Firefighters from Brea, Calif., inspect and cut fireline on Aug. 1, 2018, as the Ranch Fire burns near Upper Lake, Calif. A day earlier, it and the River Fire totaled more than 74,000 acres. (Stuart W. Palley/For The Washington Post)

Last month, deep in a 500-page environmental impact statement, the Trump administration made a startling assumption: On its current course, the planet will warm a disastrous seven degrees by the end of this century.

A rise of seven degrees Fahrenheit, or about four degrees Celsius, compared with preindustrial levels would be catastrophic, according to scientists. Many coral reefs would dissolve in increasingly acidic oceans. Parts of Manhattan and Miami would be underwater without costly coastal defenses. Extreme heat waves would routinely smother large parts of the globe.

But the administration did not offer this…