Apocalypse NowHow Mankind Is Sleepwalking to the End of the Earth
by Maria Gilardinhttp://www.dissidentvoice.org/Sept05/Gilardin0921.htmwww.dissidentvoice.org
This headline appeared in the London Independent in early February of 2005, following a conference at the Hadley Centre in Exeter, England, where 200 of the world’s leading scientists issued the most urgent warning to date: that dangerous climate change is taking place today, and not the day after tomorrow.
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The award winning environmental writer Geoffrey Lean wrote: “Future historians, looking back from a much hotter and less hospitable world . . . will puzzle over how a whole generation could have sleepwalked into disaster -- destroying the climate that has allowed human civilization to flourish over the past 11,000 years.”
The overwhelming majority of scientists and international climate monitoring bodies now agree that climate change is taking place, that humans are responsible, and that time is running out. In fact, we could reach “the point of no return” in a decade, reported Lean.
Melting glaciers all across the world include: the Broggi in the Peruvian Andes, Glacier Ururashraju in the Cordillera Blanca of Peru, the Pasterze in Austria, Portage Glacier near Anchorage, Alaska, Mount Hood in Oregon, Mount Kilimanjaro in northeastern Tanzania, the Grinnell Glacier in Glacier National Park, and the Rhone Glacier in Switzerland.
The earth is getting warmer. While average warming is just under 1 degree Celsius worldwide, the Polar Regions show warming of 2 to 3 degrees Celsius, due to feedback effects. With the melt of white snow, that previously reflected some of the heat back into the atmosphere (albedo effect), newly exposed darker surfaces absorb heat, and accelerate melting of more ice and snow.
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First Signs of a Gulf Stream CollapseThe opening presentations at the Exeter, UK conference gave the most comprehensive assessment of so-called “wild cards”, climate change events that risk feedback loops no longer responsive to human intervention. The run-away events, or ecological landslides include accelerated melting of the enormous ice sheets of Antarctica and Greenland, as well as the decline and possible reversal of the Gulf Stream that conveys heat from the tropics to Europe.
In the Hollywood movie “The Day After Tomorrow,” the Gulf Stream stops flowing in a matter of days, creating an instant ice age on the Atlantic coast and Western Europe. Scientists at Exeter said it would take at least ten years for such an event to unfold and a few hundred years to set up the conditions. But they warned that the Thermohaline Circulation, as they call the Gulf Stream, has stopped flowing before -- and that we have already a greater than 50% likelihood of a shutdown if we do not enact strict climate policies.
The amount of heat transported North by the Gulf Stream, which keeps Western Europe 5 to 10 degrees Celsius warmer than it would normally be at its latitude, equals one million billion watts -- sufficient to satisfy the energy needs of 100 Earths. Even a partial failure of the Gulf Stream would have huge consequences.
The Gulf Stream picks up heat from the equatorial sun. Driven by warmth, the stream flows northeast towards Europe and the Greenland ice sheets, where the water cools and sinks. The cooler and saltier the water, the stronger the sinking motion. Dense cool and salty water from the Gulf Stream then flows back to the tropics at a deeper ocean level.
As the Polar Regions and the oceans are warming, melt-water from ice sheets and glaciers is changing the salinity of the ocean. A combination of the rising ocean surface temperature, and the decreasing salinity, already visibly changes the movement of sea currents that depend on differences in warmth and coolness, and the weight that higher salinity adds to the water as the driving force.
Large-scale salinity changes in the Arctic and sub-Arctic Seas were reported in June 2005, in the journal Science. Ruth Curry from the Woods Hole Oceanographic Institution on Cape Cod, in Massachusetts, analyzed temperature, salinity, and density data, collected in the North Atlantic Ocean over the last 55 years. Curry warned that excessive amounts of freshwater dumped into the North Atlantic could affect the flow of the Gulf Stream.
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