Mr. Regan informed agency employees that he would leave before the formal end of the Biden term.

© Pete Kiehart for The New York Times

Even in formerly low-risk areas, home insurers are raising premiums and ending coverage. The upheaval could push down home values and reverberate through the economy.

© Paul Ratje for The New York Times

Readers discuss his role in the government shutdown negotiations. Also: Trump austerity; G.O.P.’s future; clean energy; guns and young people.

Jigar Shah and Robinson Meyer discuss how the decarbonization rollout can continue during the second Trump administration.

The promise of deeper emissions cuts will very likely be ignored by the Trump administration, but officials hoped it would send a signal to the world.

© Kim Raff for The New York Times

I had read about how the rapid warming of the Arctic was upending the landscape and its people. Now I’ve seen it.

The president can still do a lot before he leaves the White House.

Every farm, even the scenic ones with red barns and rolling hills, is a kind of environmental crime scene, an echo of whatever wilderness it once replaced.

Readers discuss the British vote on the issue and urge actions in the U.S. Also: Safeguarding our food; taxing cow burps in Denmark; a crossword tale.

Even at my lowest, I have never entirely given up my faith that good people working together can change the world for the better.

Climate purity is a recipe for failure.

Readers discuss what one calls a “boom-or-bust precipitation cycle.” Also: Pete Hegseth’s mother’s accusation; what opera needs; Elon Musk and Mars.

Could one tiny legume save the planet?

Martha Schwartz Partners works around the globe to take on pollution and warming of the planet.

The financing plan, which calls for $300 billion per year in support for developing nations, was immediately assailed as inadequate by a string of delegates.

As he made his final appearance at global gatherings, including at the Group of 20 summit in Brazil, President Biden lobbied for his foreign policy goals even as leaders shifted attention away from him.

China has now passed Europe in its historical contribution to global warming. Rich nations say the country should contribute more climate aid.

Days ahead of the U.N.’s global negotiations on climate change, China and other developing countries said trade restrictions should be part of the talks.

Times foreign correspondents describe what’s at stake for the world, including China, Israel, Ukraine, global trade and climate.

Food production is concentrated in too few countries, many of which face water shortages, the researchers said.

A surge in power use worldwide could make it harder for nations to slash emissions and keep global warming in check.