NASA: First 6 Months Of Year Warmest To Date

Scientists at NASA say two key climate change indicators — global surface temperatures and Arctic sea ice extent — have broken numerous records through the first half of 2016.

Each of the first six months of 2016 set a record as the warmest respective month globally in the modern temperature record, which dates to 1880, according to scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York. The six-month period from January to June was also the planet’s warmest half-year on record, with an average temperature 1.3°C (2.4°F) warmer than the late nineteenth century.

This color-coded map in displays global surface temperature anomalies for the period January 2016 through June 2016. Higher than normal temperatures are shown in red and lower then normal termperatures are shown in blue. (Credit: NASA/GISS)

This color-coded map in displays global surface temperature anomalies for the period January 2016 through June 2016. Higher than normal temperatures are shown in red and lower then normal temperatures are shown in blue. (Credit: NASA/GISS)

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Five of the first six months of 2016 also set records for the smallest respective monthly Arctic sea ice extent since consistent satellite records began in 1979, according to analyses developed by scientists at NASA’s Goddard Space Flight Center, in Greenbelt, MD. The one exception, March, recorded the second smallest extent for that month.

While these two key climate indicators have broken records in 2016, NASA scientists said it is more significant that global temperature and Arctic sea ice are continuing their decades-long trends of change. Both trends are ultimately driven by rising concentrations of heat-trapping carbon dioxide and other greenhouse gases in the atmosphere.

The extent of Arctic sea ice at the peak of the summer melt season now typically covers 40% less area than it did in the late 1970s and early 1980s. Arctic sea ice extent in September, the seasonal low point in the annual cycle, has been declining at a rate of 13.4% per decade.

A graph of the global mean surface temperature for the six-month period of January through June of each year from 1880-2016. The numbers are the differences from the pre-industrial era, calculated as the average mean surface temperature of 1880-1899. (Credit: NASA/GISS)

A graph of the global mean surface temperature for the six-month period of January through June of each year from 1880-2016. The numbers are the differences from the pre-industrial era, calculated as the average mean surface temperature of 1880-1899. (Credit: NASA/GISS)

“While the El Niño event in the tropical Pacific this winter gave a boost to global temperatures from October onwards, it is the underlying trend which is producing these record numbers,” GISS Director Gavin Schmidt said.

Previous El Niño events have driven temperatures to what were then record levels, such as in 1998. But in 2016, even as the effects of the recent El Niño taper off, global temperatures have risen well beyond those of 18 years ago because of the overall warming that has taken place in that time.

The global trend in rising temperatures is outpaced by the regional warming in the Arctic, said Walt Meier, a sea ice scientist at NASA Goddard.

“It has been a record year so far for global temperatures, but the record high temperatures in the Arctic over the past six months have been even more extreme,” Meier said. “This warmth as well as unusual weather patterns have led to the record low sea ice extents so far this year.”