Influential studies have predicted that moderate climate change,up to 3 or 4 degrees Fahrenheit,will not be very damaging to the United States as a whole and will bring some benefits.1 Underlying the argument that climate change will not be very damaging to the U.S.economy is the contention that vulnerable organizations,firms and households will take steps to adapt. This assumption is based partly on the fact that the United States is rich in technology, economic resources, competent organizations and educated people,all of which combine to create a high capacity to adapt. More fundamentally, the contention rests on the observation that the United States spans a wide variety of climatic conditions to which households and enterprises have adapted successfully in the past.According to a recent review,“The literature indicates that U.S. society can on the whole adapt with either net gains or some costs if warming occurs at the lower end of the projected range of magnitude, assuming no change in climate variability and generally making optimistic assumptions about adaptation.”2
These are key assumptions.The perception that damages will be limited has been a significant factor in the conclusion reached by the U.S.government that it was not in the national interest to join in the Kyoto Protocol agreement to reduce carbon emissions because the benefits in damages averted would be small relative to the costs incurred in mitigating GHG emissions in the U.S. to the extent called for in the Protocol. Furthermore, refusal by the United States, the world’s richest country and largest cumulative emitter of greenhouse gases, to ratify the Kyoto Protocol discouraged other countries from joining or implementing an international agreement to limit emissions.Consequently,assumptions regarding adaptation in the U.S.have had broad policy repercussions.
Are these assumptions justified?