Not to detract from the trend toward an ice free Arctic. It seems a lot of people are guessing that will happen by 2017, 2020, and up to 2040. The rapid release of 50+GT of methane could very well come before total Arctic Icecap loss. It won't last long then, and then Antarctic will also go ice free in a flash geologically as the general ocean warming reaches the upper hydrate deposits.
Thought has been given to some reflective geo-engineering. Proven impractical and unaffordable where needed most.
Younger people will experience the ice free Arctic, the 50GT rapid CH4 release with rapid temperature rise. Survivors' kids will experience the ice free Antarctic with 70 meter ocean level rise, and some of the rest of the 1000+GT of CH4 explosively releasing, before it is too hot to survive, except underground. Then their grandkids will see the surface become Unsurvivable, as the heat builds up underground, too. Toward a baked planet with no life. Unless a Power greater than humans changes the trend.