Heat Waves: Legal Adaptation to the Most Lethal Climate Disaster (So Far)

Abstract

Globally, the ten warmest years on record have all been since 1998, with the four warmest years occurring since 2014. In the contiguous United States, average annual temperatures are about 1.8°F higher than they were over the period from 1895–2016. This is expected to increase by about 2.5°F before mid-century, regardless of what happens to greenhouse gas levels. If, at the end of this century, greenhouse gas emissions are at the Intergovernmental Panel on Climate Change’s high scenario (termed “RCP 8.5”), average U.S. temperatures could go up by as much as 11.9°F by 2100, with emissions at a middle scenario (RCP 4.5), and temperatures perhaps as little as 2.8°F. This shows that greenhouse gas levels will not make much of a difference to what we experience over the next few decades, but will make a huge difference toward the end of the century. Even if the world meets the goal set at the Paris Climate Conference in 2015 of keeping rises well under 2°C (3.6°F) above pre-industrial levels, which seems increasingly unlikely, the average summer high temperature in the United States is expected to rise from a historical average of 74°F to an average of 81°F by 2100; with high emissions, that could be 91°F.