[The authors of this study framed their results incorrectly, I think, causing many in the media to miscover or ignore the story.]
Scientists led by a former co-chair of the Intergovernmental Panel on Climate Change [warn] that the UN negotiations aimed at tackling climate change are based on substantial underestimates of what it will cost to adapt to its impacts.
The real costs of adaptation are likely to be 2-3 times greater than estimates made by the UN Framework Convention on Climate Change (UNFCCC), say Professor Martin Parry and colleagues in a new report published by the International Institute for Environment and Development [IIED].
And as the IIED reported, the study Assessing the costs of adaptation to climate change: a review of the UNFCCC and other recent estimates concludes costs will be even more when the full range of climate impacts on human activities is considered.
The study finds that the mean “Net present value of climate change impacts” in the A2 scenario is $1240 TRILLION with no adaptation, but “only” $890 trillion with adaptation.
The mean [annual] impacts in 2060 are about $1.5 trillion…. As usual, there is a long right tail, with a small probability of impacts as large as $20 trillion.
Don’t worry folks, it’s only a “small probability” — but that “fat tail” by itself is enough to render all traditional economic analyses useless (see Harvard economist: Climate cost-benefit analyses are “unusually misleading,” warns colleagues “we may be deluding ourselves and others”). Let’s put aside the fact we are on pace to exceed the A2 scenario (which is “only” about 850 ppm atmospheric concentrations of CO2 in 2100): See U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm “¦ the worst-case IPCC scenario trajectories (or even worse) are being realised” “” 1000 ppm. For this country, the A2 scenario means 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year.
But here’s the key point the media and the authors failed to convey. In the “aggressive abatement” case (450 ppm), the mean “Net present value [NPV] of climate change impacts” is only $410 trillion — or $275 trillion with adaptation. So stabilizing at 450 ppm reduces NPV impacts by $615 to $830 trillion. But the abatement NPV cost is only $110 trillion — a 6-to-1 savings or better.
Bizarrely, the authors never point this out directly. They are adaptation experts, so rather than focusing on the immense economic benefits of preventing catastrophic global warming in the first place, they offer up this secondary conclusion as their primary finding: