December 11 , 2009
Should Obama Fight Global Warming?
Obama is going to Copenhagen and will announce that the US plans to cut emissions almost 20% over the next 10 years. That is a huge reduction. Before we commit to such a dramatic course of action, I would like more scientific certainty about the issue. At present we don't have it
The issue of global warming, both from a scientific and public policy perspective, is one that I find fascinating. It is also a field that is, and has been for some time, highly politicized. By that I mean that some sciences have no political implications, i.e. there is no such thing as "conservative" physics or "liberal" chemistry; it is just science based on the scientific method. However, anthropogenic global warming (AGW) is highly political.
To understand where someone stands on the issue, the most important thing to know is not their level of scientific training, but their political bias. I am one of the few people I know who are otherwise reliably liberal on most issues, but remain agnostic on how serious this issue is going forward. If the issue of AGW did not have huge public policy implications, then this scientific dispute could be ignored by the rest of us. But the cost of inaction, if AGW is going to be catastrophic, or the wasted resources, if AGW is not really an imminent danger and we act anyway, make it imperative that the scientists be both forthright and fully transparent as we address this complex issue.
Just recently, there was a huge hacking of the email database of the Hadley Center in UK, where many of the leading AGW supporters are based.
Communications among a key group of very important climate scientists going back years have entered the public realm.
Skeptics have seized on many of these emails, claiming they confirm many of their worst fears about the whole process. The scientists at the heart of this leak claim that everything is being taken out of context and there is no smoking gun of deception.
You can look at the emails for yourself, but at a minimum they do show scientists behaving badly, and not exactly interested in an above-board search for the truth. One guy confesses to homicidal intent toward a critic and another expresses joy over the death of an opponent. There is also advice given on how to hide data and avoid FOIA requests and how to corrupt the process of peer review to silence critics. Another scientist admits that it is a "travesty" that the last 15 years of basically flat global temperatures cannot be explained.
One of the main reasons I am skeptical of AGW is that it has not really been fully developed as a scientific theory. A theory should be a full and complete explanation of all the available data, it should make testable predictions that it passes, it should be subject to experimental verification, the experiments should be reproducible, and the theory should be falsifiable. AGW does not really qualify. The basic argument for AGW is actually rather complex but I will summarize it as follows:
1. Carbon dioxide is a known greenhouse gas.
2. Temperatures have risen in the last hundred years, with the warmest year being 1998.
3. Burning of fossil fuels is raising carbon dioxide concentrations from 280 ppm to 380 currently.
4. The rise in CO2 has caused the rise in global temperatures observed since 1975.
5. We can make good/reliable predictions about how much CO2 will rise in the next hundred years, and how much warming such a rise will produce.
6. Carbon dioxide concentrations will rise to about 850 ppm in next hundred years unless major public policy changes are undertaken.
7. We can make good/reliable predictions about what the effects on the biosphere and human civilization and sea levels will be as a result of predicted warming 50-100 years from now.
8. We are reasonably certain that action must be taken now to bring emissions down sharply if we wish to avoid catastrophic changes, and that waiting 10 or 20 or 30 years is too dangerous.
9. We are reasonably certain that there is no technological fix (cheaper green energy, geo-engineering) that could be implemented 30 or 50 years from now thereby allowing us to avoid spending large sums on emission reductions now.
10. We can reasonably conclude that there are few if any tangible benefits of higher CO2 concentrations, and they are clearly outweighed by the costs, not only for humanity but also for the environment and agriculture.
11.We accept that there are tradeoffs and opportunity costs, and that reduction in emissions growth will have some impact on economic prosperity, but that price is worth it for the benefits, both in the First World, and in the Third World (noting that many Third World countries have immediate human needs that are not being met).
12.Natural variation cannot explain the warming trend of the last hundred years. We know this as tree ring data reliably shows that the Earth has not been this warm in the last thousand years, and even the "Medieval Warm Period" was not as warm as current (this is the finding of one of the scientists whose emails were hacked, Michael Mann). There was some "natural" warming in the19th and early 20th century, e.g. the last time the Thames froze over was1810, but the late 20th century warming is off the charts. We cannot say for certain, but we do think we are warmer now than at any time in the Holocene.
Why I have such trouble with AGW is that although the first three items in the list above are true, the rest are greatly debatable. Michael Mann for example has not had his study reproduced, and has refused to release the underlying raw data on which he built his "hockey stick" graph. This is not proper practice in science. On such a vital question, he should produce everything and let others attempt to rip it to shreds; that's how the scientific process is supposed to work. There is also the more troubling scientific question as to whether tree rings mostly from North America are reliable enough to calculate historical global temps to a certainty of less than 1 degree centigrade. Tree rings really only tell you about land temps during daytime summers, and don't provide above ocean temps, nighttime or winter temps. In fact, his method has not been independently validated as a way to proxy global temps reliably.
For item 6, the IPCC makes a whole set of assumptions about future population growth, economic growth, and fossil fuel use. But so far, even in this decade, IPCC numbers were predicting much more rapid growth of CO2 concentrations than we are seeing. And many critics have complained that the IPCC baseline scenario overestimates population growth by a billion (compared with UN projections), overstates economic growth, and neglects the effects that falling renewable energy prices and rising oil and gas prices in the next few decades will have on energy use mix.
Finally, our ability to predict the amount of warming a given amount of CO2 will produce is highly debatable. "All models are wrong, but some are useful" is an adage in science, but the AGW group seems to think they really can model the Earth's atmosphere in an extremely reliable way, such that the effect of a slight bump in the concentration of a trace gas can be accurately simulated. Models are not evidence and they are not data; they are hypothesis generating, not hypothesis proving. The AGW group cannot explain why, if their models are in fact highly reliable, they don't agree with each other, why they don't release their underlying codes and algorithms to peer review, and most importantly, why they can't explain 15 years of static temperatures (a best fit curve of global temps based on satellite data for the last 15 years is essentially flat, and actually shows a downward trend if you start after the El Nino of `98). Now one can argue that critics of AGW are cherry-picking their time frame, but the fact is that the models made a prediction that we should have steadily rising temps, and while a year or two may fluctuate, a 15-year span is a long time for a model that claims its output is highly reliable. Critics claim the models run "hot", that they predict far more warming than will really happen. To get a 5 degree rise in global temps in next century, that is 0.5 degree per decade. That's a huge increase and we should be seeing it, but we aren't. Critics claim that the models are making fundamental errors in the feedback loops of AGW.
The models all predict positive feedback due to water vapor increasing in the air as CO2 rises and generates mild warming. But critics claim that the feedback is more likely neutral or negative, in which case the models are vastly overstating the problem.
The reality is that we don't know what the right answer is in terms of feedback. And without knowing that, the models are not useful in terms of public policy.
Obama is going to Copenhagen and will announce that the US plans to cut emissions almost 20% over the next 10 years. That is a huge reduction. Before we commit to such a dramatic course of action, I would like more scientific certainty about the issue. At present we don't have it.
Comments can reach me at Nali@socal.rr.com.
