We need remember we have already had 0.8c of that rise since the start of the industrial revolution and, over the past 15yrs, have seen a significant change to the northern hemisphere albedo over summer here. I worry that the remaining 0.7c will very quickly be attained as the planet responds to the albedo flip and the extra energy, once employed on ice/snow melt ( that is also free to do other tasks in the climate now) will be plenty enough to drive a small scale 'abrupt climate shift' over the coming decade?
I think folk also need to remember that our carbon cycle has a large portion that is currently hibernating under the two great ice sheets and so any further hike in temp from the loss of the permafrost also attacks these bodies re-animating the carbon there?
I get the feeling that we must entertain the notion that ,over time, we will have brought about the total deglaciation of the planet?