Can "tipping points" accelerate global warming?

[cal04]

Alister Doyle, Environment Correspondent
Rising temperatures trigger a runaway melt of Greenland's ice sheet, raising sea levels and drowning Pacific islands and cities from New York to Tokyo. In Siberia, the permafrost thaws, releasing vast frozen stores of greenhouse gases that send temperatures even higher. In the tropics, the Amazon rainforest starts to die off because of a warmer, drier climate. Such scenarios may read like the script of a Hollywood disaster movie but many scientists say there are real risks of "tipping points" -- sudden, catastrophic changes triggered by human activities blamed for warming the planet.

"Even small risks in the climate need to be considered, just as we try to avert accidents at nuclear power plants," said Stefan Rahmstorf, a professor at the Potsdam Institute for Climate Impact Research and an expert in ocean currents. "I don't think this is scaremongering. We don't really understand the system," he said of risks that the warm Gulf Stream current in the North Atlantic might shut down in one possible "tipping point" scenario. Melting ice in Greenland could send a sudden flow of cool water into the North Atlantic, disrupting the giant current that pulls warm water northwards to create the Gulf Stream. This might shut down the warm current and could also make parts of Europe and North America sharply colder, despite an overall warming of the climate.

Scenarios like this, and the uncertainty surrounding them, will provide a dramatic backdrop to a United Nations climate change meeting in Montreal, Canada, from November 28-December 9. Around 190 countries will debate how to expand a U.N.-led fight against global warming to include developing nations such as China and India and sceptic countries, led by the United States and Australia. Many environmentalists say the risk of "tipping points" makes it ever more urgent to curb climate change, already widely predicted to cause more storms and floods and even drive some species of animals and plants to extinction.

rest of the article

http://www.swissinfo.org/sen/swissinfo.html?siteSect=143&sid=6262502&cKey=1132797923000

[stepnw1f]

1. These Idiots in Power Are Gambling

our with existence.

[aquart]

2. Yes. Next question.

[scubadude]

3. I think of the environment as a balanced system.

Nature perfectly in equilibrium. All the different aspect of nature balance out one another.

Then man comes along. We add an ever increasing load of pollution to the earth while at the same time we destroy the forests and jungles which are the earths natural systems that combat pollution.

Eventually the pollution in combination with some naturally occurring events increases the load just enough for the environment to tip into catastrophic warming or cooling. The more pollution in the air, the smaller the event required to push us over the bring. Imagine a Mt. Pinatubo like eruption in combination with massive man made pollution.

The point I am trying to make is that we cannot control eruptions, but we can control pollution and the destruction of the forests thereby preserving our planets ability to cope with naturally occurring events.

Scuba

[philb]

7. Number and economic cost of natural disasters increasing rapidly

Office of US Foreign Disaster Assistance (OFDA), CRED, According to the EM-DAT, the total natural disasters reported each year has been steadily increasing in recent decades, from 78 in 1970 to 348 in 2004. 2005 had the most deaths and the most economic cost due to natural disasters of any year during this period. These disasters include droughts, tsunamis, hurricanes, typhoons and floods and have been increasing over the past 25 years. In 1980, there were only about 100 such disasters reported per year but that number has risen to over 300 a year since 2000. .

http://www.livescience.com/environment/051101_insurance_warming.html

[philb]

8. Insurance Company (Swiss Re) Warns of Global Warming's Costs

Insurance Company (Swiss Re) Warns of Global Warming's Costs

Climate Change Futures, Center for Health and the Global Environment at Harvard Medical School

http://www.livescience.com/environment/051101_insurance_warming.html

[Dead_Parrot]

4. No shit, sherlock

Since the gulf stream's slowed to about 70% of normal and the permafrost is melting, I think we can say "yes" without too much speculation. The only questions are over the timescale.

A while back I looked up the "melting" point of methane hydrate (Or rather, curve, since it depends on pressure & temperature). It's painfully close to the current temperature of the ocean for some deposits (Particulary the big one off Japan, IIRC). Hit that and we'll realy find out what a tipping point is...

[Dogmudgeon]

9. Here's a paper about methane hydrates

Steven Earle, of Malaspina U. in Canada, writes about the issue of methane release in warm periods in Instability of methane hydrates during interstadial periods. Our current interglacial period could be described as "interstadial"; Earle discusses the nomenclature, as well.

There is also a methane hydrates backgrounder which Earle wrote.

The short, not-so-sweet version of all this: undersea fields of methane hydrates (in clathrate form) are prone to collapse when the water temperature increases, as it does during interstadial periods. We are in an era of higher risk for this kind of thing, and adding such a large amount of methane gas would also accelerate global warming.

--p!

[Dead_Parrot]

10. Thanks

It's probably time I re-vistited the subject, and that looks like a good starting point... :)

[philb]

5. Yes. Tipping point for permafrost methane has already been

reached in many arctic areas such as Siberia

Siberian permafrost melting, UP, Aug 11, 2005 Sergei Kirpotin, a botanist from Tomsk State University in Russia, and Judith Marquand from Oxford University. http://www.physorg.com/news5769.html

http://www.sciencedaily.com/upi/index.php?feed=Science&article=UPI-1-20050811-15355800-bc-russia-siberiathaw.xml x....... Ice Under Fire: Arctic , http://www.worldviewofglobalwarming.org/pages/glaciers.html

[philb]

6. Scientist document Increased rate of melting of Greenland glaciers and ice

Scientist document Increased rate of melting of Greenland glaciers and ice cap, http://www.livescience.com/forcesofnature/041209_runaway_glacier.html http://news.independent.co.uk/environment/article328217.ece Dr. Gordon Hamilton, Univ. of Maine, http://www.greenpeace.org/usa/press/releases/greenland-glacier-nearly-tripl (Sermilik glacier in southern Greenland) Danish scientist Carl Boggild of GEUS, the Geological Survey of Denmark and Greenland http://news.bbc.co.uk/1/hi/world/europe/3922579.stm