Last year was the hottest on earth since record-keeping began in 1880, scientists reported on Wednesday, continuing a steady long-term warming trend spurred by the burning of fossil fuels.
While El Nino contributed to the surge — heating ocean temperatures in the months of October, November and December — almost every month in 2015 broke all-time previous high global average temperatures, according to independent analyses by NASA and the National Oceanic and Atmospheric Administration.
Globally-averaged temperatures in 2015 broke the previous mark set in 2014 by 0.23 degrees Fahrenheit. Only once before, in 1998, has the new record been greater than the old record by this much.
“It is a steady warming, with no evidence of change in the long term,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies in New York.
The warming of the earth means that sea ice and mountain glaciers will continue to melt, raising sea levels, said Schmidt and Thomas R. Karl, director of NOAA’s National Centers for Environmental Information in Asheville, North Carolina, and chair of the Subcommittee on Global Change Research for the U.S. Global Change Research Program in Washington.
They also predicted more extreme weather events, such as increased heat waves, more frequent hurricanes and greater rain storms.
“It is happening because the dominant force — the increase in carbon dioxide, caused by deforestation and burning of fossil fuels — is increasing,” said Schmidt.
“It is up to policymakers and society to decide what to do with that information,’ he said.
The scientists predicted that 2016 is likely to also break records, which would create the first-ever three year trend — undermining claims by climate change contrarians that global warming concerns are hyped.
“What we will see is more and clearer impacts as we warm,” said Schmidt. “We are on a trajectory because the carbon cycle is out of balance now. It can’t be turned around instantly.”
While commending December’s landmark accord in Paris that commits 195 nations to lowering greenhouse gas emissions, “it can’t be turned around instantly,” said Schmidt.
“A sustained effort is required to shift emissions,” he said. “There has to be a sustained conversation for this problem to get under control.”
