John Kerry, the U.S. special envoy for climate change, on Friday described fossil fuel subsidies as the “definition of insanity,” denouncing measures taken by governments that artificially lower the price of coal, oil or gas.

Speaking at the United Nations climate summit, where negotiators for nearly 200 nations are trying to seek agreement on a deal that averts the worst effects of climate change, Mr. Kerry called for rapidly phasing out the subsidies. But he defended new language in a draft of an agreement that appears to have watered down a push to curb fossil fuels.

A version released early Friday called on countries to accelerate “the phaseout of unabated coal power and of inefficient subsidies for fossil fuels.” The addition of the words unabated and inefficient was seen by some environmental groups as a loophole that would allow subsidies to continue.

But Mr. Kerry argued that the wording “must stay” in the final agreement because commercial technology to capture and store carbon dioxide emissions could be developed in the future. He said that “knowing what the evidence is” about how sharply global emissions needed to be cut, countries cannot rule out the use of new technologies.

He spoke forcefully about ending fossil fuel subsidies broadly. The U.N. Development Program recently calculated that the world spends $423 billion each year to subsidize oil, gas and coal, about four times the amount needed to help poor countries address climate change.

“That’s a definition of insanity,” Mr. Kerry said, adding that underwriting oil, gas and coal allowed governments “to feed the problem we’re here to cure. It doesn’t make sense.”

Build Back Better will go a long way to off-set the economic issues of phasing out fossil fuels.

After months of grassroots advocacy and high-stakes negotiations, the House passed the Build Back Better Act on November 19. With over 130 different investments in climate and environmental justice and a improvements to the social safety net, Build Back Better is a transformative step towards a more equitable and livable world. Now it’s headed to the Senate — and your senators need to hear why you support the bill!