Hottest Year Slideshow

How do we know it's the hottest year on record anyways? There are four major meteorology centers around the world that crunch the numbers each year. As the graphic above shows, there are some slight discrepancies in some individual years based on how they process the data but it's clear they're all in agreement about the trend and the record heat in 2014. Credit: NASA Earth Observatory
You may have heard of something called the global warming slowdown or hiatus that refers to what's happened to global temperatures since a major El Niño in 1998. The reality is that temperatures have kept rising since then and there's been no significant change in the trend since 1998 according to Gavin Schmidt, who runs NASA Goddard Institute for Space Studies. Credit: Gavin Schmidt
El Niño can increase the global average temperature while La Niña can decrease it, but no matter the phase of the climate phenomenon, global temperatures have risen. The graphic shows annual average temperatures in El Niño, La Niña and neutral years and all are getting warmer. What makes 2014 stand out in particular is that the record heat came in a year with no El Niño. NASA Earth Observatory
So where was the heat in 2014? Well, it turns out everywhere except the eastern U.S. The global temperature map for the year released by NOAA shows that plenty of areas experienced record heat, including Europe and the western U.S. while warmer-than-average conditions prevailed in lots of other locations. The eastern U.S. is a lonely dark blue island in a sea of mostly red. Credit: NOAA
And just in case the NOAA visualization doesn't make it clear, take a look at how the Japan Meteorological Agency shows 2014. The cold over the eastern U.S. and warmth in just about every other location comes through loud and clear. Credit: JMA