Mario Tama / Getty

The 2010s were the hottest decade ever measured on Earth, and 2019 was the second-hottest year ever measured, scientists at NASA and the National Oceanic and Atmospheric Administration announced today.

After a year of flash droughts, rampant wildfires, and searing heat waves that set all-time records across Europe and turned parts of Greenland’s ice sheet into slush, the finding was not a surprise to researchers, or likely anyone else. But it capped an anxious decade that saw human-caused climate change transform from a far-off threat into an everyday fact of life.

Last year was 1.8 degrees Fahrenheit—or just under 1 degree Celsius—warmer than the 20th-century average, Gavin Schmidt, the chief climate scientist at NASA, said at a briefing announcing the news. Almost everywhere on the planet’s surface was warmer than average, though the Arctic was especially searing. “Every decade since the 1960s has been warmer than the decade previous,” he said.

In short, it’s bad, but you probably knew that already. At least four different groups of scientists, each working independently, have now concluded that the 2010s were the hottest decade of the modern era. (NASA and NOAA start this era at 1880, when they say weather record-keeping became reliable and widespread enough to trust, but the nonprofit research agency Berkeley Earth argues that 2019 was the second-warmest year since at least 1850.) What’s worse is that greenhouse-gas pollution from fossil fuels, which are the biggest driver of climate change, also surged to an all-time high last year, according to a preliminary estimate. Deke Arndt, a chief climate scientist at NOAA, said at the briefing that “an obvious signal” of this greenhouse-gas-powered heating had appeared in the upper layers of the ocean, which broke the all-time heat record last year.

Let’s be honest: “Last year was one of the hottest years ever recorded” has become a common story. It’s news in the same way the most popular boys’ baby names are news. (Wow, dear, did you see James won again?) The climate scientist Joseph Majkut quipped that the tone of this year’s announcement was less “See, see we told you” and more “Well, duh.”

Schmidt, the NASA scientist, nodded at this during the briefing. “The fact is, the planet is warming, and every year we add one extra data point to this graph, which may not seem like a terribly important thing, but people seem interested,” he said. “The main thing here is not the ranking … but the consistency of the long-term trend we’re seeing.” Virtually every important climate record has been broken and re-broken over the past few years: The past five years are the five warmest years on record, the past six the warmest six, the past nine the warmest nine. Since Donald Trump rode down his gilded escalator and announced he was running for president, the world has experienced its hottest recorded version of each individual month, according to NOAA.

So it’s worth going back in history to see just how outlandish our current situation is. The median American is a little more than 38 years old. The year before she was born was 1980. It was, at the time, the hottest year ever measured. A July heat wave that year killed 1,265 Americans and caused more than $20 billion in damage nationwide.

The larger significance of this milestone was not well understood at the time. In an op-ed that summer, a weatherman in Westchester, New York, expressed so much regret about giving in and buying a car with an air conditioner that he wondered whether Americans of his demographic were “less tolerant of extreme heat than our parents and grandparents.” His parents’ generation made do without air-conditioned cars, he figured, and his grandparents didn’t even have electric ceiling fans. Were they a tougher breed?

They were not, he learned: The weather had gotten warmer. He was shocked. “It came as a great surprise to discover that during the first three decades of this century there were fewer heat waves (27) than during the last three (49),” he wrote in The New York Times. “My hat is off to the present generation … If we create our own cooler environment with air conditioners, well then, we deserve it.”

His editorial did not mention global warming or “the greenhouse effect,” as it was then called. And the hottest-year record probably did seem like a fluke: 1980 was the first time the record had been broken in 35 years.

In 1981, the median American was born, a happy and healthy statistical girl. The planet inched even hotter, setting a new all-time record a few hundredths of a degree Celsius warmer than 1980’s. Then, in 1983, as she learned to string sentences together, the record was smashed again. The global hottest-year record had now been broken three times in four years.

A few years passed, all of them warmer than average but not record-breakingly so. She started school. As our median American entered first grade, in 1987, the world again experienced its hottest year ever. Now the planet’s new all-time heat record was a tenth of a degree Celsius warmer than it had been in 1980.

Then 1988 began. Its first five months were hotter than any comparable period—hotter than all those record-breaking years that had just happened. “It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here,” James Hansen, a lead NASA climate scientist, told Congress in June. His declaration was front-page news. George H. W. Bush, campaigning for president, promised to do something about it: “Those who think we are powerless to do anything about the greenhouse effect forget about the ‘White House’ effect,” he declared on the trail. By the end of the year, our median American was in second grade, Bush was president, and Hansen’s prediction had borne out: 1988 was even hotter than 1987. It was the new hottest year on record.

She kept growing up; 1989, third grade, was among the five warmest years ever measured. The Berlin Wall fell. The years 1990 and 1991 were even hotter: the two new warmest years ever measured, each toastier than 1988, 1987, or any other year in the observed NOAA record. In June 1991, as the American wrapped up fifth grade, a massive volcano named Mount Pinatubo erupted in the Philippines. Its ash blocked sunlight and cooled global temperatures in 1992, the same year Bill Clinton was elected. Clinton’s vice president, Albert Gore, had warned a few years earlier of an “ecological Kristallnacht” aggravated by heat-trapping greenhouse-gas pollution in the atmosphere. Yet Clinton and Gore failed to pass an early version of a climate policy, a “BTU tax” on energy use, in 1993, the following year. It was a funny time: 1993, even though it was cooled by Mount Pinatubo’s ash, was still as hot as 1980—which had once been the hottest year ever measured. Then 1994 arrived. It was even hotter than ’93.

The median American started high school in 1995, and temperatures began to surge to new highs. That year was the new hottest year ever. A five-day heat wave killed more than 700 people in Chicago alone, one of the deadliest American natural disasters of all time. The next year, 1996, though not as bad, was still among the 10 hottest years ever. 1997 pushed through 1995’s record and became the new all-time-hottest year measured. Then a monstrous El Niño lifted 1998 even higher—the hottest year of the 20th century, it was more than twice as far from the century’s average as 1980. And as the median American graduated from high school in 1999, about 16 percent of the world’s coral reefs were dying or dead.

The new century arrived. The years of her early twenties—2001, 2002, and 2003—were each hotter than any year in the 20th century except 1998. In 2003, then the second-hottest year ever, a continent-sized heat wave killed as many as 70,000 people in Europe. Two years later, 2005 set a new hottest-year-ever record. The years 2006, 2007, and 2009 were all among the five warmest on record. Then 2010 broke the all-time heat record again. That same year, the Obama administration failed to pass a massive climate bill through the Senate.

She turned 30 in 2011, which was both a chill year for this century—and warmer than any year before 1997. The years 2012 and 2013 were among the five hottest ever. Then came the three-peat: 2014 broke 2010’s all-time record, then 2015 was even hotter, then 2016 was hotter still. On land, 2016 was nearly 4 degrees Fahrenheit warmer than the 20th-century baseline.

It was three times as hot over the baseline as 1981, the year she was born.

We want to hear what you think about this article. Submit a letter to the editor or write to