2015 Smashes Global Temp Record
January 20, 2016
Above, for right brain dominant types, a musical recreation of global warming, courtesy reader Charlie Williams.
NOAA scientists confirmed today that 2015 set a new record for warmest average surface temperature on planet Earth. According to the press release:
During 2015, the average temperature across global land and ocean surfaces was 1.62°F (0.90°C) above the 20th century average. This was the highest among all years in the 1880-2015 record, surpassing the previous record set last year by 0.29°F (0.16°C). This is also the largest margin by which the annual global temperature record has been broken. Ten months had record high temperatures for their respective months during the year. The five highest monthly departures from average for any month on record all occurred during 2015. Since 1997, which at the time was the warmest year on record, 16 of the subsequent 18 years have been warmer than that year.
Scientists reported Wednesday that 2015 was the hottest year in recorded history by far, breaking a record set only the year before — a burst of heat that has continued into the new year and is roiling weather patterns all over the world.
In the contiguous United States, the year was the second-warmest on record, punctuated by a December that was both the hottest and the wettest since record-keeping began. One result has been a wave of unusual winter floods coursing down the Mississippi River watershed.
Scientists started predicting a global temperature record months ago, in part because an El Niño weather pattern, one of the largest in a century, is releasing an immense amount of heat from the Pacific Ocean into the atmosphere. But the bulk of the record-setting heat, they say, is a consequence of the long-term planetary warming caused by human emissions of greenhouse gases.
“The whole system is warming up, relentlessly,” said Gerald A. Meehl, a scientist at the National Center for Atmospheric Research in Boulder, Colo.
It will take a few more years to know for certain, but the back-to-back records of 2014 and 2015 may have put the world back onto a trajectory of rapid global warming, after a period of relatively slow warming dating to the last powerful El Niño, in 1998.
Politicians attempting to claim that greenhouse gases are not a problem seized on that slow period to argue that “global warming stopped in 1998” and similar statements, with these claims reappearing recently on the Republican presidential campaign trail.
Statistical analysis suggested all along that the claims were false, and the slowdown was, at most, a minor blip in an inexorable trend, perhaps caused by a temporary increase in the absorption of heat by the Pacific Ocean.
“Is there any evidence for a pause in the long-term global warming rate?” said Gavin A. Schmidt, head of NASA’s climate-science unit, the Goddard Institute for Space Studies, in Manhattan. “The answer is no. That was true before last year, but it’s much more obvious now.”
While global temperature records are normally measured in hundredths of degrees Fahrenheit, NOAA reports 2015 crushed the previous record just set in 2014 by nearly three tenths of a degree, or 0.29°F (0.16°C) above the previous record, which was set in 2014.
Last month was not just the hottest December on record, blowing out the previous record (set in 2014) by a staggering half degree — 0.52°F (0.29°C). NOAA reports “The December temperature departure from average was also the highest departure among all months in the historical record and the first time a monthly departure has reached +2°F from the 20th century average.”
The NOAA and NASA findings are consistent with other key global surface temperature datasets. For instance, Berkeley Earth — originally funded in part by deniers like Charles Koch to disprove global warming — reported last week that “2015 was unambiguously the hottest year on record.”
The blowout record warmth of 2015 erases the notion of a so-called pause in warming. NASA and Columbia University climatologists explain that “the updated global temperature record makes it clear that there was no global warming ‘hiatus’.” Similarly, Berkeley Earth’s Scientific Director Richard Muller, says 2015 “confirms our previous interpretation” that “global warming has not slowed.”
Far from slowing down, according to a number of studies last year from NOAA and others, we may well be entering an era of even more rapid global warming. Indeed, the combination of short-term warming from the ongoing El Niño with the long-term human-caused global warming trend mean that “2016 is likely to be at least as warm, if not warmer” than 2015, as UK Met Office research fellow Chris Folland explained in December. NOAA’s Tom Karl and NASA’s Gavin Schmidt told reporters Wednesday that the chances were better than even that 2016 will top 2015.
For the first time Earth is 1 degree Celsius (1.8 degrees Fahrenheit) warmer than it was in pre-industrial times, NOAA and NASA said. That’s a key milestone because world leaders have set a threshold of trying to avoid warming of 1.5 or degrees Celsius above pre-industrial times.
Because of the pace of rising temperatures, “we don’t have very far to go to reach 1.5,” Karl said.
But 1.5 or 2 degrees are not “magic numbers” and “we’re already seeing the impacts of global warming,” said NASA Goddard Institute of Space Studies director Gavin Schmidt.
“This trend will continue; it will continue because we understand why it’s happening,” Schmidt said. “It’s happening because the dominant force is carbon dioxide” from burning of fossil fuels like coal, oil and gas.
Although 2015 is now the hottest on record, it was the fourth time in 11 years that Earth broke annual marks for high temperature.
“It’s getting to the point where breaking record is the norm,” Texas Tech climate scientist Katharine Hayhoe said. “It’s almost unusual when we’re not breaking a record.”
December 2015 was the 10th month last year that set a monthly warmth record, with only January and April not hitting high marks.
“That’s the first time we’ve seen that,” said NOAA’s Karl.
You will not be surprised to know that 2015 was yet another hottest year ever recorded in the instrumental record, beating 2014 by a huge 0.13 °C. It was 1.25 °C hotter than pre-industrial. It is now 106 years since there was a “coldest year on record”.
Anyone who tries to tell you it hasn’t warmed since 1996, or 1997, or 1998, is dead wrong.
In the midst of this, a senior scientist emails me “..By the way january is currently 0.05 hotter than December.”