For a while now, scientists have been talking about “global warming”, saying that the earth’s temperature is rising at an alarming rate. They’ve been talking about melting icebergs, rising sea levels, and a changing climate. But it’s since been so cold lately, global warming can’t be real. Right?

Wrong.

Let’s zero in on the melting of the sea ice in the Arctic, which is caused by the ever-increasing amount of greenhouse gases in the atmosphere that warm up the Earth.

This loss of sea ice is correlated to a change in the path of the Jet Steam, an air current that influences climate across the planet. The loss of ice weakens the winds that make up the Jet Stream, making it take a curvier, more winding path. This allows certain areas to get colder, even as the Earth warms up overall.

The Jet Stream usually goes straight across the Northern Hemisphere and acts as the boundary between cold and warm air. Lately though, the Jet Stream has been looping around in what’s called a negative phase. Instead of going straight across the United States, for example, it loops up over the western US and curves back down to cover the East Coast in a cold spot.

As a result, places that normally have cold weather have been unusually warm: think of Alaska, which recently broke the record for the state’s warmest January temperature at 62 degrees Fahrenheit. Some towns reached temperatures that were 40 degrees above normal. This unusual warmth has caused extreme avalanches as the snow melts. Greenland was also abnormally warm in January, and in Sochi, Russia, artificial snow had to be brought in because too much of the natural snow had melted. On the other hand, the East Coast of America has been experiencing long, cold winters and lately seems to be trapped in a cold spell.

Another effect of the melting sea ice is that more ocean water is exposed to the sun’s rays in the warmer months. This open water evaporates much more easily than the ice would, and more water vapor is moved into the atmosphere. The Jet Stream then moves this water vapor further south, where it turns into snow.

This cold, snowy weather has prompted some to claim that global warming is all a hoax because here in the Northeast, it’s freezing!  But when seen in the context of the bigger picture, it’s clear that this is just another crazy effect of global warming.

http://www.scientificamerican.com/article/earth-talk-getting-fresh/

http://www.treehugger.com/climate-change/why-it-so-cold-if-earth-warming-video.html

http://www.scientificamerican.com/article/recent-snowy-winters-rapid-melting-arctic/

http://thinkprogress.org/climate/2014/02/08/3266731/hot-alaska-cold-georgia-polar-vortex/#

Greene, Charles H. “The Winters of Our Discontent.” Scientific American.