Hansen has posted some important thoughts about sea level rise on his website. In particular, he has shortened his “Scientific reticence and sea level rise” paper and New Scientist has published it. The key conclusion:
[I]ce sheets will respond in a non-linear fashion to global warming — and are already beginning to do so. There is enough information now, in my opinion, to make it a near certainty that business-as-usual [emissions] scenarios will lead to disastrous multi-metre sea level rise on the century time scale.
This leads directly to his emissions strategy:
The global community must aim to restrict any further global warming to less than 1°C above the temperature in 2000. This implies a CO2 limit of about 450 parts per million or less. Such scenarios require almost immediate changes to get energy and greenhouse gas emissions onto a fundamentally different path.
Hansen also offers some useful thoughts about recent research on Greenland, and has been misunderstood by the media.
