Jean-Marc Jancovici

The Environmental Protection Agency said on Friday that it would eliminate its scientific research arm and begin firing hundreds of chemists, biologists, toxicologists and other scientists, after denying for months that it intended to do so. The move underscores how the Trump administration is forging ahead with efforts to slash the federal work force and dismantle federal agencies after the Supreme Court allowed these plans to proceed while legal challenges unfold. Government scientists have been particular targets of the administration’s large-scale layoffs.

Legal residents of the United States sent to foreign prisons without due process. Students detained after voicing their opinions. Federal judges threatened with impeachment for ruling against the administration’s priorities. In the Opinion video above, Marci Shore, Timothy Snyder and Jason Stanley, all professors at Yale and experts in authoritarianism, explain why America is especially vulnerable to a democratic backsliding — and why they are leaving the United States to take up positions at the University of Toronto.

In the run-up to the November election, conventional analysis suggested that a Trump victory would mean an additional four billion tons of CO2 emissions to the atmosphere by 2030, a total surrender on the climate pledges the country had made under the Paris Agreement and the functional end of the global goals that agreement established among nearly all the world’s nations.

A rule known as the endangerment finding requires the E.P.A. to regulate greenhouse gases. It has proved resilient against earlier attacks.

The American West has gone bone dry, the Great Salt Lake is vanishing and water levels in Lake Mead and Lake Powell, the two great life-giving reservoirs on the Colorado River basin, are declining with alarming speed. Wildfires are incinerating crops in France, Spain, Portugal and Italy, while parts of Britain suffocated last week in temperatures exceeding 100 degrees Fahrenheit.

The rapid collapses of two ice shelves on the Antarctic Peninsula over the past quarter-century were most likely triggered by the arrival of huge plumes of warm, moisture-laden air that created extreme conditions and destabilized the ice, researchers said Thursday.

An analysis of satellite images by The New York Times rebuts claims by Russia that the killing of civilians in Bucha, a suburb of Kyiv, occurred after its soldiers had left the town. When images emerged over the weekend of the bodies of dead civilians lying on the streets of Bucha — some with their hands bound, some with gunshot wounds to the head — Russia’s Ministry of Defense denied responsibility. In a Telegram post on Sunday, the ministry suggested that the bodies had been recently placed on the streets after “all Russian units withdrew completely from Bucha” around March 30.

A chunk of Antarctic ice that was one of the biggest icebergs ever seen has met its end near South Georgia. Scientists will be studying its effects on the ecosystem around the island for some time.

The United Nations secretary general, António Guterres, on Monday issued a blistering critique of the world’s failure to rein in global warming, calling on countries to return every year to review their climate targets — not every five years, as the Paris climate agreement spells out. “Even if the recent pledges were clear and credible — and there are serious questions about some of them — we are still careening towards climate catastrophe,” he said at the opening ceremony of COP26, the U.N. climate summit in Glasgow.

Vingt-trois agences fédérales ont planché sur la question durant plusieurs mois. Le quotidien passe en revue leurs conclusions les plus frappantes suivant les ministères concernés : Two dozen federal agencies flagged the biggest dangers posed by a warming planet. The list spreads across American society....

Dr. Horowitz, who lives in New Orleans, is the author of “Katrina: A History, 1915-2015.”