by Judith Curry
A new report from the IPCC implies that “climate exceptionalism”, the notion that global warming is a problem like no other, is coming to an end. – Economist
In spite of the spin being put on the WG2 Report by the IPCC spokespersons and other advocates for climate alarmism and mitigation, there is some thoughtful analysis going on, and I’ve selected articles from The Economist and the Atlantic for discussion.
The Economist has an article entitled Climate Change: In the Balance. The article discusses the WG2 Report. Excerpts:
The report describes three different sorts of problem. The first are those in which climate is the dominant influence, so that no human action other than stopping it changing will have an effect. The second are those in which the climate’s influence is modest and where the news is not entirely bad. The third are the ways a changing climate alters which species (both natural and agricultural) thrive where—which from a human perspective can be both good and bad.
Rising sea levels are an example of the first sort of problem. Another example of a problem of the first sort is ocean acidification.
The second sort of problem, in which the climate’s influence is more modest and manageable, includes its effects on health. By and large, the report says, the bad impacts will outweigh the good, but in neither case is climate the dominant influence on mortality or morbidity. Public health and nutrition matter more. Malaria cannot spread if it has been exterminated.
The third category, the way a changing climate alters species’ ranges, is in some ways the most intriguing. To the surprise of a lot of conservationists, for example, global warming does not seem to have caused many extinctions. Roughly half of studies of likely cereal yields over the next ten years forecast an increase, whereas the other half forecast a decline. Forecasts for the 2030s are even more sobering: twice as many predict a fall as a rise.
Dividing up the effects of climate change in this fashion leads to different ideas about how to respond. Defending low-lying cities against a rising sea level is difficult and expensive, and it is impossible to adapt to ocean acidification. These problems would best be dealt with (if at all) by attacking the cause: ie, by cutting carbon-dioxide emissions.
Problems in the second category, however, can be approached in other ways. As the report itself says, “the most effective vulnerability reduction measures for health…are programmes that implement and improve basic public health [like] the provision of clean water.” Such measures would be beneficial even if there were no climate change.
The third category lies somewhere in between. It requires measures that should be undertaken anyway, but need to be tweaked because of the climate. Farmers are always trying out new crop varieties, but increasingly those varieties will have to be drought-resistant. That may mean choosing between different aims, for there is often a trade-off between drought resistance and yield.
This way of looking at the climate is new for both scientists and policymakers. Until now, many of them have thought of the climate as a problem like no other; and best dealt with by trying to stop it (by reducing greenhouse-gas emissions). The new report breaks with this approach. It sees the climate as one problem among many, the severity of which is often determined by its interaction with those other problems. And the right policies frequently try to lessen the burden—to adapt to change, rather than attempting to stop it. In that respect, then, this report marks the end of climate exceptionalism and the beginning of realism.
The Atlantic has an article The UN’s new focus: surviving, not stopping climate change. Excerpts:
But in a 2007 article for Nature, a team of academics gave three reasons for why the “taboo on adaptation” was gradually disappearing:
1. The “timescale mismatch”: Even if world leaders take decisive action to cut emissions (a big “if”), it won’t have an impact on the climate for decades, and greenhouse-gas concentrations will continue to increase in the meantime.
2. The emissions fallacy: People are vulnerable to the climate for reasons other than greenhouse-gas emissions, including factors like socioeconomic inequality and rapid population growth along coasts.
3. The demands of developing countries: While wealthy countries account for most greenhouse-gas emissions, poor countries suffer the most damage from climate change. And these developing countries want the international community to help them become less vulnerable to the extreme climactic events they’re facing now, rather than arguing over emission targets that will theoretically protect them in the future.
The IPCC’s early climate reports in the 1990s barely mentioned climate-change adaptation. But that changed in the panel’s 2001 edition, which noted that “adaptation is a necessary strategy at all scales to complement climate mitigation efforts.” The IPCC spent two pages discussing “adaptation options” in its 2007 study, and this week has devoted more than four chapters to the strategy, including a graph that shows our ability to adapt to climate change in three eras: the present; the near-future we’ve committed ourselves to based on current emissions; and the distant future we still have the capacity to shape.
This shift is a positive development for two reasons. First, adaptation measures are less politicized than mitigation measures. People may not agree on the science of climate change, but uncertainty about the future is no excuse for failing to prepare for the worst. “The dam of orthodoxy is cracking,” Simon Jenkins wrote in The Guardian on Monday. “If Rome is burning, there is no point in endlessly retuning Nero’s fiddle.”
Second, preparing for the worst actually presents major opportunities for the private sector and local governments. In its report this week, the IPCC is indeed calling for action—but not in the form of grand international declarations or promises. “Among the many actors and roles associated with successful adaptation, the evidence increasingly suggests two to be critical to progress; namely those associated with local government and those with the private sector,” the report states. The implicit message: Citizens should stop waiting for world leaders to legislate climate change away—because that can’t be done. Instead, individuals and communities need to show entrepreneurial initiative and figure out how best to survive in an increasingly volatile climate.
The ‘end of climate exceptionalism’ was first articulated (as far as I can tell) in this article by Andrew Lilico.
I find the Economist’s separation of impacts into three categories to be very interesting, although I’m not sure exactly how I carve out categories 2 and 3. Category 1 is the only category where CO2 mitigation in principle makes sense – the timescales of the impacts are slow and long, with unambiguous losers (and no winners). However, our understanding of ocean acidification and its impacts is in its infancy (see this previous post). Anthropogenic sea level rise is an unknown fraction of total global sea level rise (some question that there is evidence of anthropogenic acceleration); more significantly, sea level rise from climate change is only a fraction of the total sea level rise in many vulnerable locations, with geologic subsidence and land use (especially ground water extraction) dominating in many locations.
For CO2 mitigation to make sense given the uncertainties in sea level and acidification impacts, CO2 migration would need to benefit the whole host of potential adverse impacts from extreme weather events, public health, species extinction, etc. Attribution of these adverse impacts to AGW is weak, with both winners and losers, and a large number of confounding factors. The WG2 focus on adaptation measures in concert with other natural and societal factors, on measures that we can implement NOW for benefits that we can receive NOW, whether or not climate variability/change is anthropogenic or natural.
I like this statement from The Atlantic:
First, adaptation measures are less politicized than mitigation measures. People may not agree on the science of climate change, but uncertainty about the future is no excuse for failing to prepare for the worst.
The question then becomes NOT what is causing climate change or how we can prevent it, but rather: How much resilience can we afford? I suspect that Andrew Lilico may be right in that the WG2 report reflects a fundamental change in the climate change debate.
A reminder that the WG3 Report on mitigation is forthcoming. As far as I know, there haven’t been any leaks on this one yet, but I am inferring from some twitter comments that the costs of mitigation may be higher than previous estimated. Stay tuned.
IMO, this is a much healthier and realistic place to be on the public debate regarding climate change and what to do about it.