William D. Nordhaus, Sterling Professor of Economics at Yale University, wrote an interesting rebuttal to global warming skeptics in the recent issue of The New York Review of Books. Obviously peeved that his research has been misused by those who argue warming isn’t really happening, Nordhaus gives a blow by blow account of how the skeptics are wrong.
Nordhaus writes that the arguments of warming skeptics can be summed up by a January 2012 editorial in The Wall Street Journal written by a group of scientists called “No Need to Panic About Global Warming.” The article says “the globe is not warming, that dissident voices are being suppressed, and that delaying policies to slow climate change for fifty years will have no serious economic or environment consequences.” To counter this, Nordhaus argues that these scientists, some of which are at top universities, offer “incorrect or misleading answers.” He believes this is particularly dangerous given these public wranglings “muddy the waters” at a critical time.
Here are excerpts from the lengthier argument Nordhaus makes to unravels their claims:
He says the first claim is that the “planet is not warming,” and, in fact, there hasn’t really been any warming for the past 10 years.
Take a look at the chart above. On this, Nordhaus writes: “It is easy to get lost in the tiniest details here. Most people will benefit from stepping back and looking at the record of actual temperature measurements. The figure below shows data from 1880 to 2011 on global mean temperature averaged from three different sources. We do not need any complicated statistical analysis to see that temperatures are rising, and furthermore that they are higher in the last decade than they were in earlier decades.” It’s perhaps the near-term variations that have thrown some scientists off. Within historical bands, there is “volatility,” much like the stock market. However, the overall trends still point up and up.
A second claim is that warming is smaller than the models have predicted, meaning that scientists are exagerating things. Nordbaus unravels the mystery of how climate models actually work:
“The standard approach is to perform an experiment in which (case 1) modelers put the changes in CO2 concentrations and other climate influences in a climate model and estimate the resulting temperature path, and then (case 2) modelers calculate what would happen in the counterfactual situation where the only changes were due to natural sources, for example, the sun and volcanoes, with no human-induced changes. They then compare the actual temperature increases of the model predictions for all sources (case 1) with the predictions for natural sources alone (case 2).”
He then says many models have been run showing that there’s no way nature alone could be responsible for the changes: “A good example is the analysis described in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Several modelers ran both cases 1 and 2 described above—one including human-induced changes and one with only natural sources. This experiment showed that the projections of climate models are consistent with recorded temperature trends over recent decades only if human impacts are included. The divergent trend is especially pronounced after 1980. By 2005, calculations using natural sources alone underpredict the actual temperature increases by about 0.7 degrees Centigrade, while the calculations including human sources track the actual temperature trend very closely.”
The third claim made by the skeptics splits hairs somewhat. Some skeptics argue that CO2 isn’t really a pollutant because it’s not toxic to humans and other life. In fact, many plants and some animals could even benefit from higher levels of CO2. Nordhaus says this may be interesting rhetorically, but under U.S. law CO2 fits the standard definition of a pollutant – a “negative externality.”
“The US Clean Air Act defined an air pollutant as ‘any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive…substance or matter which is emitted into or otherwise enters the ambient air.’ In a 2007 decision on this question, the Supreme Court ruled clearly on the question: ‘Carbon dioxide, methane, nitrous oxide, and hydrofluorocarbons are without a doubt ‘physical [and] chemical…substance[s] which [are] emitted into…the ambient air.’ …Greenhouse gases fit well within the Clean Air Act’s capacious definition of ‘air pollutant.’”
Plus, most agree that the few benefits for some species will be outweighed by the damages to many. Excess, man-made CO2 in the atmosphere is expected to lead to “sea-level rise, more intense hurricanes, losses of species and ecosystems, acidification of the oceans, as well as threats to the natural and cultural heritage of the planet.”
The fourth claim: scientists who are skeptical about climate change are living in fear for their “professional and personal livelihoods.” There isn’t any scientific freedom anymore; it’s like were living in the Soviet Union under Stalin. He says this is hogwash, largely because the most prominent scientists are found at MIT, Princeton, the University of Cambridge, and other leading universities, so they clearly haven’t been penalized.
“I can speak personally for the lively debate about climate change policy. There are controversies about many details of climate science and economics. While some claim that skeptics cannot get their papers published, working papers and the Internet are open to all. I believe the opposite of what the sixteen claim to be true: dissident voices and new theories are encouraged because they are critical to sharpening our analysis. The idea that climate science and economics are being suppressed by a modern Lysenkoism is pure fiction.”
Another claim: Climate scientists are benefitting too much from the hub-bub on the climate. He says all the scientists participating in the complex UN process do so on a voluntary basis, which may or may not help their careers given academic promotions – and tenure – are based on publications in scientific journals, not voluntary contributions.
“The skeptics’ account also misunderstands the incentives in academic research. IPCC authors are not paid. Scientists who serve on panels of the National Academy of Science do so without monetary compensation for their time and are subject to close scrutiny for conflicts of interest. Academic advancement occurs primarily from publication of original research and contributions to the advancement of knowledge, not from supporting ‘popular’ views. Indeed, academics have often been subject to harsh political attacks when their views clashed with current political or religious teachings.”
Furthermore, this may be a smoke screen by those who are actually financing research that creates dangerous doubt: “In fact, the argument about the venality of the academy is largely a diversion. The big money in climate change involves firms, industries, and individuals who worry that their economic interests will be harmed by policies to slow climate change.”
Nordhaus adds that the economic stakes are high for many polluting industries: “Expenditures on all energy goods and services are close to $1,000 billion. Restrictions on CO2 emissions large enough to bend downward the temperature curve from its current trajectory to a maximum of 2 or 3 degrees Centigrade would have large economic effects on many businesses. Scientists, citizens, and our leaders will need to be extremely vigilant to prevent pollution of the scientific process by the merchants of doubt.”
Lastly, he seems annoyed by the misuse of his own research, which is characterized as supporting the argument that there’s no economic basis for climate change action.
“The authors summarize my results incorrectly. My research shows that there are indeed substantial net benefits from acting now rather than waiting fifty years. A look at Table 5-1 in my study A Question of Balance (2008) shows that the cost of waiting fifty years to begin reducing CO2 emissions is $2.3 trillion in 2005 prices. If we bring that number to today’s economy and prices, the loss from waiting is $4.1 trillion. Wars have been started over smaller sums.”
His analysis shows that waiting will only add expense to the shifts that need to occur. “Waiting is not only economically costly, but will also make the transition much more costly when it eventually takes place. Current economic studies also suggest that the most efficient policy is to raise the cost of CO2 emissions substantially, either through cap-and-trade or carbon taxes, to provide appropriate incentives for businesses and households to move to low-carbon activities.”
While he agrees that there are still major uncertainties, why delay on acting on global warming and roll the dice? “Policies implemented today serve as a hedge against unsuspected future dangers that suddenly emerge to threaten our economies or environment. So, if anything, the uncertainties would point to a more rather than less forceful policy—and one starting sooner rather than later—to slow climate change.”
Furthermore, don’t listen to the skeptics who argue that systematic changes to regulations will have catastrophic effects on the economy: “The claim that cap-and-trade legislation or carbon taxes would be ruinous or disastrous to our societies does not stand up to serious economic analysis. We need to approach the issues with a cool head and a warm heart. And with respect for sound logic and good science.”
Read Nordhaus’ full analysis in The New York Review of Books.
In related news, check out a worrying article in The New York Times explaining how U.S. forests aren’t holding up well in a warming climate (already), which is a major problem given trees are a key carbon sink that also help mitigate temperature rise.
Also, explore ASLA’s comprehensive resources on climate change mitigation and adaptation.
Image credit: Why the Global Warming Skeptics Are Wrong / NY Review of Books
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