1998 was the hottest year on record. 2005 was the hottest year in more than a century. 2010 was just as hot. 2014 was the hottest year on record.
And now we’ve set a record once again — 2015 was Earth’s warmest year since record-keeping started in the 1800s. That conclusion comes from three separate analyses released Wednesday, which you can see in the chart below.
One measure is from a National Oceanic and Atmospheric Administration analysis, another from NASA, a third from the U.K.’s Met Office (previously known as the Meteorological Office), and finally NOAA’s raw data without adjustments to account for technical issues. “Regardless of whether you correct the data or not, if you just plot the raw data, you still get a record in 2015,” said Thomas Karl, director of NOAA’s National Centers for Environmental Information, in a press briefing Wednesday.
In case three data sources in agreement weren’t enough to convince you, the NOAA, NASA and U.K. data mirrors the findings of other groups, including the Japan Meteorological Agency and Berkeley Earth, an independent analytic group created to investigate the concerns of climate skeptics.
“There’s no evidence of any change in the long-term trend,” said Gavin Schmidt, head of NASA’s Goddard Institute for Space Studies, during the press briefing. It just keeps getting hotter. As the following chart illustrates, global temperatures have been on a decades-long upward trajectory.
January and April were the only months in 2015 that did not produce record global average temperatures. As El Niño kicked in, the warming became more pronounced, with October, November and December far exceeding the previous global temperature records.
It’s quite likely that 2016 will be even hotter. Past trends have shown a pronounced warming about four to six months after the start of an El Niño like the one that began last year. Because of this delay, 2016, which Gavin said began with “a very strong El Niño,” is expected to be an exceptionally warm year — “perhaps even another record,” he said.
But El Nino is only a small part of the story. Global warming remains the major driver of rising temperatures, Gavin said. “There is no evidence that that long-term trend has slowed, paused, or hiatused at any point in the last few decades,” he said.
For some who reject the conclusions of climate change scientists, such as GOP presidential hopeful Ted Cruz, these measurements are not enough. These skeptics have pointed to satellite-based measurements as evidence that warming isn’t as large as ground-based measurements imply. But Carl Mears, a senior scientist for Remote Sensing Systems, told The Associated Press that satellite measurements have five times the margin of error that ground-based measurements do and that measurements taken at the Earth’s surface are more important for their influence on humans and our environment.
Both land and satellite-based data shows warming, but what’s happening on the ground is especially urgent, Karl said. “The reason why we emphasize and regularly record what’s going on at the surface is that’s where we live, that’s where we work, that’s where we grow our food.”