Global Temperatures Are on Course for Another Record This Year

20 July 2016 | Mitigation

The world is on pace to set another high temperature benchmark, with 2016 becoming the third year in a row of record heat.

NASA scientists announced on Tuesday that global temperatures so far this year were much higher than in the first half of 2015.

Gavin Schmidt, the director of NASA’s Goddard Institute of Space Studies, said that while the first six months of 2015 made it the hottest half-year ever recorded, “2016 really has blown that out of the water.”

He said calculations showed there was a 99 percent probability that the full year would be hotter than 2015.

Dr. Schmidt said the world was now “dancing” with the temperature targets set last year in the Paris climate treaty for nations to limit climate change.

He attributed part of the rise in temperatures this year to El Niño, in which warming waters in the equatorial Pacific Ocean pump a lot of heat into the atmosphere.

El Niño is now ending, and water temperatures in the Pacific are dropping, which should lead in 2017 to lower but still historically high temperatures.

Average temperatures for the first six months of this year were about 1.3 degrees Celsius, or 2.3 degrees Fahrenheit, above the average in 1880, when global record-keeping began, and “quite close” to 1.5 degrees Celsius above preindustrial levels, Dr. Schmidt said in a conference call with other NASA scientists.

The warming in the first half of this year extended across all parts of the planet except for most of Antarctica, Dr. Schmidt said.

Warming was especially strong in the Arctic, where it had an effect on sea ice coverage.

Walt Meier, a scientist at NASA’s Goddard Space Flight Center, said that the geographical extent of the Arctic ice so far this year was the lowest for any half-year since satellite record-keeping began in 1979, largely because warm temperatures caused melting to begin as much as two months earlier than usual.

“It’s been an extreme beginning to the year for sea ice,” he said. It is not yet clear if this year will exceed the record for the lowest sea-ice extent, set in 2012, because most of the melting takes place later in the summer.

Warming of 1.5 degrees Celsius has special significance because at the Paris climate treaty in December, the world agreed to aim to limit the increase in average global temperatures to that amount above preindustrial levels.

Dr. Schmidt said that the Paris target referred to sustained temperatures over the long term.

“I certainly would not say that we have now gotten to that initial Paris number and are going to stay there,” he said. “But I think it’s fair to say that we are dancing with that lower target.”


Source: The New York Times