Sea levels rising, responses needed on land

New sea level science suggests the oceans will rise faster this century than previous predictions have suggested.

The suggested rise puts most beach parks under water, along with coastal roads, and, of course, Waikiki.

(Image: An Hawaiian coastline.)

The United Nations Intergovernmental Panel on Climate Change suggested oceans could rise a couple of feet, give or take, by 2100. But that estimate entirely excluded the impact of two immense reservoirs of frozen water—Greenland and Antarctica.

It left them out because the science of determining how they might melt and impact ocean levels was not clear.

Science is now slowly gaining clarity, and for coastal places like Hawai'i, things don't look good.

A recent study by scientists from the University of Alaska Fairbanks found that the Greenland ice sheet is contributing a quarter of all sea level rise over the past 13 years, and that sea levels are rising 50 percent faster than the average of the last century. This scientific paper by Sebastian H. Mernild, Glen E. Liston, Christopher A. Hiemstra, Konrad Steffen, Edward Hanna, and Jens H. Christensen, in the journal Hydrological Processes, is entitled “Greenland Ice Sheet surface mass-balance modelling and freshwater flux for 2007, and in a 1995-2007 perspective.”

Researchers are predicting that the East Coast of the United States could face by 2100 sea level rise of six feet. Presumably Hawai'i will have levels somewhere close to that. But how to respond?

“Recognition of the need for an adaptive approach necessarily counsels governments to implement initial adaptation measures that will be beneficial to coastal communities regardless of how far the oceans encroach and how fast they do so,” wrote Florida State's Robin Kundis Craig in a paper in the Widener Law Review. The abstract is available here: http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1119563#.

Craig said coastal areas need special planning approaches.

There are two problems, Craig says. One, we don't have planning systems capable of responding to a crisis that builds over multiple decades and centuries. And two, the science may tell us it's coming, but it can't yet be clear about how high the sea will rise when.

If planners can't bring themselves to actually do land use planning in response to the threat, at least they could do some public health planning, she argues.

“Taking a public health approach to sea-level rise can provide governments and planners with immediately implementable and no regrets adaptation measures that will be beneficial to coastal communities regardless of the eventual actual impacts of sea-level rise in particular areas of the country,” Craig wrote.

She cites three examples: to ensure drinking water supplies will be protected in a rising sea level environment; protecting medical infrastructure to address disease exposure problems; the potential that ocean water will be contaminated by toxic materials from the nearshore land.

A Hawai'i example is University of Hawai'i coastal geologist Chip Fletcher's assertion that during high tides in a high sea level environment, coastal sewer lines could be compromised.

It's just another caution.

© Jan TenBruggencate 2009