- A rise of 7 degrees Fahrenheit, or about 4 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 dire forecast as part of an argument to combat climate change. Just the opposite: The analysis assumes the planet’s fate is already sealed.