Joe Biden finally turned up the heat on climate change .

At his final presidential debate Thursday night, the Democratic nominee leaned into the issue on which polls show hes most handily outmatching President Donald Trump , a fossil fuel hard-liner who has stubbornly clung to conspiracies and pseudoscience in the face of mounting climate disasters.

Global warming is an existential threat to humanity, Biden said. We have a moral obligation to deal with it.

Trump deployed a familiar playbook. Citing a narrow metric of greenhouse gas decline, he claimed the United States made significant progress on climate change during a first term in which emissions ticked upward and industry-friendly regulators swept away even modest rules to curb long-term heating. The president insisted that exiting the nonbinding Paris climate accord somehow put the country in a better position to pressure other major polluters to decarbonize. And he flung around bogus numbers about the cost of Bidens popular plan to expand the manufacturing of electric vehicles and eliminate emissions from the electricity sector by 2035.

We have done a wonderful job environmentally, Trump said. And we havent destroyed our industries.

Biden hit back, keeping the focus on the economic opportunity of his proposal to spend $2 trillion over four years on renewable energy, electric vehicle charging stations and clean infrastructure.

This plan has been endorsed by every major environmental group and every labor group, the former vice president said. Labor.