The decade that just ended was by far the hottest ever measured on Earth, capped off by the second-warmest year on record, two U.S. agencies reported Wednesday. And scientists said they see no end to the way man-made climate change keeps shattering records.
"This is real. This is happening," Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, said at the close of a decade plagued by raging wildfires, melting ice and extreme weather that researchers have repeatedly tied to human activity.
The 2010s averaged 58.4 degrees Fahrenheit (14.7 degrees Celsius) worldwide, or 1.4 degrees (0.8 C) higher than the 20th century average and more than one-third of a degree (one-fifth of a degree C) warmer than the previous decade, which had been the hottest on record, according to the National Oceanic and Atmospheric Administration.
The decade had eight of the 10 hottest years on record. The only other years in the top 10 were 2005 and 1998.
NASA and NOAA also calculated that 2019 was the second-hottest year in the 140 years of record-keeping. Five other global teams of monitoring scientists agreed, based on temperature readings taken on Earth's surface, while various satellite-based measurements said it was anywhere from the hottest year on record to the third-hottest.
Several scientists said the coming years will be even hotter, knocking these years out of the record books.
"If you think you've heard this story before, you haven't seen anything yet. This is going to be part of what we see every year until we stabilize greenhouse gases" from the burning of coal, oil and gas, said Schmidt, who was at the American Meteorological Society convention in Boston, where last weekend it was so warm he went jogging in shorts and a T-shirt. Boston had its hottest January day on Sunday, at 74 degrees, which is 2 degrees warmer than the old record.
"It's sobering to think that we might be breaking global temperature records in quick succession," said Georgia Tech climate scientist Kim Cobb. "2020 is off to a horrifying climate start, and I fear what the rest of the year will bring to our doorsteps."
Since 1980 high-cost disasters such as hurricanes and flooding have totaled more than $1.75 trillion in damage. They're becoming more frequent, and more damaging.
NASA's Schmidt said that overall, Earth is now about 1.2 degrees C (nearly 2.2 F) hotter since the beginning of the industrial age, a number that is important because in 2015 global leaders adopted a goal of preventing 1.5 C (2.7 F) of warming since the rise of big industry in the mid- to late 1800s. He said that shows the global goal can't be achieved. (NOAA and the World Meteorological Organization put the warming since the dawn of industry slightly lower.)
"We have strong human-induced global warming," said Friederike Otto, a climate scientist at the University of Oxford. "What we observe here is exactly what our physical understanding tells us to expect and there is no other explanation."
Other explanations that rely on natural causes — extra heat from the sun, more reflection of sunlight because of volcanic particles in atmosphere, and just random climate variations — "are all much too small to explain the long-term trend," Princeton University climate scientist Michael Oppenheimer said.
Scientists said the the decade-long data is more telling than the year-to-year measurements, where natural variations like El Nino, the periodic warming of the Pacific Ocean, come into play.
"Human-caused climate change is responsible for the long-term warming — it's responsible for why the 2010s were warmer than 2000s, which were warmer than the 1990s, etc.," Texas A&M University climate scientist Andrew Dessler said in an email. "But humans are not responsible for why 2016 was warmer than 2015 or why 2019 was warmer than 2018."
NOAA said the average global temperature in 2019 was 58.7 degrees (14.85 C), or just a few hundredths of a degree behind 2016, when the world got extra heat from El Nino. That's 1.71 degrees (0.95 C) higher than the 20th century average and 2.08 degrees (1.16 C) warmer than the late 19th century.
The past five years have been the hottest five on record, nearly 1.7 degrees (0.9 C) warmer than the 20th century average, according to NOAA.
The last year Earth was cooler than the 20th century average was 1976, before Democratic presidential candidate Pete Buttigieg, French President Emmanuel Macron and Donald Trump Jr. were born.
If you want to know what this means for people and the world, just look at wildfire-stricken Australia, Schmidt and others said.
Global warming is already being seen in heat waves, ice sheet melt, more wildfires, stronger storms, flood-inducing downpours and accelerating sea level rise, said Hans-Otto Portner, who heads the U.N. Intergovernmental Panel on Climate Change team that looks at the impact of climate change.
Dr. Renee Salas, a Boston emergency room physician and Harvard professor who studies climate change's effects on health, said "these temperatures are not just statistics but have names and stories," mentioning a construction worker and an elderly man with no air conditioning who were her patients this summer.
"The planet has a fever," Salas said, "and that's its symptom."
From arctic blasts to heat waves, this year's weather broke more than 120,000 records in the US
This year's extreme weather broke more than 120,000 daily records across the US -- from temperatures to precipitation and snowfall records, according to the National Climatic Data Center.
While the total number of daily records aren't that unusual compared to previous years, meteorologist Guy Walton told CNN, the bigger picture is.
"We should see the wettest year in recorded history, or at least since records have been kept in 1895," Walton said, who has spent more than 30 years as a meteorologist.
The Midwest was particularly hit hard earlier this year, with large areas under water. The flooding devastated farms in parts of Nebraska and Iowa, killing livestock and ruining harvests.
And climate experts suggest the extreme nature of this year's weather -- from record flooding to record highs -- is a red flag.
It was 70 degrees in Alaska. In March
There were a lot of first-time-evers for communities across the US.
The first time Nick Dombek's five-year-old son saw snow falling at their house on the east side of Tallahassee, Florida.
The first time Assistant Chief Bimbo Gifford had to battle a fire in freezing temperatures with wind chills of minus-50 degrees. He's been a volunteer with Wisconsin's Cameron Fire Department for decades.
The first time Alaska saw 70-degree weather as early as March. And with the Arctic warming twice as fast as the rest of the plane, the summer was no better.
On the Fourth of July, Anchorage was hotter than Key West at 90 degrees, setting a new all-time record, according to the National Weather Service.
All this has meant a lack of sea ice for Alaska this fall, according to the National Park Service, with ice coverage in the Arctic at the lowest levels ever recorded. Which is critical to the coast's ecosystem, since sea ice sustains millions of organisms.
"You'll see that when it comes to alarming changes, the last frontier feels like the first in line," CNN Chief Climate Correspondent Bill Weir said after traveling across Alaska this summer.
And across the Southeast, it was a seemingly "never-ending summer," with temperatures up to 100 degrees lasting into October, CNN Meteorologist Brandon Miller said.
The unseasonable heat has been part of the larger pattern of climate change. And Walton says a new state will have to brace for the global domino effect -- Hawaii.
Hawaii state park sees snow for the first time
Despite its tropical climate, Hawaii has seen hundreds of record highs this year. And record lows. Like near Maui's Polipoli State Park, when it was blanketed by snow.
"For perhaps the first time ever, snow has fallen in a Hawai'i State Park," the Department of Land and Natural Resources said in February. "It could be the lowest elevant snow ever recorded in the state."
But Walton points to the hundreds of record highs the islands experience this year.
Like the 97-degrees recorded in late September by a weather station near the Honolulu Zoo, setting an all-time record, according to the NCDC.
"Beyond temperatures getting more uncomfortable in an already warm environment, our 50th state will get more susceptible to organized tropical activity moving from the east and south due to an overall hotter surroundings," Walton said on his site tracking historical weather data.
"To sum up," Walton said, "here we have one more case for a warming world."
Read more stories on climate issues by The Associated Press.
Follow Seth Borenstein on Twitter.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.