Well, once the CO2 is in the air and stays there, the warming will happen. Then hundreds of years later the threshold is passed and then even removing it from the air (something we can't do) won't help anymore.
Once we've emitted enough CO2 to reach 2 degrees warming, it will almost certainly happen that all the ice melts. And there's a point where that will be certain, even if we learn how to remove all CO2 we emitted from the atmosphere. Is how I read it.
The ice on this island is enough to cause about 7m of global sea level rise on its own, iirc.
Once we've emitted enough CO2 to reach 2 degrees warming, it will almost certainly happen that all the ice melts. And there's a point where that will be certain, even if we learn how to remove all CO2 we emitted from the atmosphere. Is how I read it.
The ice on this island is enough to cause about 7m of global sea level rise on its own, iirc.