While the estimates differ, each shows an economic impact of less than a few percentage points for a few degrees of warming. The consensus, apart from two counterbalancing outliers, is that today’s warming of 2.2 degrees Fahrenheit has reduced GDP by less than 0.5%. That is trivial, considering real GDP has grown by more than 800% since 1950. If warming reaches 4.5 degrees—about what the United Nation’s climate panel projects for 2100 under plausible scenarios for future global emissions—the consensus reduction amounts to less than 2%. In other words, if the average annual GDP growth rate is 1.5% for the next 80 years, the economy would grow 232%. A 2% climate-change effect would reduce that growth to 225%. As physicists say, that’s a difference “in the noise.”