permaculture

[Niels <mudguard@gmail.com>]

In the backs of our minds I think we all know this!
The idea of getting the entire globe to cut its emissions to the level 
necessary is ludicrace.



Lawrence F. London, Jr. wrote:

> http://www.washingtonpost.com/wp-dyn/content/article/2006/01/28/AR2006012801021_pf.html
>
> Debate on Climate Shifts to Issue of Irreparable Change
>
> Some Experts on Global Warming Foresee 'Tipping Point' When It Is Too Late
> to Act
>
> By Juliet Eilperin
> Washington Post Staff Writer
> Sunday, January 29, 2006; A01
>
>
> Now that most scientists agree human activity is causing Earth to warm, the
> central debate has shifted to whether climate change is progressing so
> rapidly that, within decades, humans may be helpless to slow or reverse the
> trend.
>
> This "tipping point" scenario has begun to consume many prominent
> researchers in the United States and abroad, because the answer could
> determine how drastically countries need to reduce their greenhouse gas
> emissions in the coming years. While scientists remain uncertain when such a
> point might occur, many say it is urgent that policymakers cut global carbon
> dioxide emissions in half over the next 50 years or risk the triggering of
> changes that would be irreversible.
>
> There are three specific events that these scientists describe as especially
> worrisome and potentially imminent, although the time frames are a matter of
> dispute: widespread coral bleaching that could damage the world's fisheries
> within three decades; dramatic sea level rise by the end of the century that
> would take tens of thousands of years to reverse; and, within 200 years, a
> shutdown of the ocean current that moderates temperatures in northern
> Europe.
>
> The debate has been intensifying because Earth is warming much faster than
> some researchers had predicted. James E. Hansen, who directs NASA's Goddard
> Institute of Space Studies, last week confirmed that 2005 was the warmest
> year on record, surpassing 1998. Earth's average temperature has risen
> nearly 1 degree Fahrenheit over the past 30 years, he noted, and another
> increase of about 4 degrees over the next century would "imply changes that
> constitute practically a different planet."
>
> "It's not something you can adapt to," Hansen said in an interview. "We
> can't let it go on another 10 years like this. We've got to do something."
>
> Princeton University geosciences and international affairs professor Michael
> Oppenheimer, who also advises the advocacy group Environmental Defense, said
> one of the greatest dangers lies in the disintegration of the Greenland or
> West Antarctic ice sheets, which together hold about 20 percent of the fresh
> water on the planet. If either of the two sheets disintegrates, sea level
> could rise nearly 20 feet in the course of a couple of centuries, swamping
> the southern third of Florida and Manhattan up to the middle of Greenwich
> Village.
>
> While both the Greenland and the Antarctic ice sheets as a whole are gaining
> some mass in their cold interiors because of increasing snowfall, they are
> losing ice along their peripheries. That indicates that scientists may have
> underestimated the rate of disintegration they face in the future,
> Oppenheimer said. Greenland's current net ice loss is equivalent to an
> annual 0.008 inch sea level rise.
>
> The effects of the collapse of either ice sheet would be "huge," Oppenheimer
> said. "Once you lost one of these ice sheets, there's really no putting it
> back for thousands of years, if ever."
>
> Last year, the British government sponsored a scientific symposium on
> "Avoiding Dangerous Climate Change," which examined a number of possible
> tipping points. A book based on that conference, due to be published
> Tuesday, suggests that disintegration of the two ice sheets becomes more
> likely if average temperatures rise by more than 5 degrees Fahrenheit, a
> prospect "well within the range of climate change projections for this
> century."
>
> The report concludes that a temperature rise of just 1.8 degrees Fahrenheit
> "is likely to lead to extensive coral bleaching," destroying critical fish
> nurseries in the Caribbean and Southeast Asia. Too-warm sea temperatures
> stress corals, causing them to expel symbiotic micro-algae that live in
> their tissues and provide them with food, and thus making the reefs appear
> bleached. Bleaching that lasts longer than a week can kill corals. This fall
> there was widespread bleaching from Texas to Trinidad that killed broad
> swaths of corals, in part because ocean temperatures were 2 degrees
> Fahrenheit above average monthly maximums.
>
> Many scientists are also worried about a possible collapse of the Atlantic
> thermohaline circulation, a current that brings warm surface water to
> northern Europe and returns cold, deep-ocean water south. Hans Joachim
> Schellnhuber, who directs Germany's Potsdam Institute for Climate Impact
> Research, has run multiple computer models to determine when climate change
> could disrupt this "conveyor belt," which, according to one study, is
> already slower than it was 30 years ago. According to these simulations,
> there is a 50 percent chance the current will collapse within 200 years.
>
> Some scientists, including President Bush's chief science adviser, John H.
> Marburger III, emphasize there is still much uncertainty about when abrupt
> global warming might occur.
>
> "There's no agreement on what it is that constitutes a dangerous climate
> change," said Marburger, adding that the U.S. government spends $2 billion a
> year on researching this and other climate change questions. "We know things
> like this are possible, but we don't have enough information to quantify the
> level of risk."
>
> This tipping point debate has stirred controversy within the administration;
> Hansen said senior political appointees are trying to block him from sharing
> his views publicly.
>
> When Hansen posted data on the Internet in the fall suggesting that 2005
> could be the warmest year on record, NASA officials ordered Hansen to
> withdraw the information because he had not had it screened by the
> administration in advance, according to a Goddard scientist who spoke on the
> condition of anonymity. More recently, NASA officials tried to discourage a
> reporter from interviewing Hansen for this article and later insisted he
> could speak on the record only if an agency spokeswoman listened in on the
> conversation.
>
> "They're trying to control what's getting out to the public," Hansen said,
> adding that many of his colleagues are afraid to talk about the issue.
> "They're not willing to say much, because they've been pressured and they're
> afraid they'll get into trouble."
>
> But Mary L. Cleave, deputy associate administrator for NASA's Office of
> Earth Science, said the agency insists on monitoring interviews with
> scientists to ensure they are not misquoted.
>
> "People could see it as a constraint," Cleave said. "As a manager, I might
> see it as protection."
>
> John R. Christy, director of the Earth Science System Center at the
> University of Alabama in Huntsville, said it is possible increased warming
> will be offset by other factors, such as increased cloudiness that would
> reflect more sunlight. "Whatever happens, we will adapt to it," Christy
> said.
>
> Scientists who read the history of Earth's climate in ancient sediments, ice
> cores and fossils find clear signs that it has shifted abruptly in the past
> on a scale that could prove disastrous for modern society. Peter B.
> deMenocal, an associate professor at the Lamont-Doherty Earth Observatory of
> Columbia University, said that about 8,200 years ago, a very sudden cooling
> shut down the Atlantic conveyor belt. As a result, the land temperature in
> Greenland dropped more than 9 degrees Fahrenheit within a decade or two.
>
> "It's not this abstract notion that happens over millions of years,"
> deMenocal said. "The magnitude of what we're talking about greatly, greatly
> exceeds anything we've withstood in human history."
>
> These kinds of concerns have spurred some governments to make major cuts in
> the carbon dioxide emissions linked to global warming. Britain has slashed
> its emissions by 14 percent, compared with 1990 levels, and aims to reduce
> them by 60 percent by 2050. Some European countries, however, are lagging
> well behind their targets under the international Kyoto climate treaty.
>
> David Warrilow, who heads science policy on climate change for Britain's
> Department of Environment, Food and Rural Affairs, said that while the
> science remains unsettled, his government has decided to take a
> precautionary approach. He compared consuming massive amounts of fossil
> fuels to the strategy of the Titanic's crew, who were unable to avoid an
> iceberg because they were speeding across the Atlantic in hopes of breaking
> a record.
>
> "We know there are icebergs out there, but at the moment we're accelerating
> toward the tipping point," Warrilow said in an interview. "This is silly. We
> should be doing the opposite, slowing down whilst we build up our knowledge
> base."
>
> The Bush administration espouses a different approach. Marburger said that
> though everyone agrees carbon dioxide emissions should decline, the United
> States prefers to promote cleaner technology rather than impose mandatory
> greenhouse gas limits. "The U.S. is the world leader in doing something on
> climate change because of its actions on changing technology," he said.
>
> Stanford University climatologist Stephen H. Schneider, who is helping
> oversee a major international assessment of how climate change could expose
> humans and the environment to new vulnerabilities, said countries respond
> differently to the global warming issue in part because they are affected
> differently by it. The small island nation of Kiribati is made up of 33
> small atolls, none of which is more than 6.5 feet above the South Pacific,
> and it is only a matter of time before the entire country is submerged by
> the rising sea.
>
> "For Kiribati, the tipping point has already occurred," Schneider said. "As
> far as they're concerned, it's tipped, but they have no economic clout in
> the world."
>
>
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