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Thursday, 6 March 2008

Global warming and endengered species

The Preservation Predicament

29, 2008

Conservation organizations that work to preserve biologically rich landscapes are confronting a painful realization: In an era of climate change, many of their efforts may be insufficient or beside the point.

Some scientists say efforts to re-establish or maintain salmon runs in Pacific Northwest streams will be of limited long-term benefit to the fish if warming makes the streams inhospitable. Others worry about efforts to restore the fresh water flow of the Everglades, given that much of it will be under water as sea level rises. Some geologists say it may be advisable to abandon efforts to preserve some fragile coastal barrier islands and focus instead on allowing coastal marshes to migrate inland, as sea level rises.

And everywhere, ecologists and conservation biologists wonder how landscapes already under preservation will change with the climate.

“We have over a 100-year investment nationally in a large suite of protected areas that may no longer protect the target ecosystems for which they were formed,” said Healy Hamilton, director of the California Academy of Sciences, who attended a workshop on the subject in November in Berkeley, Calif. “New species will move in, and the target species will move out.”

As a result, more and more conservationists believe they must do more than identify biologically important landscapes and raise money to protect them. They must peer into an uncertain future, guess which sites will be important 50 or 100 years from now, and then try to balance these guesses against the pressing needs of the present.

No one is suggesting that land conservation done so far has been a wasted effort. Many argue that preserved areas will contribute immensely to ecosystem resilience as the climate changes. For example, environmentally intact salmon streams will undoubtedly be useful if new species move into them. And even if much of the Everglades is lost to a rise in sea level, preserving the rest will be crucial for maintaining fresh water supplies in South Florida, said Dan Kimball, superintendent of Everglades National Park.

Mr. Kimball said that if the Intergovernmental Panel on Climate Change was right, and sea levels rose as much as two feet by the end of the century, up to 50 percent of the Everglades’s fresh water marsh “would be transformed into a salt water system.” But, he said, restoring the fresh water flow might “create a fresh water barrier, hopefully, and keep the rising seas at bay.”

The Everglades ecosystem is full of uncertainties, Mr. Kimball said, explaining that “we don’t know the rates of change.” If seas rise faster than the climate panel predicted in its report last year, which many scientists regard as likely, mangroves crucial to the health of the glades could be submerged. But “if it’s slow,” he said, “the mangroves could gather sediment and actually build landform” — something that he said happened after Hurricane Wilma washed over the vast wetland in 2005.

This kind of uncertainty is widespread. For example, Dr. Hamilton said that on the Northern California coast, fog has an influence on natural systems. But “none of our climate models can tell us what is going to happen with fog,” she said. “So we are facing profound uncertainties about how our coastal ecosystems are going to look.”

“It’s a real dilemma,” said David S. Wilcove, a conservation biologist at Princeton. “What you are trying to do is balance the urgent needs of the present — the ongoing destruction of habitats that species need now — with the urgent needs of the future — places where they may end up if they are able to move in response to changing climate.”

Mr. Stanley said that to cope, the Nature Conservancy was adopting new strategies, which include identifying for preservation potential refuges against changing climate, landscapes that have had relatively stable vegetation over thousands of years, and removing or reducing other stresses on the landscape, particularly activities by people.

Other plans are to search for resilient species or subspecies that can cope with a warming trend. For example, conservancy scientists looked at which reefs did best when Caribbean waters warmed in an El Niño event in the late 1990s. Resilient strains could be used to restore damaged reefs.

Some scientists say it may be necessary one day to move plants and animals into new areas and are working to devise theoretical frameworks for deciding when, how or whether to act.

“What you are basically doing is moving species to places where they do not occur but where you think they will be suitable. But we often get into trouble translocating species for all kinds of unexpected reasons that come up.”

Coastal ecosystems are likely to be the first to pose difficult conservation problems, as sea level rise inundates protected areas or makes them more vulnerable to damage in storms.

For example, Asbury H. Sallenger, an oceanographer at the United States Geological Survey and an expert on coastal hazards, said conservationists had been considering massive sand-pumping efforts in hopes of restoring a bird habitat on the Chandeleur Islands, barrier strands off the coast of Louisiana that were severely damaged in Hurricane Katrina and other storms. But with sea level rise accelerating, Dr. Sallenger said in an e-mail message, “there is reason to believe these islands may disappear much more quickly than we thought just a few years ago.”

As a result, Dr. Sallenger said, the agency was working to estimate the projected lifespan of the islands, should they be rebuilt to their configuration of the late 1990s. “In other words,” he said, “will the time gained be worth it.”

But while many realize that ocean beaches are threatened by climate-related sea level rise, they do not understand that coastal wetlands — crucial nurseries for fish and shellfish — are at least as vulnerable, much less likely to be preserved and, in many areas, penned in by development and unable to migrate inland, as they would naturally as seas rise.

Some conservationists advocate triage, accepting that some ecosystems, like coral reefs, may not survive in a warmer world, and putting their efforts elsewhere. Others, like Mr. Stanley at the Nature Conservancy, are not ready to give ground. “I don’t think those analyses take into account the resilience,” he said. “We are less focused on triage and more focused on resilience.”(source)

My comment: I know this one is pretty long, but I found it interesting to see what people are doing to preserve endangered species. And there are many specific stories that opponents of Global Warming like to ignore.

And here's one very interesting blog I found on New Scientist which compare the arguments against abolition of slavery in the 19th century with those against Global Warming. Funny and enlightening...The link

What are the comments and how similar are they really? I'll let you judge for yourself. The full text of the paper is available here, though you may have to pay to access it.

Here is a sample:

On the uncertain benefits of the abolition of slavery:

"...the course of [the abolitionists] whose precipitate and ignorant zeal would overturn the fundamental institutions of society, uproar its peace and endanger its security, in pursuit of a distant and shadowy good, of which they themselves have formed no definite conception."
(in: Simms 1852, p 98)
Davidson compares this to the words of current US congressmen who mention the "inconclusive and often contradictory" nature of climate science. On the cost of change:
"Their [the slaves'] value, at $400, average, (and they are now worth more than that,) would amount to upwards of 900 millions. The value of their annual increase, alone is 24 millions of dollars; so that to free them in 100 years, without the expense of taking them from the country, would require an annual appropriation of between 33 and 34 millions of dollars. The thing is physically impossible."
(James Henry Hammond, senator of South Carolina, 1836)
Davidson compares this to the often cited concerns that limiting greenhouse gas emissions will harm the US economy. The crux of Davidson's argument is that the US economy now relies on oil in much the same way as the economy of the Southern States relied on slaves 200 years ago – as a key source of energy.

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