A landmark 2015 study published in the journal Nature concluded that an average local temperature of 55 degrees Fahrenheit is economically optimal, especially for agricultural productivity, but that economic productivity lessens as temperatures rise. The study’s authors said that the damage caused by anthropogenic climate change had been significantly underestimated.

Not coincidentally, wealthy countries like the United States, France, China, and Japan fall in that temperature range. But a half-century’s worth of data, the authors said, demonstrate that wealthy countries are nearly as vulnerable to a warmer world as poorer countries. And countries with hotter climates, which tend to be poorer, will be even harder hit by climate change.

A stunning 77 percent of countries will be poorer in 2100 if fossil fuel use continues on its historic trajectory, the study found.

More recently, a team of climate and Earth scientists and economists concluded that the economic risks of climate change have been grossly underestimating or omitting many of the most serious consequences, in part because there is no precedent in human history for a world in which we are warming the climate far faster than natural events ever have.

The New York Times is keeping tabs, noting that the present regime is reversing nearly 100 environmental rules. It has “weakened Obama-era limits on planet-warming carbon dioxide emissions from power plants and from cars and trucks,” and rolled back many more rules.

Unless nations around the world adhere, at the very least, to reductions in greenhouse gas emissions as pledged in the Paris Climate Agreement, the economic costs of climate change will soon come into sharper focus.

A 2019 study by federal Environmental Protection Agency predicted an annual cost for unchecked climate change of hundreds of billions of dollars per year by the end of this century. The E.P.A. study saw “water shortages, crippled infrastructure, and polluted air that shortens lives,” among other damages.

However, cutting greenhouse gas emissions and adapting to a warming planet would sharply cut that annual cost the study found.

The illustration below depicts specific climate events and the devastating economic consequences of wildfires and extreme weather events.