of “a National Academy of Sciences report that warned that the Earth is approaching the warmest temperatures in 12,000 years” — in one of Sen. Inhofe’s Republican Senate papers attacking the science. Not sure where the original is. But that’s about Earth not the sun’s temperature.

    This may help:
    Radiative Forcing of Climate Change: Expanding the Concept and Addressing Uncertainties (2005)
    Board on Atmospheric Sciences and Climate

  23. pete best:

    Some action.

    From the National Petroleum Council no less. Maybe Peak Oil and Gas is going be very good for climate change unless of course someone decides to turn up the coal volume.

  24. pete best:

    Is it possible for climate change to be affecting the jet stream because as the UK gets summer flooding this year souther Europe basks in a major heatwave. The jetstream has moved this year causing it to happen apparantly.

    Could climate change in any way be responsible for the jetstreams movement?

  25. Nick Gotts:

    Re #158-161. Slowing, then reversing global population growth can certainly contribute to reducing GHG emissions, but cannot solve the problem, because per capita emissions have been rising quite sharply since 2000, after several decades in which they were roughly stable, due to a reversal of the trend toward lower carbon intensity of energy supply. Moreover, the UNFCCC Annex 1 countries (i.e. rich ones) contain only 20% of global population but account for 46% of GHG emissions, according to IPCC’s AR4 SPM. Talk of a human “instinct to reproduce” is at best sloppy: people to a considerable extent choose how many children to have, are generally choosing to have fewer, and in some countries considerably fewer than necessary to keep the population stable. In Japan population is declining despite the world’s lowest death rate for any sizeable country, and large parts of Europe would also show declining population without immigration, despite low death rates. (Russia, some other east European countries and Botswana are also showing declines, but in these cases a recent rise in death rates due in most cases to socio-economic disruption and in Botswana to AIDS is important.) Although all such projections have associated uncertainties, global population growth is expected to continue to slow (it has been slowing in percentage terms since the 1960s and in absolute terms since around 2000), and reverse sometime in the second half of this century. As Jim Cripwell implies, educating girls is key to speeding the reversal in those countries that still have rapid growth, but urbanisation itself has a large effect, and we couldn’t stop that if we wanted to – the challenge there (so far as GHG emissions are concerned) is to make sure that process happens in ways that do not increase per capita emissions.

    A metacomment: without wishing to cast aspersions on anyone contributing here, I’m generally suspicious of claims that population growth is the key problem we face; they are often associated with considerable ignorance about what is actually happening to global and regional populations (e.g. the common and simply incorrect statements that global population is growing exponentially), and with attempts to blame the poor for problems largely caused by the rich.

  26. Hank Roberts:

    Good read on PR tactics:

  27. J.S. McIntyre:

    re 147:

    Maybe someone has commented, but if not:

    J. Scoot Armstrong is a Professor of Marketing are Warton Business School, Univ of Penn.

    Keston Green is a Senior Research Fellow of the Business and Economic Forecasting Unit at Monash University, Australia

    While I appreciate the two individuals have a history in terms of dealing with “scientific forecasting”, neither are climatologists, and I find it dubious to the extreme that they are somehow going to provide ironclad proof that, because of their methods, the climatologists have it all wrong.

    More important, IMHO, is the oft-remarked criticism re Why is it critics of Global Warming Theory and Prediction raealy have a background in Climatology, and further, why those that do tend to be out of date in terms of their current expertise to evaluate the work of people working in the field today.

    Mind you, I’m not tryingto say the paper is invalid – after all, I haven’t read it – but given the history of this sort of thing, can you understand why I would be skeptical?


  28. Hank Roberts:

    Type “Scott Armstrong” into the search box at the top of the page.
    And Gavin pointed a previous question to this:

  29. Nahan:

    Is the sun getting brighter or is more sunlight coming through the atmosphere? Because it hurts my eyes these days and it didn’t use to do that.

    Do you read Popular Science magazine there’s several Oil Company and U.S. Navy advertisements in that magazine. They recently had an “environmental” issue and the combined articles amount to saying that entrepreneurs and technological inventions will remedy all environmental disorders. Genetically engineered super trees to absorb more carbon, millions of giant pumps to bring cold water from the deep oceans to nullify hurricanes, and so on. What do you think about that?

  30. Timothy Chase:

    Re Scott Armstrong

    I did a kind of satirical summary of his “scientific forcasting” meta-methodology in post #25 of this thread based on the following paper:

    The sentences are a bit clunky, but the summary is actually fairly accurate, I’m afraid…

  31. Ron Taylor:

    The following paragraph from Armstrong’s paper is about all one needs to see its foolishness. (1) He seems unable to distinguish between the laws of physics and personal opinion. (2) The final sentence dismisses conservation of energy.

    “We concluded that the forecasts in the Report were not the outcome of scientific procedures. In effect, they were the opinions of scientists transformed by mathematics and obscured by complex writing. Research on forecasting has shown that experts’ predictions are not useful. Instead, policies should be based on forecasts from scientific forecasting methods. We have been unable to identify any scientific forecasts of global warming. Claims that the Earth will get warmer have no more credence than saying that it will get colder.”

  32. Hank Roberts:

    Nathan writes:

    > Is the sun getting brighter or is more sunlight coming through the atmosphere?


    > Because it hurts my eyes these days and it didn’t use to do that.

    You’re getting older, Nathan. It happens.

  33. Steve Reynolds:

    J.S. McIntyre> More important, IMHO, is the oft-remarked criticism re Why is it critics of Global Warming Theory and Prediction raealy have a background in Climatology, and further, why those that do tend to be out of date in terms of their current expertise to evaluate the work of people working in the field today.

    One possibility has been pointed out by others before: those are the scientists that do not have to please current climatology grant decision makers.

  34. David B. Benson:

    Re #174: pete best — Weather reporters on the telly oversimplify the weather system, often blaiming the jetstream for this-n-that.

    Hadley Centre has a report predicting climate changes region by region for the year 2050. They predict that the Mediterranean countries are going to become hot, for example.

    So I think it fair to say that Britian’s and Norway’s heavy rains are more likely to occur with climate change just as the heat around the Mediterranean Sea is more likely to occur with climate change.

    Which approximately answers your question.

  35. Ike Solem:

    A few notes on the ‘personal responsibility’ theme that some comments relate to (such as Ken Coffman’s). We know that the warming climate is real, and that this is due to changes in atmospheric composition, which are due to fossil fuel use and deforestation, the split being about 80-20, respectively, with uncertainties.

    Changes in your personal lifetsyle that eliminate your own fossil fuel CO2 emmissions and that reverse deforestation (go plant a tree!) are very commendable, but are insufficient.

    If your local lakes and rivers were heavily polluted with raw sewage because your city had no water treatment plant, than ‘personal choices’ would do little to solve the problem. If you built a one-person sewage treatment plant for your own house, your lakes and rivers would still be polluted.

    Thus, here are some suggestions:

    1) Lobby your government to promote the release of high-technology renewable energy patents to the developing world – yes, intellectual property rights do matter.

    2) Lobby your government to eliminate foriegn oil imports and replace them with domestic, renewable energy supplies.

    3) Lobby your government to enact regulations that will phase out coal-burning plants over then next 10-20 years and to institute programs that will bring solar and wind generation online as replacements.

    3) If you have a retirement fund, lobby them to take their money out of fossil fuels and put in in renewables.

    4) Lobby your government to agree to international cooperation (treaties) that cap fossil fuel emissions, with progressively lower caps each year.

    5) Lobby your university to institute renewable energy research programs, which are woefully scarce in the United States.

    6) Lobby your state and local government to reform building codes to make energy conservation and renewable energy (solar water heaters) a priority.

    7) As others have noted, explain the problem to people at every opportunity and when you see the media do a bad job of covering the topic, be sure to let them know about it. Be sure to tell people about the solutions to the problems, not just about the problem.

    8) Tropical deforestation is the main non-fossil fuel use contribution to increased CO2 emissions. Much of this is due to export agriculture trade policies – so make it a priority to help out developing Third World countries who take steps to preserve their forests (how about free renewable energy technology?)

    The bottom line is that global cooperation is an absolute necessity when it comes to both monitoring the climate system and switching from fossil fuels to renewables.

  36. Timothy Chase:

    David B. Benson (#181) wrote:

    So I think it fair to say that Britian’s and Norway’s heavy rains are more likely to occur with climate change just as the heat around the Mediterranean Sea is more likely to occur with climate change.

    I have noticed the Gulf Stream moving Northeast recently. Part of what seems to be happening is that as the Arctic Ice Cap melts and the northern latitudes warm, the Gulf Stream goes farther north before it descends. If this is the case, then one would expect more evaporation and moisture to be carried north – and presumably in the direction of Great Britain. Additionally, I remember running across material that far north regions may actually experience more rain.

    If one looks at the paths of tropical storms, as they move north, they tend to drop more rain in that region. But by the time they get up there, I believe the wind tends to be much less of a problem. They are actually projecting something along these lines with hurricanes – which are coldcore by the time they reach that area.

    Incidently, the increased moisture in the subarctic region will be bad news as far as the thawing permafrost goes – as it tends to release more methane when conditions are wet. I believe the moisture encourages the growth of bacteria responsible for organic decay. Drier seasons tend not to be as great a problem.

  37. David B. Benson:

    Re #185: Ike Solem — Yes, by all means!

    I think it important to have a goal: I suggest 315 ppm of atmospheric carbon dioxide by the year 2050. I chose this goal by noting that this was the level in 1957-8 when modern continuous measurements began, and before the great run-up in fossil fuel consumption of the last 50 years. It also largely agrees with the highest atmospheric carbon dioxide levels of the Eemian.

    Assume that fossil fuels consumption and deforestration continue to put 7 billion tonnes of carbon into the atmosphere. There is an excess of about 300 billion tonnes of carbon in the atmospheric carbon dioxide. Then sequestering 15 billion tonnes of carbon per year will meet the goal by the year 2050.

    NETL hopes (expects?) to lower the cost of sequestration to $10 per tonne quite soon, i.e., 2008. If this is possible, then meeting the goal requires $150 billion per year. Which implies a carbon tax of $22 per tonne of fossil carbon, if everybody bears an equal portion of the burden…

  38. Stephen Berg:

    A nice refutation of TGGWS:

  39. Steve Bloom:

    This already-unique reduction in Arctic sea ice levels is starting to look a little scary. It’s too early to say that this is the tipping point, but at the same time it’s probably what the tipping point will look like when it happens. See here for the complete satellite-era record. Note that these anomalies are developed via a slightly different metric than the one used by the NSIDC, but the differences are small. AFAICT NSIDC doesn’t produce similar graphics.

  40. Doug Lofland:

    Hello all,

    I have two questions;

    1. Has anyone noticed what has been happening in the Arctic this summer. I have been watching it daily on

    and the sea ice extent seems to be shrinking way ahead of any other year I can find info for. In fact, I made a crude area measurement, and believe that in the last couple of days, the sea ice has shrunk to less than the end of season (early September) for the extreme years of 2005 and 2006. The melt season has at least another six weeks to go. Is this the albedo “flip” that Hansen talks about in his May 2007 paper?

    The government “ice” sites seem very quiet right now. If I am reading the site correctly, should this milestone not be the headlines?

    2. If there was a large discharge of melt water from Greenland during the melt season, how long would it take to affect sea levels to the south, like the SE USA and the Bahamas? I have read of the balancing of new ice forming and adding the mass back in the winter, but could there be temporary “bumps” in the sea level in places before that happens? Last year in Eleuthera (Bahamas)had some very high tides in September, that came up 15cm over anything seen before (over the bulkhead, flooding the grounds), and there were no nearby storms to account for it. This year we will photograph and measure the events, if they repeat. Similar things have happened in S. Florida, and some say it is really the ground sinking. That gave comfort.

    I am new to this site, and I want to say to everyone that you are doing a great job of trying to get the truth out there, whatever that may be. I appreciate the un-biased open attitude here.

  41. Joe:

    TGGWS on our Govt/Public broadcaster makes me kind of ashamed – the Howard Gov’t is one of the worst in the world on so many issues!

  42. cce:

    This is off topic, but I’m trying to identify the most up-to-date land/ocean temperature reconstructions for the northern hemisphere. The ones shown in AR4 are a bit redundant. As I understand it, Mann et al 2003 is the most up-to-date “Hockey Stick.” Moberg 2005 would be another good one to use. Are there any others that are robust, but at the same time, indepedent of one another? I’m interested in the last 1000 years (for the MWP), but I also want to concentrate on the last 400 years as it relates to Lean’s TSI data, so that would potentially open up more reconstructions. This is for a presentation I’m doing, and I don’t want squiggly line overload.

    [Response: You can find them all at NOAA’s paleoclimatology website, under ‘climate reconstructions’. Some of the reconstructions share common data, but others (e.g. Mann and Jones vs Briffa et al) use entirely or nearly independent data from each other. – mike]

  43. Alex Nichols:

    #174 #184
    I’m not aware that there’s evidence of a link between the precise track of the jet stream and global warming, but there does seem to be a link with intensity of rainfall and flooding events in Northern Europe over the past decade.

    There’s a paper coming out on Wednesday in “Nature” by Dr Peter Stott of the Hadley Centre. This deals with the links between extreme rainfall patterns in the northern mid-latitudes and anthropogenic global warming.

    The contents are currently embargoed, but it’s mentioned in this report in today’s “Independent”:

  44. SteveF:

    Nir Shaviv has written a response to Lockwood’s paper. An excerpt:

    L & F assume (like many others before) that there should be a one-to-one correspondence between the temperature variations and solar activity. However, there are two important effects which should be considered and which arise because of the climate’s heat capacity (predominantly the oceans). First, the response to short term variations in the radiative forcings are damped. This explains why the temperature variations in sync with the 11-year solar cycle are small (but they are present at the level which one expects from the observed cloud cover variations… about 0.1°C). Second, there is a lag between the response and the forcing. Typically, one expects lags which depend on the time scale of the variations. The 11-year solar cycle gives rise to a 2 year lag in the 0.1°C observed temperature variations. Similarly, the response to the 20th century warming should be delayed by typically a decade. Climatologists know this very well (the IPCC report, for example, include simulation results for the many decades long response to a “step function” in the forcing, and climatologists talk about “global warming commitment” that even if the CO2 would stabilize, or even decrease, we should expect to see the “committed warming”, e.g., Science 307), but L & F are not climatologists, they are solar physicists, so they may not have grasped this point to the extent that they should have.

    Incidentally, this is not unlike a very well-known effect from everyday life. Even though the maximum radiation from the Sun is received near noon time, the maximum daily temperatures are obtained a few hours later in the afternoon. If we were to correlate the falling radiation between say noon and 3 pm (or between June 21 and July-August), to the increasing temperature over the same period, we would conclude that solar radiation causes cooling! This is exactly what L & F are doing. They are ignoring the fact that over the 20th century, solar activity increased tremendously (see the third figure below). So, even though the 2001 maximum is weaker than the 1990 maximum, we are still paying for the extra heat absorbed over several decades, from the middle of the 20th century.

    [Response: This is just grasping at straws. The response to a mid century rise will peak around 10 years afterwards and then slowly asymptote to a new level. There is no way that it will continue to accelarate 5 decades later. – gavin]

  45. Luke:

    Re 190 some examples of sea level distributions are shown at

  46. Reddog:

    Ok, its mid-July. Where are all the huricanes in the Atlantic? Some activity in the Pacific but no Katrinas
    on the look out. Its warm, so what’s wrong?

    [Response: You do understand that July is historically fairly quiet, don’t you? The overwhelming majority of Atlantic Tropical Cyclones and Hurricanes have historically taken place between August and October. Only once we’re well into August will we start to get an idea of how active a season we’re likely to have. – mike]

  47. Barton Paul Levenson:

    [[A metacomment: without wishing to cast aspersions on anyone contributing here, I’m generally suspicious of claims that population growth is the key problem we face; they are often associated with considerable ignorance about what is actually happening to global and regional populations (e.g. the common and simply incorrect statements that global population is growing exponentially), and with attempts to blame the poor for problems largely caused by the rich.]]

    The exponent has been decreasing with time, but population very much is growing exponentially.

  48. Nick Gotts:

    Re #195 [The exponent has been decreasing with time, but population very much is growing exponentially.]

    All the definitions I can find on the web, aside from some which just give the entirely subjective “extremely fast growth” (for a sample just put “define:exponential growth” into Google) specify that in exponential growth the proportional rate of change remains the same. The proportional rate of global population growth rose fairly steadily for a long period up to around 1970 (Johansen, A. and D. Sornette. 2001. Finite-Time Singularity in the Dynamics of the World Population, Economic and Financial Indices. Physica A 294(3-4):465-502) – or a few years earlier according to UNFPA’s “State of World Population 2007” (, and has been declining fairly steadily since then. Since somewhat before 2000, the absolute annual surplus of births over deaths has also been declining, if UN estimatesa re accurate. By what definition is that time course of growth exponential?

  49. SteveF:

    Gavin said:

    “This is just grasping at straws. The response to a mid century rise will peak around 10 years afterwards and then slowly asymptote to a new level. There is no way that it will continue to accelarate 5 decades later.”

    I agree. Shaviv’s response strikes me as a particularly fine example of special pleading.

  50. J.C.H: