November 2015 is second-warmest in known history, NASA says, as this year stays on track for record warmth
November 2016 was the second-warmest November in recorded history, NASA’s Goddard Institute for Space Studies announced last week, with an average global temperature that was less than one-tenth of a degree Celsius lower than the record-setter of 2015.
Last month was also 0.95 degrees Celsius (1.71 degrees Fahrenheit) warmer than the average November during the years between 1951-1980 and kept Earth on the path to the warmest year the planet has experienced in the 136 years in which consistent weather records have been maintained.
November 2015 was 1.02 degrees Celsius warmer than the mean for the month during that 29-year period.
The National Oceanic & Atmospheric Administration announced Monday that, according to its calculations, November 2016 was the fifth-warmest in recorded history. NOAA said that last month’s average global temperature was 0.72 degrees Celsius (1.31 degrees Fahrenheit) above the norm for the month.
NOAA’s assessment of the month’s place in climate history is based on 122 years of records.
As the year approaches its end, there is little doubt that it will be the warmest known in either 122 or 136 years. NOAA’s statement explained that this year’s average temperature to date is 0.94 degrees Celsius (1.69 degrees Fahrenheit) above the mean for the past 122 years, while NASA’s methods indicate that the year-to-date mean temperature is 1.02 degrees Celsius (1.84 degrees Fahrenheit) above that for the period 1951-1980.
Earth’s Arctic region has been the part of the planet where warmth has been most pronounced this year.
NOAA’s 2016 Artic Report Card, which the agency released earlier this month, indicated that the extent of summer sea ice in the region this year was tied with 2007 for the second-lowest since 1979 and that average surface air temperatures there in the year that ended on Sept. 30 were the highest since at least 1900.
The mean air temperature in the Arctic has warmed by 3.5 degrees Celsius (6.3 degrees Fahrenheit) since 1900, a pace that is twice as fast as that experienced by the rest of Earth.
The continental United States experienced warmer temperatures than normal for the first 11 months of this year from coast-to-coast and from northern border to southern border. This graphic, prepared by the National Centers for Environmental Information, shows that no region in the mainland U.S. experienced an average temperature that is lower than the mean of the past 122 years:
August 2016 was the warmest month in recorded history, tying July 2016 for that distinction.
NASA said Monday that the mean worldwide temperature during August was 0.16 degrees Celsius hotter than the previous record-setting August and 0.98 degrees Celsius hotter than the average August between 1951-1980.
According to analysis completed by the agency’s Goddard Institute for Space Studies, August 2016 was the eleventh month in a row to reach a new high for that month’s average worldwide temperature.
The records kept falling as July 2016 set new benchmarks for heat.
NASA said Aug. 16 that last month was not only the hottest July in recorded history, but also the hottest month known since temperature record-keeping began in 1880.
“It wasn’t by the widest of margins, but July 2016 was the warmest month since modern record keeping began in 1880,” Dr. Gavin Schmidt, director of the agency’s Goddard Institute for Space Studies, said. “It appears almost a certainty that 2016 also will be the warmest year on record.”
This July’s mean temperature was 0.1 degrees warmer than the previous July record holders that occurred in 2015, 2011, and 2009, according to NASA’s study.
The National Oceanic & Atmospheric Administration confirmed July’s status as the heat pacesetter for all months on Aug. 17.
NOAA said that July 2016 was 1.57 degrees Fahrenheit warmer than the average 20th century July and 0.11 degrees Fahrenheit above the previous record-holding month of July 2015.
That continued a decades-long trend for the month of the year that is the peak of summer in the northern hemisphere.
“July 2016 marks the 40th consecutive July with temperatures at least nominally above the 20th century average,” NOAA’s National Centers for Environmental Information said in a summary of the July temperature data. “July 1976 was the last time July global land and ocean temperatures were below average.”
The trend is not limited to every year’s July.
A new record for the warmest month of its kind has been set in each of the past ten months, according to NASA, dating back to October 2015.
NOAA pegged the hot streak at 15 record-setting months in a row.
The disparity is the result of differing methodologies used by the two agencies.
For the year of 2016 through the end of July, NOAA found that mean worldwide temperatures were 1.85 degrees Fahrenheit above the 20th century average.
The next-hottest January-July period came in 2014, when the average was 0.34 degrees F below this year’s measurement.
Both agencies use meteorological stations around the world to obtain air temperature data and ship- and buoy-based instruments to measure sea surface temperature. Antarctic research stations are also used to gather the data that underlies their monthly global temperature analysis reports.
A United Nations agency has predicted that the planet’s recent streak of record-setting hot years will reach a new threshold this year.
The World Meteorological Organization also noted in the July 21 statement that the concentration of atmospheric carbon dioxide has reached “new highs.”
The current level of CO2 in the atmosphere exceeds 400 parts per million, a concentration not known on Earth since the Pliocene epoch, which ended about 1.8 million years ago.
In June the average concentration reached 407 parts per million, which was 4 ppm greater than in June 2015.
A WMO official pointed to the trend as a reason to emphasize public policies aimed at reducing greenhouse gas emissions.
“This underlines more starkly than ever the need to approve and implement the Paris Agreement on climate change, and to speed up the shift to low carbon economies and renewable energy,” Petteri Taalas, the agency’s secretary-general, said.
The WMO statement highlighted a streak of record-setting hot months in its prediction.
NOAA also said that June was the 14th consecutive month to set a heat record.
“Another month, another record,” Taalas said. “And another. And another. Decades-long trends of climate change are reaching new climaxes, fueled by the strong 2015/2016 El Niño.”
WMO also pointed to reduced Arctic sea ice during summer months, increased precipitation in some regions, and widespread bleaching of coral reefs as indicators of the climate trend that is likely to put 2016 in the record books.
May continued a streak of record setting hot months as average temperatures were nearly a whole degree Celsius above the previously hottest May.
NASA’s Goddard Institute for Space Studies said Tuesday that the mean global temperature during the year’s fifth month was 0.93 degrees Celsius, or 1.67 degrees Fahrenheit, than the average for May.
That made May 2016 the eighth consecutive month, according to NASA records, to break the record for warmth.
The previous record-holding May occurred in 2014.
Japan’s meteorological agency reached a slightly different conclusion, concluding that May 2016 was the second-warmest May on record.
Another U.S. federal agency, the National Oceanic & Atmospheric Administration, has yet to release its measurement of average May temperatures. NOAA uses the same data as NASA but analyzes measured temperatures differently.
NASA’s method depends on a dataset called the GISS Surface Temperature Analysis. GISTEMP includes records from 6,300 meteorological stations scattered around the planet, ship-based and satellite observations of sea surface temperatures, and research stations in Antarctica. The GISTEMP data goes back to 1880.
Although May was another record-setting month, in terms of heat, it was not as anomalous as the seven prior months. Between October 2015 and April 2016 the monthly average temperature exceeded the previous record-holding month by at least one degree Celsius.
The explanation for the lessened disparity in heat between May 2016 and previous Mays in the temperature record might be related to the approaching end of a powerful El Nino event.
Nevertheless, at least according to one climate scientist, May’s record-setting mean temperature means that the rolling 12-month average has now exceeded one degree Celsius above the norm for the period 1951-1980.
Humanity’s ongoing alteration of Earth’s atmosphere has now caused eleven straight months of record heat.
The National Oceanic & Atmospheric Administration announced April 19 that March continued the streak with an average worldwide temperature that was 2.2 degrees Fahrenheit above the twentieth century average for the month.
The month cemented the place of 2016’s first quarter as the warmest three-month period, relative to the norm, in recorded history.
“The departures are what we would consider astronomical,” NOAA climate scientist Jessica Blunden told the Associated Press. “It’s on land. It’s in the oceans. It’s in the upper atmosphere. It’s in the lower atmosphere. The Arctic had record low sea ice.”
“Everything everywhere is a record this month, except Antarctica,” Blunden continued in her AP interview. “It’s insane.”
March 2016 exceeded the previous record departure from the March mean for the period 1880-2016 by 0.54 degrees Fahrenheit.
The heat was particularly evident over land, where air temperatures last month were 4.19 degrees Fahrenheit above the twentieth century mean.
The agency also said that the average temperature above both land and sea surfaces across the globe during the first three months of this year was 2.07 degrees Fahrenheit higher than the twentieth century average. That is another record, exceeding the previous record set last year by 0.5 degrees Fahrenheit.
In the United States record heat was experienced in nearly every part of the country.
Deke Arndt, the leader of the climate monitoring branch at NOAA’s National Centers for Environmental Information, wrote in an April 12 blog post that every one of the nation’s climate divisions – sections distinguished by long-term climate patterns – was “warmer than normal” last month.
“The nationwide warmth was the result of unusual, and in some cases, record warmth, generally moving west to east across the CONUS,” Arndt wrote.
The acronym CONUS refers to the continental United States.
Up in the Arctic, the seasonal ice cover continued to shrink in March.
The average amount of territory in the Arctic that was covered by ice during the month was 7.02 percent below the 1981-2010 average and was the second-smallest ice cover during March since record-keeping began in 1979.
Arctic sea ice reached its maximum extent on March 24. Covering 14.52 million square kilometers (5.61 million square miles), it was the smallest maximum on record and was 1.12 million square kilometers (431,000 square miles) below average.
“I’ve never seen such a warm, crazy winter in the Arctic,” Dr. Mark Serreze, director of the National Snow and Ice Data Center in Boulder, Colo. and a professor of geography at the University of Colorado, said. “The heat was relentless.”
Serreze explained that, while the powerful El Nino that occurred this past winter may have helped drive down Arctic ice cover by causing circulation of warm air currents, the overall trend downward cannot be attributed to ENSO events.
“The system has always been variable,” he said. “It’s not like we’re going to set a new record each year. That’s not how the system works. If we recovered in the next year or two that would not be a surprise at all, but it would only be a temporary recovery.”
The average air temperature in the Arctic between Dec. 1 – Feb. 28 was 4-11 degrees Fahrenheit above average for that time period, according to an NSIDC press release.