Blackadder was keeping me/us honest in the comments of my previous post on adapting to climate change. In particular, he thought I was being flippant in saying people could just move inward if sea levels started rising. It devolved (among him and other commenters) into an argument about the relatively pace of the increase, leading Blackadder to say:
Take a concrete example: New York City. If sea levels rise by several meters, then potentially much of it could end up under water. Granted, this would happen over the course of decades, but I’m not sure how that helps much. Saying “we’ll just wait for the individual buildings to wear out and then relocate them to Cleveland” is not a workable solution.
Fortunately, the “settled science”–as codified in the IPCC AR4–gives projections about sea level rises under various emissions scenarios, and they are nowhere close to what Blackadder mentioned above. Of course, Blackadder wasn’t saying he was accurately reproducing the best-guess estimates, but it is important I think for people to realize that what we are told is the “consensus” has this to say:
==> In the lowest emission scenario, sea levels in the decade 2090-2099 will be 18cm – 38cm higher than they were in the period 1980-99.
==> In the two middle emission scenarios, sea levels in 2090-99 will be anywhere from 20 – 48 cm higher.
==> In the highest emission scenario, sea level rises in 2090-99 will be anywhere from 26cm – 59cm.
Of course, it’s possible that sea levels will rise by several meters over the course of a few decades. But the latest IPCC report projects that in the middling emission scenario, over the next nine decades sea levels will rise about one-third of a meter.