"How could 2014 have been the warmest year ever?"
"Well, it’s official. 2014 was the warmest year on record. That’s what a group of scientists at NASA and NOAA concluded after looking at temperature data for the past year from around the globe. Reading that right now, you might be in shock. January of 2015 has been unbearably cold for much of the United States. And let’s not forget that the winter of 2014 was the winter of the dreaded polar vortex!
. How could such a year possibly have been the warmest? . It's all about the Big Picture!
You can’t just look at one area and one time and judge what the world is doing as a whole. Yes, there was the polar vortex. But many areas also broke records for hottest temperatures, too. When you average everything, it turns out that 2014 was warmer than any other year for which we have this kind of data.
But the entire year of 2014 is just one tiny piece of data when it comes to climate change. Climate happens over long periods of time—generally averaged over 30 or more years!
That’s why its important not to get weather (like a cold January or what is happening right now) and climate (like an overall trend over a long period of time) mixed up."