2015 Was the Hottest Year on Record by a Huge Margin

The uptick between 2014 and 2015 was the most dramatic increase between two consecutive years since 1998.

NASA 2015 climate map. Video: Scientific Visualization Studio/Goddard Space Flight Center/YouTube

It's official: 2015 was the hottest year on record, according to a joint announcement from NASA and NOAA. The news is not exactly a surprise, given that climate scientists projected the year would claim this ominous title as early as last August, which was, if you'll recall, the most sweltering month on record.

What is shocking, however, is how thoroughly 2015 trounced the previous record set by 2014. NASA's analysis estimated that global temperatures last year jumped about 0.23 degrees Fahrenheit, or 0.13 degrees Celsius, compared to 2014, while NOAA's findings are even worse, indicating a rise of 0.29 degrees Fahrenheit, or 0.16 degrees Celsius.

That may not sound like a huge shift on its face, but it is extremely worrisome when viewed as a trend. Indeed, it is the largest temperature increase recorded between two consecutive years since 1998.

One of the major contributors to 2015's record-breaking warmth was the resurgence of the El Niño warming cycle, which boosted global temperatures for most of the year. But while this periodic weather pattern is partly to blame for bringing the heat, the central problem remains ongoing climate change as a result of human activity, according to NASA and NOAA.

"2015 was remarkable even in the context of the ongoing El Niño," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies, in a statement. "Last year's temperatures had an assist from El Niño, but it is the cumulative effect of the long-term trend that has resulted in the record warming that we are seeing."

This record warming goes hand in hand with all the freak weather patterns and natural disasters endured by communities around the world last year. Spring heat waves in India killed an estimated 2,500 people. Megadroughts and wildfires are becoming the norm, especially for vulnerable regions such as California. Coral bleaching is devastating marine life, and nations are slipping under rising sea levels. Climate change has been widely implicated in several major social upheavals, including the Syrian refugee crisis.

What's more, 2016 is already projected to be even hotter than 2015, suggesting that we may be locked into an intensifying annual pattern of record-breaking temperatures over the near term.

The forecast for the long term is, of course, harder to read. But it bears mentioning that though 2015 may have been the hottest year on record, it was also an encouraging year for climate change activism. Global attempts to reach substantive agreements, such as the recent Paris talks, continue to fall far short of what is necessary, but at least they demonstrate commitment to international participation on the issue.

Meanwhile, climate change has become such a hot political button that even some Republicans are beginning to take it seriously, though they remain a minority. Concern over rising temperatures has been expressed in everything from tech startups to passionate protests. Perhaps most significantly, President Obama killed the Keystone XL pipeline proposal, setting a clear message that there is real political will to phase out fossil fuels.

This rising tide of populist concern over the warming planet is not likely to stop 2016 from overtaking 2015 as the hottest year on record, but it could prevent further disasters down the line. If there's one New Year's resolution we should all stick to, it's continuing this fight for a sustainable future on our planet.