WASHINGTON (Reuters) - Last year's global average temperature was the hottest ever by the widest margin on record, two U.S. government agencies said on Wednesday, adding to pressure for deep greenhouse gas emissions cuts scientists say are needed to arrest warming that is disrupting the global climate.
Data from the U.S. space agency NASA and the National Oceanic and Atmospheric Administration showed that in 2015 the average temperature across global land and ocean surfaces was 1.62 degrees Fahrenheit (0.90 Celsius) above the 20th century average, surpassing 2014's previous record by 0.29 F (0.16 C).
Scientists at the United Kingdom's Met Office and East Anglia's Climatic Research Unit also published data on Wednesday confirming the U.S. agencies findings.
This was the fourth time a global temperature record has been set this century, the agencies said in a summary of their annual report.
"2015 was remarkable even in the context of the larger, long-term warming trend," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies.
The sharp increase in 2015 was driven in part by El Niño, a natural weather cycle in the Pacific that warms the ocean surface every two to seven years. But scientists say human activities -- notably burning fossil fuels - were the main driver behind the rise.
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US agencies say 2015 was hottest on record, shatters records
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Cal Fire engineer Clint Singleton looks out at a plume of smoke near Clearlake, Calif., Wednesday, Aug. 5, 2015. Thousands of firefighters battling an unruly Northern California wildfire were aided overnight by cooler temperatures and higher humidity, but the fire is still less than a quarter contained. (AP Photo/Jeff Chiu)
Corn damaged by heavy rains stands in a field in Sheridan, Ind., Wednesday, Aug. 12, 2015. The U.S. Department of Agriculture says farmers in 88 of Indiana's 92 counties are eligible for low-interest emergency loans because of heavy rains and flooding that have occurred since May 1. (AP Photo/Michael Conroy)
In a view from Whittier, Calif., the sun sets behind a hazy downtown Los Angeles after a week of high temperatures from the view Tuesday, Aug. 18, 2015. (AP Photo/Nick Ut)
A child plays in the sprinklers of Seward park, Monday, Aug. 17, 2015, in New York. Temperatures are expected to reach into the 90s in the New York metro area. (AP Photo/Mary Altaffer) (AP Photo/Mary Altaffer)
Beach goers crowd at Venice Beach, Calif., Sunday, Aug. 16, 2015. The Western heat wave began Thursday and was expected to continue through Sunday. Authorities warned people not to leave small children or pets in cars, where temperatures can quickly soar. Los Angeles and other cities were keeping libraries and other facilities open late to serve as cooling shelters for those without air conditioning.(AP Photo/Ringo H.W. Chiu)
Storm clouds build over the left field stands in Coors Field during the fifth inning of an inter league baseball game between the Seattle Mariners and the Colorado Rockies Monday, Aug. 3, 2015, in Denver. (AP Photo/David Zalubowski)
Debris rests on the ground after a garage was damaged by fallen tree during a severe thunderstorm in Traverse City, Mich., Sunday, Aug. 2, 2015. Authorities said gusts as high as 65 mph left thousands without power, damaged houses and left some roads impassable. (AP Photo/John Flesher)
A vehicle drives through a puddle after heavy rainfall, Tuesday, Aug. 11, 2015, in Albany, N.Y. Scattered rain and thunderstorms are expected in the region through Wednesday. (AP Photo/Mike Groll)
Firefighters walk under smoke from fires along Morgan Valley Road near Lower Lake, Calif., Friday, July 31, 2015. A series of wildfires were intensified by dry vegetation, triple-digit temperatures and gusting winds. (AP Photo/Jeff Chiu)
LAKE MEAD NATIONAL RECREATION AREA, NV - AUGUST 03: The ruins of the Hannig Ice Cream Parlor are shown in the ghost town of St. Thomas on August 3, 2015 in the Lake Mead National Recreation Area, Nevada. The town was founded in 1865 by Mormon pioneers at the site where the Muddy River flowed into the Colorado River and at one point had about 500 settlers. The town was abandoned in 1938 after the construction of the Hoover Dam caused the Colorado River to rise. The area was once submerged in 60 feet of water but became entirely exposed to the air as a severe drought in the Western United States over the last 15 years has caused Lake Mead to drop to historic low levels. (Photo by Ethan Miller/Getty Images)
UNITED STATES - JULY 30: A severe thunderstorm passes over the U.S. Capitol on Thursday, July 30, 2015. (Photo By Bill Clark/CQ Roll Call)
Clouds accompany hot, muggy weather over downtown Los Angeles and the Walt Disney Concert Hall, Thursday, July 30, 2015. July is wrapping up in California with more of the unusual weather that has marked the normally very dry month. Flash-flood watches are posted across the interior mountains and deserts of southern and eastern California as monsoonal moisture brings thunderstorms.(AP Photo/Nick Ut)
Motorists drive through heavy rain along Ninth Avenue, Thursday, July 30, 2015 in New York. More showers are predicted through the night, but skies are expected to clear by Friday morning. (AP Photo/Julie Jacobson)
Two youths play in the Swann Memorial Fountain Thursday, July 30, 2015, in Philadelphia. According to the National Weather Service temperatures are expected to reach 90-degrees. (AP Photo/Matt Rourke)
Young people cross a street during a rainstorm Thursday, July 30, 2015, in Philadelphia. According to the National Weather Service temperatures are expected to reach 90-degrees. (AP Photo/Matt Rourke)
Walter Swinehart cools off in the Swann Memorial Fountain, Thursday, July 30, 2015, in Philadelphia. According to the National Weather Service temperatures are expected to reach 90-degrees. (AP Photo/Matt Rourke)
A man cools off in the water sprinklers at Sara Delano Roosevelt Park, Wednesday, July 29, 2015, in New York. The National Weather Service has issued a heat advisory for New York City through 8 p.m. Thursday. (AP Photo/Mary Altaffer)
Clouds hang over City Hall Tuesday evening, July 28, 2015, in Commerce City, Colo. Forecasters predict continued warm weather for Colorado's Front Range communities in the week ahead. (AP Photo/David Zalubowski)
Storm clouds build over the Rocky Mountains in Colorado as the sun sets late Friday, July 24, 2015. Forecasters predict that the cool, stormy weather of Friday will move out for daytime highs hovering in the 90s for the weekend ahead. (AP Photo/David Zalubowski)
In this Tuesday, July 21, 2015, photo, Wendover Mayor Mike Crawford stands along the exposed mud track on the Bonneville Salt Flats, in Utah. Crawford, who owns an auto parts shop in town, said the decision by race organizers to cancel this yearâs event weeks away will be a bigger economic blow than last year, when a monsoon storm left standing water on the track on the eve of the race. Wet weather has forced the second-straight cancellation of an annual race at Utahâs world-famous Bonneville Salt Flats. (AP Photo/Rick Bowmer)
A teenager checks his cell phone as storm clouds pass Friday, July 17, 2015, in Zionsville, Ind. Scattered storms were in the forecast for most of Friday evening. (AP Photo/Darron Cummings)
Storm clouds hang over Great American Ball Park before the MLB All-Star baseball game, Tuesday, July 14, 2015, in Cincinnati. (AP Photo/Jeff Roberson)
Smoke drifting south from wildfires burning in Canada clouds the skyline Tuesday, July 7, 2015, in Denver. A smoke advisory was issued for the northeastern part of Colorado, Monday and expanded to all counties east of the Continental Divide Tuesday. (AP Photo/David Zalubowski)
Vehicles struggle to navigate through the intersection of Eighth Avenue and Grant Street south of downtown Denver as a severe thunderstorm swept over the metropolitan area late Thursday, June 25, 2015. Forecasters have issued a severe thunderstorm warning for communities south and east of Denver for Thursday night. (AP Photo/David Zalubowski)
NEW YORK, NY - AUGUST 17: People enjoy a hot afternoon at the Astoria Pool in the borough of Queens on August 17, 2015 in New York City. The main pool, the biggest in New York City and administered by the New York City Department of Parks and Recreation, sees over 3,000 people on a typical summer weekday. New York city is in the middle of a heat wave, with temperatures in the high nineties and with a heat factor making it feel over 100 degrees. (Photo by Spencer Platt/Getty Images)
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"The 2015 data continues the pattern we've seen over the last four to five decades," said Thomas Karl, director of NOAA's National Centers for Environmental Information.
The latest El Niño started in late 2015 and will last until spring 2016. It is among the strongest ever recorded but Schmidt and others say the weather phenomenon played just a supporting role in the earth's temperature rise.
The 2015 data underscores the urgency of cutting greenhouse gas emissions if the world is to hold temperature increases to well below 2 degrees C, the target agreed to by more than 190 countries at climate talks in Paris last December, scientists said.
With the global mean surface temperature in 2015 more than 1 degree C above late-19th century levels, the world is now halfway to the U.N. target, which would require stronger greenhouse gas emissions cuts.
"This announcement should put pressure on governments to urgently implement their commitments to act against climate change, and to increase the strength of their planned cuts in annual emissions of greenhouse gases," said Bob Ward, policy director of the Grantham Research Institute on Climate Change and the Environment in London.
In the United States, some Republican lawmaker and those skeptical of human-caused climate change have pointed to a slowdown in temperature rise after the last powerful El Niño in 1998 as a sign that climate change is not a serious problem.
Republican presidential candidate Ted Cruz said in December at a hearing on climate change science that there had been no significant global warming for the past 18 years.
NOAA's Karl said that with two back-to-back years of record warming, likely to be followed with a third next year, any doubts that have been raised by skeptical lawmakers about a pause in global warming can be put to rest.
"There is no sign of a pause and slowing," Karl told reporters Wednesday, adding that it is a safe bet that 2016 will break the 2015 record given the long-term trend and the impact of El Niño in the first quarter of the year.
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