The Arctic is in a death spiral.The top of our world is____1____up faster than anywhere else on the planet,____2____new records for the speed and area of ice melt.

We are on track this year to have one of the lowest summer sea ice coverage so far.It is a huge problem,____3____what happens in the Arctic doesn't stay in the Arctic. 

What's more, the Greenland ice sheet, which alone____4____enough water to raise global sea lev-els by 6 meters, is____5____.

The frozen Arctic soil and sediment, or permafrost, is melting,____6____more and more carbon dioxide and methane into the atmosphere.

This year, vast wildfires in the peatlands of Siberia have blazed for more than a month, and the Arctic warming is____7____havoc with weather systems in the northern hemisphere too.

But if you prefer to think simply in terms of money, the eco-nomic____8____of unmitigated Arctic warming by the end of this century was estimated to be $67 trilli-on. 

Climate____9____in the Arctic might be more necessary than it first appears because the region's death spiral is a feedback loop.

As the shiny ice melts, models and satellite images suggest we could get a sea ice-free summer any year now.When the ocean is exposed, instead of reflecting sunlight,the dark water absorbs____10____of the sun's heat.

Over the past 30 years, this change corresponds to a warming equivalent to a quarter of all the carbon dioxide released by human activity during that time.