The word that no one dares mention, for fear of tripping over their own tongues : paleoclimatology, the study of Earth’s Climate history, on the long scale.
The presentations from the 4 Degrees conference are being uploaded to the Internet website :-
At the top of this page is an image from the talk from Professor H. J. Schellnhuber CBE :-
If you look back in time at various stable states of the Earth, and make the crude first-order assumption and connect the dots to make a line, it shows we could be in for around 50 metres of sea level rise, after the Earth system has done stabilising to a doubling of atmospheric Carbon Dioxide levels.
That, at least, should make you sit bolt upright in your chair and stop snoozing.