The Republican candidate on Monday promoted his plan to purportedly save the government $100 billion over eight years. It involves cutting all federal spending on climate change programs, both domestic and international.

“We’re going to put America first,” Trump said at a Michigan rally. “That includes canceling billions in climate change spending for the United Nations, a number Hillary wants to increase, and instead use that money to provide for American infrastructure including clean water, clean air, and safety.”

As Bloomberg BNA reports, Trump didn’t give a precise tally for how he got to $100 billion:

[The] campaign press office said that the figure combined an estimate of what the Obama administration had spent on climate-related programs, the amount of U.S. contributions to an international climate fund that Trump would cancel, and a calculation of what Trump believes would be savings to the economy if Obama’s and Clinton’s climate policies were reversed.

That math, however, doesn’t work out: According to a 2014 report from the White House’s Council of Economic Advisers, a global temperature increase of just 3 degrees C would cost the United States 1 percent of GDP, or $150 billion a year, by damaging public health and infrastructure and battling sea-level rise, stronger storms, declining crop yields, and increased drought and wildfires.

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