Climate change's highest cost: Overheated employees too miserable to work

The costs of lower labor productivity under soaring temperatures could reach as much as $221 billion a year in the United States by 2090, making it the largest category of potential economic damages from climate change. That's according to the National Climate Assessment released by the US Global Change Research Program last week. As temperatures rise, worker output slows and cognitive performance declines, with a dramatic drop-off around 28 C (82 F), says Reed Walker, an economist focused on climate issues at the University of California, Berkeley. Scientists have long recognized that extreme temperatures can reduce productivity, as well as lowering lifetime earnings, widening wealth disparities, inciting violence, and increasing suicides and deaths (see "Death will be one of the highest economic costs of climate change"). But the report estimates the total US cost in lost productivity based on projected temperature increases in the decades ahead, says Brian O'Neill, director of research at the University of Denver's Pardee Center for International Futures and a coauthor of the report.