While doing research 12 or 13 years ago, I met Jim Hansen, the scientist who in 1988 predicted the greenhouse effect before Congress. I went over to the window with him and looked out on Broadway in New York City and said, “If what you’re saying about the greenhouse effect is true, is anything going to look different down there inAnd the reality after 23 years?2040 years?” He looked for a while and was quiet and didn’t say anything for a couple seconds. Then he said, “Well, there will be more traffic.” I, of course, didn’t think he heard the question right. Then he explained, “The West Side Highway [which runs along the Hudson River] will be under water. And there will be tape across the windows across the street because of high winds. And the same birds won’t be there. The trees in the median strip will change.”
According to the actual data, after 23 years, we’ve seen about a 2.5 inch rise. There’ s still a very long way to go to ten feet to cover the West Side Highway there.So what are the current predictions?
To reach the goal he predicted in 1988, Dr. Hansen needs to motivate the sea to do his bidding, he’s gonna have to kick it in gear and use a higher octane driver if he’s going to get there
IPCC (2007) projected sea level rise by the end of this century of about 29 cm (midrange 20-43 cm, full range 18-59 cm). These projections did not include contributions from ice sheet dynamics, on the grounds that ice sheet physics is not understood well enough.The "midrange" estimate of about one foot by 2100 is basically the natural rate of the sea level rise – we are still seeing the effect of the end of the last ice age.
So what does one do, when the predictions of immediate doom fall through? Postpone the apocalypse.
Under BAU ["Business As Usual"] forcing in the 21st century, the sea level rise surely will be dominated by a third term: (3) ice sheet disintegration. This third term was small until the past few years, but it is has at least doubled in the past decade and is now close to 1 mm/year, based on the gravity satellite measurements discussed above. … As a quantitative example, let us say that the ice sheet contribution is 1 cm for the decade 2005–15 and that it doubles each decade until the West Antarctic ice sheet is largely depleted. That time constant yields a sea level rise of the order of 5 m this century.Neat. Exponential sea level rise! 5 meter by the end of this century! You don't see it now, but it will be horrible – because we know.
(Look at the update of Willis Eschenbach a bit down the page too)
[Update] From IPCC's AR5 chapter 11 summary:
We have low confidence that over the next few decades there will be global and regional increases in the intensity of the strongest TCs, and the decrease in global TC frequency as is projected for the end of the 21st century in response to increasing greenhouse gases.