Why any estimate of the cost of climate change will be flawed

A new working paper puts the damage far higher. Diego Känzig of Northwestern University and Adrien Bilal of Harvard University use past changes in temperatures caused by volcanic eruptions, as well as El Niño, a years-long increase in heat released by the Pacific Ocean, to model the impact of a warmer planet. Employing long-term data on global economic growth and average annual temperature, they find that an additional 1°C of warming will lead to a 12% fall in GDP. A climate-change scenario with more than 3°C of warming would be, according to their estimates, an equivalent blow to fighting a permanent war.