DO WE REQUIRE CATASTROPHE?

INCREMENTS OR CATASTROPHE
It is interesting how quickly the discussion of climate change gets anchored around a particular topic. Sometimes it is, "what car should I buy?" Here we have moved to sea level rise, geo-engineering and island cities along the Atlantic Coast. In "Climate Change 2007" the observed sea level rise is divided up between its sources: thermal expansion of the ocean, melting of glaciers and ice caps, and melting of the Greenland and Antarctic ice sheets. The report considers the measured sea level rise between 1961 and 2003 and separates out the last 10 years, 1993-2003. Two facts that I note: 1) the largest part of sea level rise, so far, is from thermal expansion of the ocean. The ocean has absorbed a lot of heat, which can be measured to a depth of 3000 meters. Heating water causes it to expand. 2) The rate of the sea level rise is significantly larger in the last ten years of the record. This, again, is a set of correlated observations, consistent with the predictions of a warming climate--another "fingerprint."

In 2003 the Government Accounting Office produced a report on the vulnerability of coastal "Alaskan Villages" to flooding and erosion. There are already villages moving to higher ground, adapting to higher temperatures. This links to a summary from the American Association for the Advancement of Science that discusses the situation in Shismaref, Alaska. Alaska is at high northern latitudes; it is the part of the United States which sits at a place where both the observed and predicted temperature changes are large. (The AAAS link has died since original post. Text is here.)

The situation in Alaska, today, raises many questions. There is the reality of the expense of moving long established communities--a cost which is not recovered by tangible economic benefit. This raises questions of ethics and liability. There is fact that some see benefit from the melting of the ice in the Arctic--the Northwest Passage would be realized--a potential new region of oil resources is opened for exploration--energy security. There are the highly publicized troubles of the polar bears and warming of the permafrost which impacts both ecosystems and the stability of existing roads and pipelines.

We have, here, the reality of warming and its impacts. From the point of view of economics, some could be viewed as losers, some as winners. This is the current incremental reality, and it will lead to development of adaptation strategies, lead to exposure of resilience of communities. Is it possible that rather than waiting for catastrophe, we can develop viable and extensible approaches that balance the conflicting pieces of our reality? Ideas?
ricky


Figure 1. From NOAA's Office of Oceanic and Atmospheric Reseach This figure shows temperature variability at a number of interior stations in the Alaskan forest.