Independent climate analyses by NASA and by the National Oceanic and Atmospheric Administration (NOAA) have both concluded that 2016 was the hottest year on record since 1880, the year scientists first started keeping track of global temperatures.
Average temperatures on the planet were 1.78 degrees Fahrenheit (0.99 degrees Celsius) higher last year than what they were in the mid-20th century.
“That doesn’t sound like a lot, but when you take that, and you average it all the way around the planet, that’s a big number,” said Deke Arndt, chief of monitoring for NOAA’s National Centers for Environmental Information in Asheville, North Carolina.
“Some part of every continent, and some part of every major ocean basin was warmest on record,” he noted.
A NASA statement pointed out that 2016 was the third consecutive year to set a record for the hottest global surface temperatures.
Additionally, eight months of the year set their own records for being the hottest of that month since record keeping began.
According to NASA, the warming weather pattern known as El Nino was responsible for a 0.2 increase in temperatures worldwide, mostly in the year’s first four months.
Data that went into both agencies’ analyses came from six separate processes of monitoring temperatures worldwide, all of which showed similar levels of warming.
The space agency’s data came from 6,300 weather stations, ships and buoys, and Antarctic research stations, which together measure both land and ocean temperatures.
Scientists in both agencies also studied data gathered by satellites and weather balloons, which monitored temperatures in different parts of Earth’s atmosphere.
The year was especially bad for the Arctic, which is warming about twice as fast as the rest of the globe. Warmer temperatures melt its ice and snow, which reflect sunlight back into space, producing water, which absorbs rather than reflects that heat, causing a vicious cycle.
“We don’t expect record years every year, but the ongoing long-term warming trend is clear,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies in New York.
While temperatures increased in Earth’s upper atmosphere as far as 40,000 feet (12,000 meters), they decreased in its lower stratosphere, a phenomenon scientists attribute to lower ozone levels and increased carbon dioxide levels in the latter.
These atmospheric changes, along with increasing ocean temperatures, indicate most of the warming is caused by the release of greenhouse gases by human activity, scientists stated.