The Rest of the Story

Finally, the Truth About Global Warming

The Christian Science Monitor sometimes has stories that are written like good, well-researched blog entries, complete with hyperlinks.  Today they have one about climate change.  The author does not really seem to advocate any particular position; rather, he collects bits of information from a variety of sources and puts them together.  That particular style of writing is effective.  I found the article to be rather disturbing, because it is convincing without coming across as preachy or argumentative.  For example:

Global warming: a threat to world security?
posted February 8, 2005, updated 12:00 p.m.
By Tom Regan | csmonitor.com

Last week in England, a group of top scientists, experts and government officials gathered at the behest of Prime Minister Tony Blair to discuss global warming, and the news they heard there was not optimistic. [...]

In early January, Dr. Rajendra Pachauri, the chairman of the official Intergovernmental Panel on Climate Change (IPCC), told an international conference of 114 nations gathered in Mauritius that the world has "already reached [a] level of dangerous concentrations of carbon dioxide in the atmosphere" and called for immediate and "very deep" cuts in the pollution if humanity is to "survive".

The statement was interesting because Dr. Pachauri was put in place in 2001 at the behest of the Bush administration. Oil giant Exxon had asked the Bush administration to replace his predecessor because he was too "aggressive" on the issue.

The blog Daily Kos reported two weeks ago that Pachauri's recent comments were very much a "blow" to the US position, especially since they saw him as a supporter of their "go slow" approach to battling global warming. [...]

Their main point was to show how climate change can become a national security issue.  This is somewhat analogous to my earlier point about how public health can become a national security issue.  In the case of climate change, the problem will stem from mass relocations of people, combined with a rapid decline of available resources. 

Former UN chief Boutros Boutros-Ghali has long said that the next Middle East war will be fought for water, not oil.

Now, I don't consider myself to be an expert on the subject.  I know enough about science in general, though, to be able to tell that the climate change issue is complex, difficult to understand, and easy to misunderstand.  Most pundits appear to take the easy route, and think of it as a single-issue topic.  It is not.  There are at least five questions; they are related, but distinct.  One: Is the Earth warming? Two: Is the warming caused by human activity? Three: If the Earth is warming, will the trend continue?  Four: If the Earth is warming and the trend continues, how serious will the effects be?  Five: Can we alter the course of climate change by altering human activity? 

There is ample evidence to answer the first question.  The Earth is getting warmer.  Science Magazine published an essay, in December 2004, entitled The Scientific Consensus on Climate Change. 

The Scientific Consensus on Climate Change
Naomi Oreskes

Policy-makers and the media, particularly in the United States, frequently assert that climate science is highly uncertain. Some have used this as an argument against adopting strong measures to reduce greenhouse gas emissions. For example, while discussing a major U.S. Environmental Protection Agency report on the risks of climate change, then-EPA administrator Christine Whitman argued, "As [the report] went through review, there was less consensus on the science and conclusions on climate change" (1). Some corporations whose revenues might be adversely affected by controls on carbon dioxide emissions have also alleged major uncertainties in the science (2). Such statements suggest that there might be substantive disagreement in the scientific community about the reality of anthropogenic climate change. This is not the case.

[...] That hypothesis was tested by analyzing 928 abstracts, published in refereed scientific journals between 1993 and 2003, and listed in the ISI database with the keywords "climate change" (9).

The 928 papers were divided into six categories: explicit endorsement of the consensus position, evaluation of impacts, mitigation proposals, methods, paleoclimate analysis, and rejection of the consensus position. Of all the papers, 75% fell into the first three categories, either explicitly or implicitly accepting the consensus view; 25% dealt with methods or paleoclimate, taking no position on current anthropogenic climate change. Remarkably, none of the papers disagreed with the consensus position.

From a "backgrounder" published by The Economist:

Global warming
Feb 8th 2005
From Economist.com

Global temperatures and sea levels seem to be rising, but whether this is mankind's or nature's fault is unclear. Environmentalists point to a build-up of greenhouse gases caused by the burning of fossil fuels, deforestation, dairy farming and other human activities. Whatever the causes, the effects are felt most keenly at the Arctic pole. [...]

Questions Two and Three are more difficult, because the answers are based upon interpretations of a vast quantity of data from a variety of scientific disciplines.   Based upon a cursory, nonexpert review of the reports, I tend to think the answer to the second and third questions is: yes.  The fourth and fifth ones, of course, are the really interesting ones, and are inherently more difficult to answer.  As to the severity, it could range from a serious problem to a catastrophic problem.  From the CSM article:

Also last week, another group of scientists from the British Antarctic Survey (BAS) reported that "a massive Antarctic ice sheet previously assumed to be stable may be starting to disintegrate ..." Such an event could "raise sea levels around the world by more than 16 feet."

That would make the recent tsunami look like a glass of spilt milk. 

Given the findings from the UK meeting (the one Tony Blair called for) and the results of the world's largest environmental modeling study (published in Nature;  720KB PDF of report here), we can see that a range of outcomes is possible.  From a summary of the report:

The figure shows the change in globally averaged surface temperature with time after carbon dioxide values in the atmosphere are doubled. The black lines show the 15 years of phase 3 from 2579 climateprediction.net runs, and the red lines show comparable results from 127 30-year simulations completed by the Hadley Centre on the Met Office's supercomputer.

The illustration is rather small, as presented here; click on it to go to the original.  At first glance, the illustration seems uninformative.  It shows a huge range of possible outcomes.  Each line represents the impact of carbon dioxide accumulation on mean global temperature in one particular scenario.  Since there are so many variables, they had to run the simulation thousands of times.  Reading the original report in Nature doesn't clarify much.  It is written in such a technical manner that only a specialist could have any hope of deciphering it.  That being the case, I could see how someone might glance at the scientific reports pertaining to climate change, and jump to the conclusion that there is too much uncertainty for us to draw any meaningful conclusions. 

So what is the curious nonspecialist to do?  We have data that show a wide range of possible outcomes, varying from awful to really catastrophic.  We have a pile of data that is too complicated for most people to understand, and we have experts who are speaking out on both sides of the issue.  Some feel there isn't much to be alarmed about; others genuinely are worried. 

Generally, when there is a complex issue of great public importance, we turn to the experts to tell us what to think.  But if the experts disagree, then what?  First, try to find out what is causing the disagreement. 

It turns out that much of the disagreement comes from a surprising source: economics.  You see, the predictions of the impact of CO2 are based upon predictions of CO2 output, which, in turn, are based upon predictions of economic growth.  If the economists cannot agree on how much economic growth there will be, it is impossible to form a full consensus on the probable impact of climate change.  This is discussed in the February 4, 2005 issue of The Economist. 

One chief sin is the reliance by IPCC modellers on market-based exchange rates instead of purchasing-power parity, which adjust wealth according to domestic purchasing power—which many economists believe is more accurate. That, says David Henderson, an economist at London’s Westminster Business School, leads to unrealistic projections for economic growth and therefore emissions growth.

Personally, I don't find that to be very reassuring.  What it tells us is that there is disagreement over the future rate of global warming.  So, maybe it will take ten years, maybe twenty, possibly thirty, before serious consequences begin.  A lack of consensus on that point does not change the basic argument: climate change is likely to occur, and when it does, it will be bad. 

Much of the rancor over the climate change issue has to do with economics.  Specifically, would it be worth the investment now, to try to curb CO2 emissions?  The Economistmight be thought of as an authoritative source of information of that issue.  To them, the time frame makes a very big difference.  Obviously, if you invest X dollars now, to get Y payoff in Z years, the value of the investment is going to be related inversely to the size of Z.  The smaller Z is, the better the investment. 

If you are interested enough to have read this far, you may recall that I started out be talking about a different aspect of climate change: it is a matter, not just of economics, but of national security.  That, it would seem, puts things in a different light.  Although economists will disagree about the specifics of various models, at least they all agree on one thing: if the investment gives a good enough return, then it is a good investment.  Matters of national security are not so simple.  Once you introduce that question, things really get murky. 

Some people, apparently, think that a hint of possible "weapons of mass destruction related program activities" justifies spending $200+ billion dollars, and loosing 1,300+ lives.  Yet those same people do not think that a wealth of hard data -- about something as unglamorous as carbon dioxide -- justifies spending much of anything.