According to NASA and NOAA scientists, 2015 was the warmest year ever for global land and ocean surfaces, dating all the way to 1880.
And it's not just American scientists who are reporting that last year was the warmest on record, British scientists reported that it was the warmest year since 1850, and Japanese scientists reported that it was the warmest year since 1891.
Keep in mind, 2014 had set the previous record for global surface temperatures, and 2015 just beat that record by a
longshot.
Part of what's going has to do with an unusually warm Pacific Ocean due to an El Nino that's going on right now, but that doesn't explain it all.
As Dr. Michael Mann explained to the
New York Times, if the global climate weren't warming, the odds of setting two back-to-back record years would be about one chance in every 1,500 pairs of years.
He added though, that because the planet is warming, the odds of setting back-to-back record years is really closer to one in ten now.
The really scary part though, is that there's good evidence that this is nothing compared to what's to come.
This graph shows how global temperatures have historically, for over 400,000 years, tracked with carbon dioxide and methane levels in the atmosphere.
There's a clear relationship between increases in atmospheric carbon dioxide and methane, and warmer temperatures in our planet's history.
On the other hand, during cooler periods in Earth's history, the "Ice Ages", the atmosphere contained lower concentrations of methane and carbon dioxide.
But, as this chart shows, those natural cycles were disrupted sometime around 10,000 years ago, right around the time that the last ice age ended.
Just as William F. Ruddiman argued in a
paper from 2003, even though humans hadn't industrialized, we had already started having a major impact on the Earth's atmosphere and its natural cycles as far back as 8000 years ago.
And that makes sense, because 8000 years ago is about the time that early agriculture appeared in Eurasia and humans started clearing, and burning, forests to make more space for agriculture and human settlements.
