Will island nations wash away?

Among the many consequences predicted for global warming are rising sea levels due to the melting of the polar ice caps and increases in the frequency and intensity of storm activity. Many environmentalists today regard the islands of the Pacific as sensitive indicators:

Rising Waters: Global Warming and the Fate of the Pacific Islands, an hour-long documentary that aired on PBS this past Earth Day, presented a picture of island nations threatened by eroding shorelines, inundated crop fields and poor fishing harvests.

Climatologists have predicted global warming will melt the polar icecaps, causing sea levels to rise more than 25 feet over the next century and submerging Pacific islands and coastal areas.

Over the past decade, Pacific islands have been buffeted by a series of severe storms, accompanied by unusually intense episodes of the El Nino-Southern Oscillation Phenomenon (ENSO), a periodic fluctuation in sea temperature in the Pacific observed since the last century.

However, it remains unclear whether these events have anything to do with global warming. In fact, a 2001 report from the U.N.'s Intergovernmental Panel on Climate Change (IPCC) does not confirm rampant fears about the effects of global warming.

According to the report, model projections suggest no clear trend in tropical cyclones, so it is not possible to state whether the frequency, intensity or distribution of the storms will change.

The IPCC discerns no significant trends in the extent of Antarctic sea-ice since 1978, when reliable satellite measurement began, and found that sea levels have risen at roughly the same rate for 100 years – 2 millimetres per year.

At the other pole, there is no evidence from satellite records that the air above the Arctic has warmed substantially.

Under the worst-case scenario now envisioned by the IPCC, the oceans should rise no more than a foot over the next century, based on the assumption that sea levels will increase approximately 5 millimetres per year, give or take 3 millimetres – in other words, the rate of rise may not change at all.

Source: Kevin Shapiro, Too Darn Hot? Commentary, June 2001.

For text of new National Academy of Sciences Global Warming report http://books.nap.edu/books/0309075742/html/

For more on Global Warming http://www.ncpa.org/hotlines/global/gwhot.html