Even among the grim daily toll of pandemic deaths and job losses, the most fateful numbers in the news last week probably came from a huge study carried out by a team of scientists at the World Climate Research Programme. It wove together the warming that has been observed so far, the latest understanding of feedback effects from clouds and other systems, and the record of the climate in the deep past to conclude that doubling the amount of carbon in the atmosphere (which, at current rates, will occur toward the middle of the century) will raise the average surface temperature on Earth between 2.5 and 4 degrees Celsius.
By Bill McKibben. New Yorker. July 29, 2020.