By Seth Borenstein
WASHINGTON — Earth’s persistent record 2016 heat is now dancing near levels that a world agreement is trying to avoid, federal scientists said.
The National Oceanic and Atmospheric Administration said Tuesday that globally , June was the 14th straight record hot month, with Earth averaging 61.52 degrees (16.4 degrees Celsius). That is 1.62 degrees (0.9 degrees Celsius) warmer than average and a shade above the record set in 2015. The last month Earth wasn’t record hot was April 2015.
NOAA Tuesday also warned about excessive heat for much of the United States this week, especially at the end of the week, when parts of the East could be flirting with triple digit temperatures.
Scientists said records keep falling because of a combination of man-made global warming and the natural El Nino, a periodic warming of the Pacific that changes weather worldwide and heats the globe. But El Nino ended a couple months ago and the record heat — and record melting of Arctic sea ice — has stuck around.
What’s really got federal scientists’ attention is the record warm first half of 2016, which comes after two record hot years.
NOAA said the first half of 2016 was 0.36 degrees (0.2 degrees Celsius) warmer than last year’s record.
NASA chief climate scientist Gavin Schmidt said the first six months of the year were not just the warmest on record, by far, but 2.3 degrees warmer (1.3 degrees Celsius) than the last two decades of the 19th century. But more importantly, he said 2016 so far is about 2.7 degrees warmer (1.5 degrees Celsius) than pre-industrial times.
That 1.5 degrees Celsius mark is key. A December 2015 international pact to control global warming set a goal of avoiding 1.5 degrees Celsius warming above pre-industrial levels. And the agreement says if Earth can’t limit global warming to 1.5 degrees, at least it should limit it to 2 degrees (3.6 degrees Fahrenheit) above pre-industrial levels.
Because El Nino is a factor — Schmidt figured about 40 percent of the reason 2016 is hotter than 2015 is due to El Nino — 2017 will likely be a bit cooler than 2016. When scientists look at long-term warming since pre-industrial times they don’t look at one year, but it’s still a pretty noticeable threshold, Schmidt said.