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Has Pacific Northwest snowpack declined? Yes.

Filed under: — eric @ 20 March 2007

There has been a bit of a flap here at the University of Washington over the state of the snowpack in United States Pacific Northwest region. The Seattle city mayor, Greg Nickels (a well known advocate for city-based CO2 reduction initiatives) wrote in an Op-Ed piece in the Seattle Times that

The average snowpack in the Cascades has declined 50 percent since 1950 and will be cut in half again in 30 years if we don’t start addressing the problems of climate change now. That snow not only provides our drinking water, it powers the hydroelectric dams that keep our lights on.

The number “50 percent decline” apparently comes from a statement in an Oregon State University report in 2004 signed by many Northwest Scientists. This is not actually the best estimate for average snowpack decline, according to published work by Phil Mote, of Climate Impacts Group at the University of Washington. Mote reviewed the Oregon report back in 2004 and pointed out that the 50% figure was erroneous. Mote’s 2003 paper in Geophysical Research Letters, highlighted in Science a few years ago, cited losses “as great as 60%” in some locations. Subsequent work (Mote et al., 2005) attempted to quantify change in total snowpack for the Cascades, and arrived at 15-30% for the period 1950-1997. This remains the best estimate, even when including the time period up to the present. Furthermore, this number represents measurements at many different elevations. If high elevation stations are excluded, the declines are generally larger, as would be expected if the chief culprit is increasing temperature, rather than declining snowfall.

So why the fuss? Well, the media can’t seem to get enough when there is apparent controversy over something. Both the local and national media were thus quick to jump on the “story” when another UW staff member, Mark Albright, sought to correct the 50% number in a series of emails to the Mayor’s office, among other places. Unfortunately, Albright didn’t simply provide the corrected information, but set up a web site entitled “The Myth of the Vanishing Cascade Mountain Snowpack”, with the very clear message that snowpack has not declined at all. Beyond the appearance of a controversy, this makes for a good newspaper story because it appears to cast doubt on Mote’s credibility. This is rather important given that Mote is Washington’s “State Climatologist” and is also the lead author on the chapter on the cryosphere in the upcoming IPCC Fourth Assessment report.

So has Pacific Northwest snowpack declined? Emphatically yes. I say “emphatically yes” for three reasons. First, because Albright illustrates the supposed lack of a trend by comparing specific periods (e.g. 1940-1949 vs. 1997-2006), in which snowpack has increased in some locations. This is not very informative, because both the spatial and temporal variability is large, and any question of decline can only be correctly addressed using all the data together, and over a statistically significant time period (30 years or more would be preferred). According to a summary statement prepared by Dennis Hartman to try to clarify the situation for the media and government, the decline is quite evident when the analysis is done correctly. (Hartmann is currently Chair of the Atmospheric Sciences Department at the University of Washington).

Second, “yes”, because lost in the media focus on controversy over the exact number is the fact that even a 15% decline would be huge. You can get this smaller number by starting in 1940 rather than 1950. This isn’t really justified because low elevations are substantially undersampled before 1945. Using a starting point of 1950 gives you about 30%. Either way, these are big numbers, and represent anything but a trivial change for water resource planners, backcountry skiers, and fisherman (not to mention fish). (For those readers that might wish to look at the data themselves, the State Climatologist’s Office has a rather nifty mapping and trend-analysis tool, here: http://www.climate.washington.edu/trendanalysis).

Third, “emphatically” because the snowpack will very likely continue to decline in the future. In his summary statement, Hartmann notes that “temperatures in the … Cascades will increase in the future as a result of global warming … and it is expected that this, by itself, should result in further decreases of snow … particularly at lower elevations.” Hartmann points out that it is less certain how precipitation will change in the future, and this could conceivably balance some or all of the increased spring time snow melt due to increasing temperatures. However, this is a pretty weak statement. It generally takes a very large increase in snowfall to offset small changes in temperature. Furthermore, precipitation is highly seasonal in this region, and an overall increase in temperature will, at a minimum, cause earlier snowmelt, even in the unlikely event that annually averaged total snowpack remains the same. This means less available water in summer, when fish, farmers, and hydroelectric dams most need it.


173 Responses to “Has Pacific Northwest snowpack declined? Yes.”

  1. 51
    Dave Rado says:

    Re. #44 David, how representative is Klaus of Czech opinion? Are there a lot of influential people in the Czech Republic who think like him, or is do most Czechs realise he’s two prawns short of a barbeque?

  2. 52

    In Los Angeles, we fight traffic, air quality, asthma, global warming, gas prices, oil depletion, road rage…….

    all because there is a conflict of interest at the county level that keeps our roads in gridlock.

    http://trafficbulldog.org is a commuter advocacy group committed to solving our transportation crisis through 1.3 people per car.

    And when that happens, we will get more snow pack in the Sierras.

    Please join the conversation.

  3. 53
    Glen Fergus says:

    #20 “… people should realize that this snowpack decline is not just isolated to the Pacific NW. The “snowpack reservoir” is absolutely essential to nearly all of western North America.”

    … and to Australia’s huge Murray – Darling river basin, now at extreme low-flows after the lightest snowpack year on record in our mountains; data here. Snowpack decline is a global issue, with global consequences.

    #40 Columbia Ice Field

    It’s happening so fast that you can just about watch it melt in real-time, here.

  4. 54
    James says:

    Re #36: [Thus, to maintain the water balance, more streamflow is expected in the winter and less in the summer. And then you can ask yourself, when do humans consume the most amount of water?]

    It might be a good idea to think about other than immediate human needs, too. For most of the western US, most precipitation comes in the winter, and falls as snow in higher elevations. This gradually melts during the summer: in high snowpack years, it’s not unusual to be stepping through remmnants of drifts well into July or even August at the higher elevations. This gradual melting allows the water to soak into the soil, replenishing groundwater & keeping the soil moisture up.

    Now if the snowpack melts earlier, the soil might dry out before plants have a chance to complete their reproductive cycles, and so the vegetation might eventually die. Plants shade the soil, and their roots hold it in place. Without the vegetation, the soil gets hotter, accelerating evaporation. When precipitation falls as rain instead of snow, the soil erodes, and now the rain falls on bare rock where it immediately runs off instead of gradually soaking in. You wind up with mountain range that’s desert, except during the frequent flash floods.

  5. 55
    Paul M says:

    The next decade is going to prove to be an interesting one with the issues of global warming and energy.

    Wasn’t there a time before automobiles that there was a crisis because of all the horse manure being created because horses were used for transportation? My point is that man is clever enough to make a change, but waits until the last minute to do so. Let’s hope someone invents something soon. In the meantime, pull up a chair and watch the metaphorical train wreck happen before our eyes. Many, many times in history man has existed in deplorable conditions, and the global climate crisis will just be another chapter in our history. Why didn’t the people of pompeii get out of town? Because they couldn’t, and so shall it be with this climate disaster.

  6. 56
    D,D. Trent says:

    For those who need a basic primer on glaciers, retreating glaciers on several continents, climate change in SW Australia, the temperature record for the past 1000 years, and the later arrival of winter snows and earlier melting in the western U.S., and other factors that are touched upon in the Q & A excahanges in the comments above, I would sugggest reading the chapter, Glaciation and Long Term Climate Change, that appears in the 5th edition of Geology and the Environment by Pipkin, Trent, Hazlett and Bierman, Brooks/Cole publisher. The 5th edition has just been printed. It is written for freshman-level, liberal-arts college students and hopefully will be intelligible to those whose comments clearly show a lack of understanding of basic science.

  7. 57
    James Annan says:

    #50,

    Certainly over 100 years our actions could have a significant influence over climate change. I’m just pointing out that the Mayor of Seattle’s comment contained an obvious error that suggests a limited understanding of the realities of climate change – unless, horrors, he is well-informed but chose to be deliberately misleading in order to defend his policy of spending taxpayers’ money on carbon offsets.

  8. 58
    Hank Roberts says:

    It’s so hard to tax people who haven’t been born yet, even for their own good.

  9. 59
    Johnno says:

    As it happens I live close to a rope tow ski field at about 1300m which hasn’t operated for a couple of years due to lack of snow. And my snarky comment #2 is truthful because coal fired electricity is being used to boost declining hydro. In this case total precipitation seems to be declining as temperature increases here in Tasmania. Since my trick knee is no longer up to skiing I can put up with warmer and wetter weather but what we’re getting so far is warmer and drier.

  10. 60
    outeast says:

    David (post 44),

    Just wait till his book comes out:)

    Paul (also in Prague)

  11. 61
    C. W. Magee says:

    What effect does land use change (e.g. logging) have on snowpack accumulation and/or longevity?

  12. 62
    Ray Ladbury says:

    James Annan (#45) and Paul M. (#55): I’ve never liked the “helpless observer” theory. Our actions can certainly make things worse (e.g. by bringing closer the day where we release natural stores of CO2 and CH4 as a feedback to our own emissions). They can also make things better by slowing growth in energy demand, diversifying energy resources and giving us longer to develop technologies that mitigate climate change and also help us better to deal with its consequences. To say that we do not control our futures is as pernicious as saying there is no climate change–both attitudes foster complacency, and complacency is never a good strategy when civilization is threatened.

  13. 63
    Dick Veldkamp says:

    Re #55

    [Wasn’t there a time before automobiles that there was a crisis because of all the horse manure being created because horses were used for transportation? My point is that man is clever enough to make a change, but waits until the last minute to do so.]

    The fact that the invention of the automobile prevented a horse manure crisis in 1900 proves exactly nothing about whether the next environmental crisis can be averted by technology. You just can’t be sure that some nifty invention will save you. In fact the sheer size of the CO2 problem makes it quite unlikely that there will be a simple technical solution.

    The reasonable course is to be prudent and limit emissions now. If we do find a technofix, great. But let’s not count on it. It’s like driving off a hill in a car where the brakes don’t work. Never mind, let’s hit the gas anyway! Human ingenuity will certainly find a solution before we hit that brick wall down below, won’t it?

  14. 64

    Re: Comment 9, where Ray says:

    “When one seeks to base an argument on ceteris paribus (all things being equal), it’s a good idea to think it through and make sure the ceteris are in fact paribus.”

    My understanding is that the Latin phrase ceteris paribus means “(with) the rest (being) equal.” The ceteris is the same word (different case ending) as cetera in et cetera (“and the rest [of the things in the list]”).

    The basic Latin words are:
    ceterus, cetera, ceterum, an adjective or noun meaning “the other, the rest.”
    par, paris, a noun or adjective meaning “equal, like.”

    Of course, the idea is a very important one for isolating and then identifying causation. My layman’s idea of experimentation is that it applies the idea of looking at one variable while holding the rest of the factors steady. I would imagine that that is as difficult to do in the climate sciences as it is in my field of interest, history.

    Further, I am intrigued by some other similarities between History and the Climate Sciences. They both look mainly at the past, but employ timeless studies (psychology and economics; physics and chemistry, for example) to understand that past. Experts in both fields sometimes use what they have learned about the past to explain current activities and then, sometimes, make predictions about the future.

    Likewise, the conclusions of the two sciences stir up support and opposition from philosophical combatants who rightly or wrongly cite those two specialized sciences. For example, in the field of History, questions such as — What was the cause of the rise of Nazism? — bring Leftists and Rights into conflict beyond the strictly scientific question.

  15. 65
    matt bullard says:

    Re #61 – “What effect does land use change (e.g. logging) have on snowpack accumulation and/or longevity?” I believe there have been some actual attempts to increase logging in some areas of Colorado as a means to increase runoff. I think this is based on two trains of thought – less vegetation that will use the water in the evapotranspiration process as well as less vegetation to hold/shade the snowpack in place longer into the spring. If my memory serves, test plots showed that this did increase runoff in certain streams, but I am not sure of the ecological consequences of this practice. Based on my set of values, I am highly skeptical and would generally oppose such practices that would artificially increase runoff for human consumption. Based on what has been said about runoff in this thread, I would venture an educated guess that this practice would also increase the chances of flooding and erosion…

  16. 66
    Ray Ladbury says:

    Re 64: I stand corrected in my Latin and will paint the corrected version 100 times all around the palace in red paint (a vague reference to an obscure scene in Monty Python’s Life of Bryan).
    The controversies in history are probably a little more difficult to resolve than those in science. Even when you have documentary evidence, it may be hard to glean the intent of the author when he/she wrote it.
    In science, what constitutes evidence and how much you can trust it is usually a bit more agreed upon, at least within a particular discipline. The oddity in the case of climate change is that contrarians and cranks have been able to ally themselves with entities outside the field who have very deep pockets. This has allowed them to obfuscate the science. There really is no controversy to speak of within the scientific community as to whether climate is changing (It definitely is) or what is largely responsible for causing it (anthropogenic activity). There is more controversy over what will be the consequences–but we are dealing with a chaotic system, and the consequences cannot be predicted with 100% accuracy. Consequently, there is also some disagreement about how forcefully we should respond to this threat. Even Richard Lindzen seems to be in agreement that humans are influencing climate. He merely believes that this chaotic system will somehow restore itself to equilibrium no matter how hard we push it away from its current relative stability. The climate record–and the dynamics of chaotic systems–would seem to disagree with Dr. Lindzen.

  17. 67
    P. Lewis says:

    Re #66 (Ray Ladbury)

    In science, what constitutes evidence and how much you can trust it is usually a bit more agreed upon, at least within a particular discipline. The oddity in the case of climate change is that contrarians and cranks have been able to ally themselves with entities outside the field who have very deep pockets. This has allowed them to obfuscate the science. There really is no controversy to speak of within the scientific community…

    I don’t wish to divert attention too much from snowpack changes, but you only have to witness what happened (in the UK at least) with the history of asbestos and deep pockets. Science facts hold little sway at times, despite how much you tell people what they don’t want to know.

  18. 68
    yartrebo says:

    Re #65:

    Clearing forests to increase runoff is downright stupid, and even the proponents of that plan are probably just looking at the money they can make selling the wood. It will increase local runoff, but it will also add massive amounts of silt to the river, which will fill reservoirs and thus reduce their capacity to hold water. Forest removal will also reduce humidity and thus rainfall downwind, which would be the Great Plains. The Great Plains don’t exactly have a surplus of rainfall as it is.

    Let us not even talk of the ecological stupidity of that plan or all the CO2 that will be released (many times the CO2 stored in the tree trunks).

  19. 69
    Ken Coffman says:

    I think you guys are missing a great data point. Here in northern Washington State, 12,500 years ago, we were covered with a sheet of ice almost a mile thick. So, simply pick that as your starting point. Now it is indisputable, the ice/snow pack has decreased by, oh what the heck, let’s just round it off to 100%. We’ll have to get very creative now to blame the loss of the first 99.999% of that ice/snow pack on human-contributed causes of global warming. But, with your models and super computers, I’m sure you can figure it out.
    – Just trying to help.

  20. 70
    Clifford Mass says:

    I think there is much more to this than the author is suggesting. The trends used in the Mote paper are deceiving… because they are contaminated by interdecadal variability..namely the PDO–the Pacific Decadal Oscillation–which had a maximum (meaning more snow) peaking around 1950 and a minimum in the 90s. Thus, the trend line calculated by Mote suggests a large decrease in snow pack that is not necessarily connected with global warming. In fact, the snowpack has been steady or increasing during the past 20-30 years…a period in which the global warming signal should be largest and in which the PDO signal is of the same sign. Global climate change appears to be increasing precipitation and this may be resulting in overall snowpack holding even if temperatures are warming. Furthermore, the PDO may switch to a snowier regime as would be expected from its typical periodicity. Thus, we may well see the Cascade snowpack being maintained for the next decade or so, until the global warming signal is overwhelming.
    Regarding the 50% decrease issue. That number was allowed to stand for over a year and was repeated in other web pages and in a 2004 report to the Governor of Oregon. The meteorological profession must be more careful in the future to insure we are effectively communicating our knowledge and particularly our uncertainties.
    Finally, talking to Phil Mote and Dennis Hartmann (chair, atmos sci) and others…it appears that many of us believe that a decrease of 10-15% due to human influence is not unreasonable. This value is within interannual variability and can easily be dealt with by society. 50% loss is a very different matter indeed.

    [Response: Cliff. Thanks for dropping in. I agree with you of course that there is a big difference betwen 50% and 10-15%. But in terms of public policy there is an even bigger difference between “no snowpack decline” and “10-15% decrease due to human influence.” That’s the reason for this post — to make it clear that the evidence does NOT suppor the position that human influence (a.k.a. “global warming”) is a non-issue for considerations of future water supply (not to mention skiing) here in this region. And I don’t think anyone has said that the Cascade snowpack will necessarily decline over the next decade. As you know well, the variability on decadal timescales is quite large, and we may even see an increase (as we did in the last few years). No doubt, if that happens, we’ll hear all sorts of talk about how “the IPCC had it wrong, global warming is a myth, etc.”. That’ll be a shame, because it will be dead wrong, but will provide lots of political cover for folks that don’t want to take future water resources issues seriously.

    Having said all that, I should note that 1) your argument that the last 20-30 years is a “a period in which the global warming signal should be largest” should be interpreteted with caution. The PNW doesn’t care about the global mean! If I plot 1977-2006 April SWE, most stations show more snowfall. But many stations show cooling, not warming, over the same period. So there is certainly not the contradiction you imply there is. 2) Your comments on the PDO will also be misleading to many of our readers, because you are implying that there is some predictability in the PDO. But the power spectrum doesn’t show periodicity, and one cannot use it to make any sort of predictions. We might get a “run” of 10 years in the positive phase, but then again we might not. I think that Don Percival (also here at UW) has shown this quite clearly. So I have no confidence that the snowpack will either decline nor grow in the next decade. What I have more confidence in is the long term decline. (Though I am sure we both agree that Mayor Nickel’s specific prediction that we’ll only be at 25% of the “original” snowpack levels by 2047 is not particularly believable, and I probably should have stated this in my post. –eric]

  21. 71
    Steve Bloom says:

    Re #66: Youa culpa, Ray! Now all you have to do is learn to conjugate without a sword being held to your throat. :)

  22. 72

    [[I think you guys are missing a great data point. Here in northern Washington State, 12,500 years ago, we were covered with a sheet of ice almost a mile thick. So, simply pick that as your starting point. Now it is indisputable, the ice/snow pack has decreased by, oh what the heck, let’s just round it off to 100%. We’ll have to get very creative now to blame the loss of the first 99.999% of that ice/snow pack on human-contributed causes of global warming. But, with your models and super computers, I’m sure you can figure it out.]]

    And if we start from 1607, we can show that North America is a British Colony.

    The implication that we’re warming because we’re coming out of an ice age is wrong no matter how many times you hear it from Rush Limbaugh. We passed the peak of the interglacial 8,000 years ago and the Earth should now be cooling.

  23. 73
    Harold Ford says:

    RE: 30. I’ve had this preconceived idea that CO2 might not make it up into the upper atmosphere due to it being heavier than most common atmospheric gases. The rational being that in a fire CO2 hangs around on the ground (if you crawl around inside a burning house you choke, if you stand you get burned) possibly due to its density. I was also thinking that CO2 migrates toward the equator due to prevailing winds (no rotation of the Earth considered). If that is not the case, why is it not the case. In other words, how is it that CO2 is making it to the polar regions, it should be stuck in the tropics being devoured by plants at least by that train of thought, did I miss the boat?

    [Response: Nice idea, but the gravitational effects on individual molecules in the atmosphere are tiny compared to the forces of all the molecules colliding with each other. So at normal densities and pressures (up to at least the mesosphere) all of the gases are well-mixed – with the exception of water vapour because it condenses as a function of temperature. – gavin]

    [Just to clarify this further, CO2 is actually not well mixed on very short timescales. This is what allows CO2 to remain near the ground in a house for example, or to be higher at night in a forest (when trees are respiring) than outside the forest. Think about it — does the CO2 in burning house stay there forever? Of course not. It eventually esapces the house and mixes with the outside atmosphere. On timescales of months to years, which is all that matters for climate, it is well mixed throughout the troposphere.–eric]

    [Response: Another perspective on this: CO2 is heavier than air, and if there weren’t mixing it would congregate in a layer near the ground. with an average depth of about 3 meters. Most of us would have to stand on a step ladder to breath, at least near sea level. –raypierre]

  24. 74
    Ray Ladbury says:

    Harold, Even if there were no updrafts, etc. CO2 would still make it to the upper atmosphere, if only because the Maxwellian destribution of energies would always have some molecules in the tail that would be energetic enough to rise. Moreover, the density of CO2 is not so high (44 g/mole vs 32 g/mole for O2) that there would be complete segregation.
    Most important to remember, though is that Earth’s atmosphere is turbulent. Winds lift dust (much higher density than CO2) and water droplets to great heights. I’m not sure why you think it would move preferentially toward the equator.

  25. 75
    Greg Clark says:

    Great Blog! I’m creating a solutions oriented site focusing on allowing everyone to commit and share their sustainable goals. If you interested in joining, please visit http://www.sgoals.net/

  26. 76
    Mark A. York says:

    RE#69 I referred Ken Coffman an electrical engineer here from another site. He wanted to read my novel but when he found out I was on the other side, this one where the facts are, he was more interested in ad hominems than learning. Just another Imhofe.

  27. 77
    Harold Ford says:

    RE 74 ty Ray. In response to what I meant about the winds, the sun and the rotation of the Earth give an over all average pattern the movement of the air. The sun for instance causing a majority of the rise of air currents in the tropics causing a general pole to equator movement of air. CO2 being heavier than N2 and O2, with no major updrafts, it would simply lie near the bottom of the atmosphere while the average movement of the air would increase CO2s density at the equator. A major updraft could cause it to rise, but then it would fall back faster than O2 or N2 which would be carried further North and South than CO2. I see your point on the turbulence and take it that gusts would carry CO2 high into the atmosphere but there still should be some stratification of CO2. N2 has 28g/mol while O2 has 32g/mol a bare 4g difference yet still one needs/desires more oxygen while climbing Mt Everest. CO2 is much heavier in that respect (44g/mol as noted in #74) and so there should be even larger differences in its distribution than even O2 and N2. The main question would be, is CO2 evenly distributed at lower altitudes, if so then why, if not then why.

  28. 78
    Ken Coffman says:

    “We passed the peak of the interglacial 8,000 years ago and the Earth should now be cooling.”

    Now you’re scaring me, Barton Paul. You’re saying there are impending cooling forces that are completely out of human influence or control? Since I’m far more afraid of cooling than heating, you really have my attention now. What are we going to do to survive when the ice caps beigin growing again? Should we really push for more warming now to delay or reduce the impact of the cooling? I suppose we could use nuclear power plants to stay warm. How about drilling heat pipes to our hot core? We’d better get busy now. I work for a company that does green power and support for the more efficient LED lighting, what are you guys doing? I don’t think there is any time to waste.

  29. 79
    Hank Roberts says:

    What do you think, Mark, is he interested in learning about the science?
    I’ll trust your judgment whether this is just going to be trolling.

  30. 80
    Aaron Lewis says:

    Remember also, that areas that were shaded snow pack under dense forest inthe lower Cascades 50 or 80 years ago, have been logged, and turned into roads, malls, parking lots, and housing. Suburbia does not have snow pack. Thus, less snow pack, particularly at low altitudes.

    More auto traffic means more soot and dust which deposits on snow and increases early spring melting. Thus, there is less snow pack.

    The problem is not with the precipitation, the problem is that the snow is melting before it can be measured as “snow pack.”

  31. 81
    Ken Coffman says:

    Great, now Mark York is checking in. Excellent. Hi Mark. You can see I’ve followed your advice and I’m reading up on the science on this site and trying to stretch my limited intellect to follow the issues and absorb the wisdom. I definitely have an open mind on these topics. Convection, radiation, energy storage. I can’t wait for the test.

  32. 82
    Ray Ladbury says:

    Re 77: The reason one needs O2 on Everest is because the atmospheric density itself declines, not just O2 decreases. To a first approximation (ideal gas equation) the density (n/V) will decline roughly linearly with pressure (of course temperature also declines, too). No, I don’t know of any rotating system with an energy input where the fluids stay stratified by density.

  33. 83
    Ray Ladbury says:

    Re 69. Somewhere, buried in almost any post is a point trying to find its way out. I believe the point to be found in this point is that different climate drivers are important in different epochs. The deglaciation of the current interglacial is understood to have occurred due to increased insolation. But snow pack was a pretty stable source of water for the duration humans have inhabited the Northwest. That is now changing, and increased insolation cannot be the cause, since the Sun’s output has not significantly increased. Mr. Coffman seems to be implying that the development is not significant, but it is very significant to those living in the Northwest. And perhaps you could attribute it to fluctuations were it not happing at sites all around the globe–the Pacific Northwest, the Alps, Tasmania and New Zealand, the Himmalayas… And indeed it is part of a larger trend–dates of first and last frost are moving closer together–again globally. So, thank you Ken for making that point.

  34. 84
    Ken Coffman says:

    “He wanted to read my novel but when he found out I was on the other side, this one where the facts are, he was more interested in ad hominems than learning. Just another Imhofe.” – Mark York

    Now Mark, please be nice. You accuse me of using ad hominem attacks, but I haven’t. I only said I think you’re a funny guy. And, I suggested, if you apply yourself, you could be like George Soros and do the world some good. That is not name-calling. [edit] And above, I’m an Imhofe. I don’t think these are persuasive elements of effective arguments.

    I apologize if I suggested the wrong role model. I can substitute Al Gore or Bill Joy, if either accurately reflect your ambition. Or, pick your own, I’d be very interested.

  35. 85
    David B. Benson says:

    Re #77: Ken Coffman — The first possible date for a try at a stade (ice sheets) would have been in 20,000 years. Probably this will be missed due to anthropogenic warming. The next try is then 50,000 years from now. Probably this will be missed for the same reason. So even if we do our best to stop warming the globe, the next stade won’t be for 150,000 years.

    I think you are worried about entirely the wrong thing.

  36. 86
    Craig Allen says:

    Re 78: When were we due for the next ice age in the absence of global warming.

    The Wikipedia entry on the Milankovitch cycles is well written and directly addresses this point. (Milankovitch cycles are the cyclic changes to Earths orbit, angle to the sun etc. – over tens of thousands of years – that determine the amount of incoming sunlight and it’s angle to the poles, and which are thought to pace the glacial/interglacial ages.)

    A model of the effect of the Milankovitch cycles on the Earth’s climate described the 2002 paper in science by Berger & Loutre “Climate: An exceptionally long interglacial ahead?”, predicts a possible ice age in 50,000 year time (in the absence of anthropologically enhanced CO2).

  37. 87
    Harold Ford says:

    Re#82 There are systems that stratify but under controlled conditions and not for long, some sort of alcholic beverage. I looked up some things concerning CO2, due to its 44g/mol it tends not to mix and pours like a liquid. But it does eventually mix, somthing about Brownian motion and diffusion, so its possible that it could hang around the source of CO2 emission areas for a period of time before dispersing. diffusion “things move from regions of high concentration to low concentration”. So I guess CO2 cannot be ruled out as the main cause of global warming :?

  38. 88
    Elijah says:

    There is a very interesting article talking about the mantel of the earth being exposed to the ocean. Could the ice be melting due to the earth warming the oceans with its missing Crust? Warmer ocean waters will change weather patterns. Just an interesting look at another aspect or reason why the ice is melting, and what could be causing or contributing to global warming.

    [Response: Uhhh.. No. The sun provides us with roughy 340 Watts/m2 of the earth’s surface. The flux of heat from the earth itself is less than 0.1 W/m2. Not even close to being important! Locally of course, it matters a lot (sitting on top of a volcano for instance). But climate doesn’t care about very localized heat sources.–eric]

  39. 89
    dhogaza says:

    [edit – abuse of other commenters is not welcome.]

  40. 90
    Harold Ford says:

    Re #85: It would seem so but actually I’ve another scenario thought up, though I’m not sure how realistic it is. Methane is considered the runner up in the green house gas gas. I’m not sure that that is the case. There was an article not long ago concerning CO2 causing the ice to move. The problem with it is that CO2 was only found in the later ice ages and not in earlier ones. Back to diffusion, natural gas being very light would diffuse quickly upwards, possibly forming a pure layer of natural gas (due to its high rate of diffusion), and eventually break down, either oxidizing slowly or quickly. If it burned over the polar regions heated CO2 and H2O (a hot acid rain?) could be sucked down on to the polar caps (depending stratosphereic conditions) thus leaving a high concentration of CO2 in the ice as well as heating the air, sort of like a household propane heater using forced air. Might the natural gas only start to form in large quantities on the Earth, showing up in the atmosphere late in the greenhouse game, explaining the CO2 being missing prior to whatever maxim it was found in?

  41. 91
    Wang Dang says:

    Re #66

    Ray, this is a science site, when it comes to Monty Python there is no such thing as a vague reference or obscure scene.

    In fact, the RC comments often remind me of the People’s Front of Judea. Or was it the Judean People’s Front. Or the Popular People’s Front…

  42. 92
    James Annan says:

    #62 (Ray)

    I’m no fan of “helpless observers” but I’m also no fan of gesture politics, and without claiming that science always has the answer I do think that policy decisions should at least have a passing acquaintance with whatever relevant facts are known. If the projected decline in snowpack over the next 30 years is thought likely to have serious effects on water, power, tourism, Yeti or whatever then the Mayor would be well advised to look for real solutions rather than engaging in tokenism.

    FWIW I’m also not keen on such hyperbole as “civilisation is threatened” but I’ll let that pass without comment this time :-)

  43. 93
    The Wonderer says:

    Re: #88: I believe there is something much more sinister at work. I was alerted to this during a bicycle trip through the Canadian Rockies and past the moonscape of Athabasca Glacier last summer. Apparently, Arctic Ice (Arctic Ice Co.) is being shipped to grocery stores across Canada and elsewhere, and sold to thousands of unsuspecting customers, cubed and in plastic bags. Obviously, this is also why Arctic ice is disappearing much faster than Antarctic ice. ;)

  44. 94
    James says:

    Re #78: [Since I’m far more afraid of cooling than heating, you really have my attention now. What are we going to do to survive when the ice caps beigin growing again?]

    Stake a claim on some of the continental shelf uncovered by the lowering sea level :-)

    Seriously, I think it’s been argued that by a standard of total biological productivity, the Earth is actually better off during an Ice Age. Cooler ocean waters are more productive (due to upwelling which replenishes nutrients in the upper layers), areas like the Great Basin & Sahara become savanna instead of desert, the area uncovered by the lowering sea level more than compensates for what’s covered by ice sheets, etc.

  45. 95
    Ron R. says:

    Off topic, sorry. According to this Raw Story article V.P. Cheney may have been personally involved in censoring climate change reports. Seems surprising that the source of the info is supposedly Environment & Energy Daily. Isn’t that M&M’s bastion?

    http://rawstory.com/news/2007/Democrats_focus_on_Cheneys_involvement_in_0321.html

  46. 96

    [[CO2 being heavier than N2 and O2, with no major updrafts, it would simply lie near the bottom of the atmosphere while the average movement of the air would increase CO2s density at the equator. A major updraft could cause it to rise, but then it would fall back faster than O2 or N2 which would be carried further North and South than CO2. I see your point on the turbulence and take it that gusts would carry CO2 high into the atmosphere but there still should be some stratification of CO2.]]

    Your intuition is leading you astray here. CO2 is well mixed throughout the troposphere. You have to drop a theory if it doesn’t match the evidence.

  47. 97

    [[“We passed the peak of the interglacial 8,000 years ago and the Earth should now be cooling.”

    Now you’re scaring me, Barton Paul. You’re saying there are impending cooling forces that are completely out of human influence or control? Since I’m far more afraid of cooling than heating, you really have my attention now. What are we going to do to survive when the ice caps beigin growing again? Should we really push for more warming now to delay or reduce the impact of the cooling? I suppose we could use nuclear power plants to stay warm. How about drilling heat pipes to our hot core? We’d better get busy now. I work for a company that does green power and support for the more efficient LED lighting, what are you guys doing? I don’t think there is any time to waste. ]]

    1. It would take 20,000 to 50,000 years for the next ice age to start, so there is no imminent danger.

    2. Global warming has eliminated the likelihood of another ice age altogether. That was the point of my post. The Earth should be cooling (very gradually), but is warming because we’re pumping so much greenhouse gas into the atmosphere.

  48. 98
    Ray Ladbury says:

    Re 88: Elijah, the energy exchange is too local–and therefore to limited to be having a global effect. I do wonder though whether it might not be a significant source of nutrient upwelling into the more productive shallow depths of the ocean.
    #90 Harold, again, in a turbulent system, things tend not to stratify. Look at Saturn and Jupiter where Hydrogen mixes with methane, etc. Still the release of large amounts methane is a serious concern, as its absorption spectrum makes it a more efficient ghg (per unit mass) than CO2. Moreover, I think you will find that a column of gas with a concentration of CH4 will absorb the same amount of radiation (to 1st order, neglecting screening), whether the methane is in a column or not. The CH4 and CO2 trapped near the poles is largely due to the large amounts of peat in the permafrost.
    Re 92. James Annan, I really do not consider the contention that civilization is threatened by climate change to be hyperbole. You have to remember that civilization is a rather young phenomenon, and I do not think it is a coincidence that civilization’s emergence coincides with a period of exceptional climatic stability that shifted the balance in favor of agriculture and markets/trade over hunter-gatherer economies. Climate change does indeed threaten two mainstays of modern civilization–agriculture and cheap energy.

  49. 99
    Ken Coffman says:

    [edit]

    How does one earn respect around here? Is it IQ? The number of patents your name appears on? The number of books you’ve sold? Measurable success in a technical field? I know, I have to suspend common sense and historical perspective and embrace the conclusions of modeling done by the IPCC. Well, too bad for me, I shall remain willfully retarded in that regard.

    It’s true, I’m poking fun. Seriously though, I believe the current interglacial warming of the Holocene era has enabled the rise of our glorious civilization. We’ve been cold for most of the last 160,000 years. I worry about short growing seasons, susceptibility to disease (have you noticed your body fights off infection by feverish heating?) and other cold-climate-related nastiness (not to mention what the cold weather does to my golf game). So, I wonder who will be in charge of the global thermostat? I’d like to lobby for a few more degrees, not only for my comfort level in the Pacific Northwest, but for alleviating the effects of the coming cooling cycles.

    The earth goes through cycles of many types. It gets warmer and colder. Right now it’s warm and you reap the benefits of that luxury. If we humans have some small influence on climate, then perhaps we should redouble our efforts toward warming. The more sane response to climate change, in my mind, is to adapt. Use our brain power and technology to create new forms of energy and work on using it effectively.

    This is a non sequitur, but a mantra we should recite routinely. Correlation is not causation. Just a thought for the day.

    [Response: Please keep comments substantive. Name calling will just be deleted (as I have above). -gavin]

  50. 100
    Ray Ladbury says:

    Re 99: Ken, several skeptics have earned respect in this forum–at least from most of the participants. They have done so by being knowledgeable about issues, by keeping their comments substantive and by realizing that when an intelligent person devotes 20-30 years of his or her life to studying a subject, their views on that subject are worthy of consideration if not acceptance.
    It is true that correlation is not causation, but correlation plus a well understood physical mechanism makes a much stronger argument for causation.
    You call for development of new technologies to mitigate the effects of climate change. In such a call, you would find many allies in this forum. My own position is that given the magnitudes of the likely changes we will be confronting, and given the difficulty of predicting a chaotic system, anything we can do to slow the onset of these changes and give ourselves more time to adapt represents a wise investment. I’m afraid that I agree that we will not stop climate change. We can make it worse, however, and by extension, I hope we can also make it better.

    This forum represents a valuable resource. I am far from an expert–my field is radiation effects in semiconductors–so I am learning a lot from the time I spend here. I also learn from the skeptics that can present their arguments in a respectful tone. You can contribute more to the discussion by eloquently stating your own position, rather than attacking those of others.


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