The Grand Canyon was carved out by glaciers. What is it now ? Mostly dessert ...
Posted on 03/18/2006 6:04:59 AM PST by beavus
The airing of doubts about global warming that I solicited last week has been remarkable: 169 blog comments (albeit with some repeats) and a number of private emails (including one from a college suitemate and engineering classmate I haven't seen in 18 years). I started the whole discussion because I felt communication on an important scientific issue had broken down, and I figure the best way to make sure we've reconnected the wires is to try and summarize what everyone has been saying. That way, you can correct me if I've misunderstood, misclassified, or just plain missed something. Later, I can take a stab at analyzing the comments and answering some of the requests for further reading, and I hope the discussion will continue from there.
The two most common arguments were:
* Climate has varied naturally long before humans ever arrived on the scene, so it seems likely that the present trends are simply a continuation of that.* The prediction of global warming is just another instance of doomsaying, which has proved so wrong in the past.
[More:]
I've organized the comments into categories. Obviously there is some overlap among them.
I. Warming may not actually be occurring. Most respondents seemed to agree that the global average temperature is rising, but some did not. Their doubts hinged mostly on the reliability of temperature and CO2 reconstructions.
A. This past winter was so cold. Where's the warming?
B. The hockey-stick graph, which suggests the present warming trend is historically anomalous, is flawed. One respondent said it "has been proven false by many papers." Others worried that, at least, it downplays the natural variability in climate.
C. The ice core data, one of the ways used to reconstruct past climate conditions, are dubious. They may not represent the global paleoclimate because they sample only a few locations; they appear to contradict the paleobotanic (leaf stomata) data; and they cannot be meaningfully compared with modern surface temperature readings, because they are distinct data sets.
D. Ground temperature readings are subject to systematic errors such as the urban heat island effect. One respondent went further and complained that the Climatic Research Unit raw temperature data are "kept under wraps," so outside observers cannot verify that selection effects were properly accounted for.
E. Ground temperature readings contradict satellite measurements.
F. Reports of changes in polar climate are anecdotal and could be localized effects.
II. The present warming could be a natural uptick. Respondents pointed out that climate conditions fluctuate because of volcanism, the obliquity cycle, changes in solar output, and internal (chaotic) variability. Why, they asked, do climate scientists attribute all pre-industrial fluctuations to such natural causes and all industrial-age ones to anthropogenic ones? One respondent put it this way: "Every time I read that we have had 'the hottest summer in 100 years' I wonder what caused that hot summer 100 years ago."
A. It could be a rebound from the Little Ice Age or indeed the last Pleistocene glaciation.
B. It correlates "nearly perfectly" with solar output.
C. It could be explained by variations in cloud cover, which alter how much sunlight the planet absorbs. The cloud cover could, in turn, be explained by variations in cosmic ray flux, modulated by solar magnetic cycles.
D. It could be explained by decreases in Earth's magnetic field strength.
E. It could be explained by natural methane sources, ranging from termites to the recently discovered aerobic processes in plants.
F. It could be partly anthropogenic, but the natural variability is larger. A number of respondents argued that it is hubris to suggest that humanity could have such a large effect on the planet. "Many people seem to have a very exaggerated view of how significant we---and our activities---are," one wrote.
III. CO2 emissions cannot explain the warming. This is complementary to the previous item on natural causes, but I broke it out because respondents offered such a variety of hypotheses for why CO2 cannot cause warming.
A. Negative feedbacks stabilize the climate system against the direct effect of added CO2. One respondent wrote: "The Earth's ecosystem is far too robust to be affected by this minor change [in CO2 levels over the past century]."
B. If CO2 drove climate, changes in gas levels should be followed by changes in temperature. Yet paleoclimate data show the opposite: temperature changes first, then the gas levels.
C. In modern times, temperature and CO2 have been only weakly correlated. For instance, there have been long periods of declining temperatures even as CO2 levels have risen. Climate scientists attribute this to masking by aerosol cooling, but their explanation struck many respondents as ad hoc. Also, most human emissions came after 1950, yet the rise in temperature started earlier.
D. High CO2 levels earlier in geologic history (for example, during the late Ordovician) did not correlate with high temperatures.
E. CO2 is a pittance compared to water vapor. By one estimate, it can cause only 0.2% to 0.3% of the warming.
F. The greenhouse effect has "saturated"---further CO2 input does not increase it.
G. No one has done lab experiments to study CO2 absorption.
H. If CO2 causes warming, then the warmed air should rise, reducing air pressure at the surface. That is not observed. The correspondent who raised this objection cited Marcel Leroux's "Mobile Polar Highs" theory.
I. Although CO2 may be a factor, rising levels of this gas are due not to emissions but to reduced uptake by the oceans (perhaps caused by a diminished phytoplankton population).
IV. Climate models are unconvincing. In this category, I put the argument that, whatever the inherent plausibility of anthropogenic global warming, climate scientists have yet to present a solid case. The concerns here revolve around the inability of models to capture the complexity of the climate system.
A. The correlation of CO2 levels with temperature is not causation.
B. Weather forecasting is so unreliable. How could long-term climate forecasting be any better?
C. The range of model predictions is wide, casting doubt on their reliability.
D. Models can't even predict El Nino.
E. Models can't even explain past data. One respondent wrote: "Claiming the models can predict climate is either wishful thinking, ignorance or deceit." Others were more circumspect. One of the few respondents to say what could change their minds wrote: "I'd like to see environmental data from the 1970s fed into today's climate models and the 'predictions' match what actually happened." Another asked whether models can explain climate over geologic time.
F. Models are not proof. They can be used to prove anything. Being non-falsifiable, they are not really science.
G. The burden of proof rests with those claiming anthropogenic warming. Because mitigating climate change would entail huge costs, and because past warming episodes have been natural, it is up to climate scientists to dispel all reasonable doubts---not to climate skeptics to prove them wrong.
V. Warming is a good thing, so we shouldn't try to stop it. The arguments here varied from specific benefits of warming to general reassurances that Earth and its inhabitants have done just fine in earlier periods of warming.
A. It will increase humidity in tropical deserts and improve the lot of high-latitude regions.
B. Higher CO2 levels encourage plant growth, and that's good.
C. Sea level will rise gradually enough that we can readily adapt. The example the respondent gave was beachfront property. Its value will gradually decline as sea levels gradually rise, encouraging a move farther inland over the usual cycle of property investment.
D. Historically, humanity has done better during periods of warmer climate.
E. For most of its history, Earth has been warmer than today. The idea is that global warming is nothing to fear because it merely takes us back to a more natural set of conditions. Animals and plants seemed to do just fine in those periods of warm climate. One respondent wrote: "Our present chilly climate is the aberration when judged on a geological time scale." Over geologic time, the global mean temperature is 22 degrees C, versus today's 15.5 degrees C.
F. It staves off the next glaciation, which we're due for.
G. Claims that global warming has worsened storm damage, or will do so, are overblown. If storm damage seems to have increased, it is simply because more people live in storm-prone regions and their plight is more widely publicized than before.
H. Attempts to stop global warming would do more damage they than avert. Warming might be bad, but it is better than the alternative, be it Kyoto or some other mitigation strategy. The underlying assumption here is that the null strategy---letting the economy adopt non-carbon energy sources as commodity prices dictate, without any explicit reference to global warming---carries the least costs.
VI. Kyoto is useless, or worse. Many of the complaints were specific to the Kyoto Protocol, which sets up a cap-and-trade system for greenhouse gases.
A. It would bankrupt us. One correspondent said Kyoto mandates "a practically unlimited expenditure of effort (and money, naturally)."
B. Even it would not bankrupt us per se, it would divert resources from other, better-established priorities.
C. It would reduce warming by a meager 0.02 degrees C.
D. It exempts developing countries, whose emissions intensity and growth rates are much higher than those of developed countries.
E. People may claim to support it, but their energy-wasting habits belie their true sentiments.
VII. People who argue that human activity causes global warming can't be trusted. Now we get to what seems to be the single biggest complaint: doubts as to the competence or motivation of scientists and others who accept anthropogenic climate change. Many respondents perceive scientists as jumping to conclusions, haughtily dismissing doubters, refusing to take the time to explain things, and adopting absolutist positions. One respondent wrote: "What data would convince me? I don't know if data is the problem as much as needing to perceive an objective voice." Cataloging these complaints has been hard, but here is my attempt.
A. Climate scientists have lost their credibility by making bad calls.
1. They used to predict an imminent ice age.
2. They falsely attributed the ozone hole to CFCs. The respondent who raised this point wrote that the ozone hole was clearly not due to CFCs because it began to recede before CFCs were phased out.
3. They uncritically accepted the hockey-stick graph, which was clearly "fraudulent" from the start.
4. They are guilty of doomsaying, which has been so consistently wrong in the past.
5. They were too quick to connect last year's hurricane season with global warming.
B. Climate scientists behave unscientifically.
1. They ignore contrary data and alternative explanations. Respondents complained that climate scientists are guilty of groupthink. For them to admit they might be wrong would hurt their reputation and funding chances, so they tend to cling to positions with a fervor that the data do not justify. The IPCC was said to seek out evidence that supports its preconceived conclusion. Similarly, people complained that scientific journals do not publish contrary data, presumably because of negative peer reviews by dogmatic climate scientists.
2. They are arrogant. Researchers, wrote one respondent, "go ballistic if anyone voices doubt." Another said: "A person with doubts, or simply unanswered questions, is shut out of the debate. One can only ask questions when it is phrased with unwavering support for warming."
3. They have let themselves get caught up in activists' agendas.
4. They themselves have an activist agenda. Respondents were suspicious that global climate change fits a little too conveniently into a certain environmentalist narrative that holds that humans can do no good (least of all if those humans are Republicans). Moreover, respondents said that if taken at face value, global warming seems to demand Soviet-style government action, which is problematic in its own right and a sign that the hypothesis is ideologically motivated. Because the U.S. is often singled out for its policies, there is a whiff of anti-Americanism, too.
5. They have a financial interest in global warming. Now we're starting to get into more serious accusations that scientists push global warming because it helps them curry favor with granting agencies. One person wrote: "There are no grants available to disprove global warming.... [Researchers] gather at government's teats for monetary nourishment, telling mommy whatever she wants to hear." Kyoto, too, has created vested interests and a strong incentive to "massage data."
C. Activists and journalists have gone overboard.
1. Experts do not, in fact, argue that humanity is the main cause of global warming.
2. The media sensationalizes warming. It focuses on worst-case scenarios and presents tenative research as definitive.
3. Scientific American lost its own credibility on the subject when it printed a one-sided critique of Lomborg's book. One respondent claimed that the magazine "threatened legal action to stifle debate" about Lomborg's book.
So there you have it. Let me know whether you think I've been fair, and I'll try to fix it up.
"I'd like to see environmental data from the 1970s fed into today's climate models and the 'predictions' match what actually happened."
A couple of other respondents here have used this quote. I have the 1970s Newsweak editorial which desperately predicted a rapid global cooling and a slate of things we must do immediately in order to forestall it.
One factor I did NOT find in this litany is one of my favorites: how long have we been taking measurements with such a fine-toothed comb? Especially the satellite based ones? What, 30 years, max? How in the H-E-double-Hockey-Sticks can such a thin cross-section represent anything significant? Especially, how can we even consider ponying-up trillions of dollars over the next few decades in order to prevent something we don't even know is unnatural? Good grief!
"I'd like to see environmental data from the 1970s fed into today's climate models and the 'predictions' match what actually happened."
A couple of other respondents here have used this quote. I have the 1970s Newsweak editorial which desperately predicted a rapid global cooling and a slate of things we must do immediately in order to forestall it.
One factor I did NOT find in this litany is one of my favorites: how long have we been taking measurements with such a fine-toothed comb? Especially the satellite based ones? What, 30 years, max? How in the H-E-double-Hockey-Sticks can such a thin cross-section represent anything significant? Especially, how can we even consider ponying-up trillions of dollars over the next few decades in order to prevent something we don't even know is unnatural? Good grief!
sorry... something in my computer is double-posting my posts lately, since yesterday... anybody got a suggestion?
Yosemite Valley, however, was indeed carved by glaciers.
I have yet to hear from the global-warming wackos why we should be concerned about melting glaciers right now, when a million years ago the entire Yosemite Valley was filled with ice that disappeared before man had learned to tame fire.
I am convinced that "Global Warming" is a plot by leftist termites to undermine capitalism and promote authoritarian socialist government.
-ccm
Global warming is a smoke screen to limit oil drilling and production to keep the price of oil high. We probably have a 2-300 year supply of oil but it's illegal to get at it because of the EPA rules. The consolidation of oil companies closed down a lot of refineries and what is the big excuse now for high prices ? Lack of refinery capacity.
Read later
There is a global warming trend to the extent that real science, not the NYT, not a NASA spokesperson, not Time magazine, can prove from available data that there is a global warming trend. Anything else is a political agenda. But it won't make a lick of difference whether the whole world adopts Kyoto, goes back to a pre-industrial "golden age", adopts central planning, or does whatever the hell it wants. The world isn't going to end. As with any weather patterns, some benefit and some don't. Such is life. Humanity has been dealing with that since prehistoric times, but I think we're a little better equipped for handling these problems now. Maybe some nations in Africa can't, but the reasons for that have nothing to do with technology and everything to do with human nature.
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