Years of Rising Temperatures on Earth in 30 Seconds

The average global temperature for 2015 was the warmest since record-keeping started in 1880, breaking the mark set past year by a full quarter degree, according to the latest climate update from NASA and NOAA.

During the year, all but two months had record high temperatures, and the five highest monthly departures from average for any month on record all occurred during 2015, according to NOAA. One U.S. climate scientist told the New York Times that the odds of back-to-back records, of 2014 and 2015, are remote, and would only make sense if the planet were warming inexorably. According to the agencies, average global temperatures have increased 1.8 degrees F since the late 19th century and are 1.62 degrees F above the 20th century average.

A National Climate Assessment study of tree rings, ice cores, and corals showed that temperatures over the last several decades are “clearly unusual”, and warmer than any time in the last 1300 years, “or longer”.

Although this year’s El Niño shares some responsibility for the higher temperatures, NASA scientists state that 2015 temperatures are the result of a long-term trend.

Both Schmidt and Karl emphasized that rising greenhouse gas emissions are responsible for record temperatures, independent of weather cycles such as the current warming trend in the central Pacific.

Because of the wide margin over 2014, NASA calculated that 2015 was a record with 94 percent certainty, more than double the certainty it had previous year when announcing 2014 as a record.

The globally-averaged land-only surface temperature was 2.39°F (1.33°C) above, and sea surface temperature were 1.33°F (0.74°C) above the average. For example, the 2015 annual mean temperature for the contiguous 48 United States was the second warmest on record.

“In December and recent months in the autumn, records were broken by a substantial margin — much stronger than what we had seen earlier in the year”.

El Niño, a warming of the Pacific Ocean that is credited with triggering atmospheric conditions that suppress Atlantic hurricanes, also moves the jet stream across the USA further north, blocking winter blasts from making it as far south as Florida.

The fact that 2015 was going to break records had been heavily trailed by research agencies all over the world.

“Is there any evidence for a pause in the long-term global warming rate?” Through 2015, a warming El Nino was in operation.

And it’s likely to happen this year, too. Schmidt, Karl and others said there’s a better than even chance that this year will pass 2015 as the hottest year on record, thanks to El Nino.

“2015 will be hard to beat, but you say that nearly every year and you get surprised”, said Victor Gensini, a meteorology professor at the College of DuPage outside of Chicago.