I spent July 4 at the ballpark, for a game between the Washington Nationals and the Boston Red Sox. The stadium was supposed to be filled to capacity. But by the game’s middle innings, a huge number of seats — about half, in some sections — were empty, even though the game was tied. In more than 40 years of attending ballgames, I had never seen anything quite like it.What was going on? It was a brutally hot day in Washington, and many people found it too uncomfortable to remain in their seats. So they decided to escape the sun and wander the stadium’s shaded concourses or to leave the ballpark altogether.Washington is often hot in the summer, of course, but the heat wave of the past week has been decidedly abnormal. “For the week through Tuesday, 227 U.S. records were broken for highest temperature for particular days, and another 157 were tied, federal statistics show,” Malcolm Ritter of The Associated Press reported. Burlington, Vt., for example, experienced its highest daily low temperature on record: On Monday, the temperature never fell below 80 degrees.It’s not just the United States, either. “From the normally mild summer climes of Ireland, Scotland and Canada to the scorching Middle East, numerous locations in the Northern Hemisphere have witnessed their hottest weather ever recorded over the past week,” Jason Samenow of The Washington Post wrote.Perhaps the most alarming detail in his piece: “In Northern Siberia, along the coast of the Arctic Ocean — where weather observations are scarce — model analyses showed temperatures soaring 40 degrees above normal on July 5, to over 90 degrees. ‘It is absolutely incredible and really one of the most intense heat events I’ve ever seen for so far north,’ wrote meteorologist Nick Humphrey, who offers more detail on this extraordinary high-latitude hot spell on his blog.”Scott Pruitt resigned as the head of the Environmental Protection Agency yesterday, after one of the most scandal-marred cabinet tenures of any official. Pruitt abused his office for personal gain in ways large, small and even ridiculous. Lydia O’Connor of HuffPost has a good list.Yet the worst thing about Pruitt’s tenure still wasn’t his personal corruption. It was his aggressive campaign to aggravate global warming, by rolling back federal attempts to combat it. Pruitt’s career — from Oklahoma attorney general to E.P.A. administrator — has been defined by his attempt to maximize the profits of energy companies, regardless of the effects on everyone else.That attitude will almost certainly outlast Pruitt, unfortunately. It is effectively the official policy of the Trump administration. You can expect many more heat waves in the years to come.“In the end, Mr. Pruitt was driven from office for having abused his position so outrageously,” the Times editorial board writes. “But if Mr. Trump continues down the same policy paths, as seems likely, Mr. Pruitt’s more lasting legacy, along with the president’s, will be an overheated planet and shortened life spans.” Frank Bruni also has a column on Pruitt.In a related story, the climate scientist Stefan Rahmstorf tweeted yesterday, “A new study based on evidence from past warm periods suggests global warming may be double what is forecast.” The study is available here.