Thursday, February 15, 2007

Skepticism and Climate Change

To the informed reader, it will come as no surprise that much debate surrounding climate change centers of scientific uncertainty of future events. The na├»ve reaction to uncertainty, originally developed by the skeptics of ancient Greece, holds that since reality is unknown and unknowable*, attempting to make scientifically informed decisions is futile. While little of their “dogmatic doubt”† lives on, the term skeptic survives today. Contemporary skeptics doubt until proven certain. Depending on how much evidence one requires for certainty, those of an overly skeptical disposition can resemble their intellectual forefathers in apprehension toward nascent scientific consensus. This is not say skeptics are apprehensive toward science generally. To the contrary, most either come from scientific backgrounds or are admiring onlookers. Given their prejudice for doubt, it is unsurprising, albeit disappointing, how critical and dismissive many skeptics have been over environmental issues, particularly climate change. Skeptics, like all serious commentators, acknowledge the scientific consensus that the earth is warming and that human activities are partially responsible. However, because the future consequences of climate change are uncertain and regularly exaggerated, they oppose or are critical of remedial policy. However, inaction due to skepticism is itself a tacit choice, as I show below, one more at odds with science than sensible climate change policies. Using skepticism to justify complacency reveals a willful ignorance or misinterpretation of evidence rather than genuine uncertainty.

Climate change skeptics contend that we do not have enough evidence to authorize significant policy changes. In taking a position of ignorance, they assume 1) that we do have enough evidence to justify not making significant changes and 2) that current policies are optimal, such that adopting policies targeted at mitigating climate change could only cause harm.

On the first count, climate scientists easily resolve the issue by putting error bars around informed predictions. Current scientific predictions do not rule out catastrophic climate change in the near future, but neither do they claim it inevitable. Similarly, beach house owners cannot predict with any certainty that a hurricane will or will not hit their home on any given year. As uncertainty does not prevent them buying insurance, nor should uncertainty regarding climate change prevent sensible policy choices. Certainly there is no evidence to suggest that complete inaction is justified.

Even if one is skeptical in spite of the evidence, is there good cause to categorically oppose policies that remediate climate change? Many policies could have positive effects besides reducing green house gas emissions. For example, investment in green technology research may reduce greenhouse gases while promoting overall efficiency. Furthermore, as Thomas Friedman in particular has argued, the US, China, and others do no favors to countries like Iran by continuing to import large quantities of oil. In Iran, oil revenues are used to fund a populist state that redistributes money to its burgeoning population, not to mention nuclear proliferation. Consequently, many grow fat on state support without producing anything of value or investing in non-petroleum sectors. In the long run, this may lead to economic and political instability, evidenced by the poor condition of most resource rich economies (Canada and Norway are notable exceptions).

While there will be external benefits to climate change policy, there is little evidence that the costs will be burdensome. Polluters historically exaggerate the cost of halting pollution, as evidenced by the case of sulfur dioxide emissions. In his book The Undercover Economist, Tim Harmon shows that prior to a pollution permit auction, companies and the EPA estimated that reducing sulfur dioxide emissions would cost $250-700 per ton. However, “when the EPA conducted the auction in 1993, very few polluters made high bids…By 1996, permit prices had fallen to $70/ton.” Because real money is at stake, auctions force companies to tell the truth. I suspect that we are seeing the same pattern again - companies and politicians in their pay embellish the cost of reducing greenhouse gas emissions. Currently, carbon credits in the EU and US sell for far less than $20/ton. Since the average world citizen emits approximately 4.4 tons/year, reducing carbon emissions to zero could conceivably cost less than $100 per person. I doubt it would actually be this cheap, because price would likely rise as emissions approached zero, but it does suggest that significant greenhouse gas reductions could be made at costs far lower than groups like the American Enterprise Institute would have you believe.

The upshot is that the best scientific, economic, and political evidence only occasionally informs policy choices. Belief to the contrary is itself unwarranted by the evidence, and therefore fear of any change is irrational. Skeptics and others, like the secretary of the Department of Energy, respond by invoking the law of unintended consequences to justify complacency. However, the consequences surrounding current policies (e.g. that oil imports could induce political instability and/or spur nuclear proliferation in countries like Iran) are likely as uncertain as those of many proposed policies. The conservative position that resists change tacitly favors current uncertainty over future uncertainty, a position that would need to be substantiated if it is to be believed.

From the contemporary skeptical attitude, useful in provoking scientific inquiry, it does not follow that no policy should be enacted to mitigate climate change. The complacent view fails to acknowledge the current evidence and places an unwarranted faith in the status quo. It stands to reason that such a perspective can only be maintained either out of ignorance or ideology.

* One does wonder how they knew this to be true.
† From Bertrand Russell’s The History of Western Philosophy