Climate science - Dec 13
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2006 Warmest Year in Netherlands in 300 Years
Anna Mudeva, Reuters via Planet Ark
DE BILT, Netherlands - This year is on track to be the warmest in the Netherlands since temperatures were first measured in 1706, the Dutch meteorological institute KNMI said on Tuesday, linking the record with global warming.
The average temperature in 2006 is likely to exceed 11 degrees Celsius in the Netherlands, beating a previous record of 10.9 degrees in 2000, Rob van Dorland of the KNMI atmospheric research department told Reuters in an interview.
"So far December is warmer than normal unless we get a very cold spell in the last two weeks of the month. According to our predictions, we will have average temperatures of above 11 degrees for the year," van Dorland said.
Dutch temperature records are among the oldest in the world. Methodical thermometer-based records began on a more global basis around 1850.
(13 Dec 2006)
Arctic ice could disappear in summer by 2040: study
Global warming could melt almost all of the ice in the Arctic during the summer months by the year 2040, according to a study to be published Tuesday.
If greenhouse gases continue to build at their current rate, the study found, the Arctic's ice cover would go through periods of stability followed by abrupt retreat.
The top image, based on simulations produced by the Community Climate System Model, shows the approximate extent of Arctic sea ice in September. By about 2040 (image at bottom), the Arctic may be nearly devoid of sea ice during the late summer unless greenhouse gas emissions are significantly curtailed. (UCAR)The top image, based on simulations produced by the Community Climate System Model, shows the approximate extent of Arctic sea ice in September. By about 2040 (image at bottom), the Arctic may be nearly devoid of sea ice during the late summer unless greenhouse gas emissions are significantly curtailed. (UCAR)
One simulation projects that by 2040, only a small amount of perennial ice would remain on the north coasts of Greenland and Canada during the summer months.
This would be a more dramatic change in Arctic climate than anything we've seen so far, according to McGill University professor Bruno Tremblay, one of the study's authors. And it would also have a profound impact on global warming around the world, he said.
(11 Dec 2006)
Contributor Alan Hammaker writes:
An animation of the loss of ice can be seen at:
Greenhouse Effect Could Cause a Space Problem
Marc Kaufman, Washington Post
Far above Earth, where the atmosphere as we know it merges into empty space, lies the thermosphere -- home to space stations and satellites and very thin air. Hardly the kind of place, one might think, where human affairs would have much impact.
But just as all those cars and factories burning gasoline and coal are said to be creating a greenhouse effect, causing the lower atmosphere to warm, new research has concluded that the carbon dioxide released by humans is gradually changing the upper atmosphere, too.
The difference is that the effect is not to make it warmer, but rather to create a cooler -- and less dense -- environment. And there has already been enough of a change that those who control orbiting satellites have to take the effect into account as they do their work.
...Solomon added, however, that the cooling of the thermosphere -- which stretches from about 60 miles to nearly 400 miles above Earth's surface -- is a slow process and is "nothing to lose sleep over" on its own.
But on another level, the finding, he said, is quite important because climate researchers theorized in the late 1980s that carbon dioxide released by burning fossil fuels could have an effect on the outer atmosphere. Later scientists modeled what that effect might be, and now there is actual evidence that the thermosphere is cooling -- and that carbon dioxide is the cause. By 2017, Solomon and his colleagues predict, carbon dioxide emissions will produce a 3 percent reduction in the density of the thermosphere, with a resulting reduction in temperature.
"Carbon dioxide here will cause cooling rather than warming, but that's not what matters," he said. "What we have in common with research into the greenhouse effect is that predictions made by theoreticians were confirmed by observations. It lends credibility to the whole enterprise."
(12 Dec 2006)
Shallow fuels bring bad news
Buried deposits of greenhouse gases may be more unstable than thought.
Alexandra Witze, Nature
Geologists have discovered underwater deposits of hydrates - icy deposits of frozen methane gas - at far shallower depths under the ocean floor than expected. The finding suggests that, in a globally warmed world, the hydrates could melt suddenly and release their gas into the atmosphere, thus warming the planet even more.
Hydrates are cage-like structures in which molecules of water surround frozen molecules of gas. When dug up and brought to the surface, they release fizzy bubbles of methane into the atmosphere.
As a greenhouse gas, methane has 20 times the global warming potential of carbon dioxide. Large amounts of the world's carbon is locked up in methane hydrates, both in polar permafrost regions and buried in marine sediments worldwide. So scientists have long worried about a potentially catastrophic melting of these hydrates, triggered by an underwater landslide or warming of the ocean waters above them, that could send temperatures soaring.
Some researchers have suggested that a great global-warming episode 55 million years ago could have been caused by a catastrophic release of methane hydrates from the sea floor.
(12 Dec 2006)
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