As it gets warmer the amount of Tundra will become larger.
Canada's Tundra stores more then half of the World's methane the singular worst of the global warning gasses. Add to this the millions upon millions of tonnes of Carbon Dioxide that is frozen into that same Tundra.
If we do not arrest global warning it will be the end of civilization as we know it. And, its not going to take centuries to accomplish this dubious end! A few years should put us around the corner!
The significance of what is happening will effect the world at large and cannot be understated.
In addition to this pressing evidence there is still more proof on the earth it's self!
Earth travels in an elliptical orbit. Right now, we are moving away from the sun right on schedule but, instead of cooling down as we should be, we are warming up. We either get a handle on this or totally loose our glaciers and associated potable water on the short term.