Climate science – Jan 17

January 17, 2007

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Trees and global warming

Original: “When Being Green Raises the Heat”
Ken Caldeira, NY Times
Carbon dioxide is heating up the Earth. Ice caps are melting, ocean levels are rising, hurricanes are intensifying, tropical diseases are spreading and the threat of droughts, floods and famines looms large. Can planting a tree help stop all this from happening?

To some, it’s a no-brainer: We add carbon dioxide to the atmosphere every time we use energy from coal, oil or gas; but each tree can remove more than a ton of carbon dioxide from the atmosphere over its lifetime. Based on this logic, it might seem a good idea to go out and plant a tree to slow global heating.

And if you don’t have the time, projects have sprung up throughout the world claiming to help cool the earth, ready to accept your money and plant a tree in your name. The computer company Dell will now donate $2 from every laptop sale to planting trees in an effort to offset the carbon dioxide emissions that result from powering their computers. For a 2 percent to 4 percent surcharge on bills, Pacific Gas and Electric will offer to offset its customers’ carbon emissions by helping to preserve California’s carbon-storing forests.

While preserving and restoring forests is unquestionably good for the natural environment, new scientific studies are concluding that preservation and restoration of forests outside the tropics will do little or nothing to help slow climate change. And some projects intended to slow the heating of the planet may be accelerating it instead.

…But the notion that we can save the planet just by planting trees is a dangerous illusion. To preserve our environment, we must drastically reduce carbon dioxide emissions, and this will require a major transformation of our energy system. A primary goal for the next half-century should be to transform our energy system to one based on clean, safe and environmentally acceptable energy sources like wind, solar and perhaps nuclear. This means solving the real problems involved with storing and distributing power, providing energy for transportation, and using nuclear plants.

We cannot afford to indulge ourselves with well-intentioned activities that do little to solve the underlying problem. Instead, we must demand that our political leaders do more to revolutionize our energy system and preserve our environmental inheritance for future generations.

And then we can plant a tree.

Ken Caldeira is a scientist at the Carnegie Institution’s department of global ecology.
(16 Jan 2007)


Warming trend visible in the trees

Patrick O’Driscoll, USA TODAY
Rising temperatures are allowing Southern trees to thrive farther north and stressing trees used to colder weather, according to new national guidelines issued by planting experts.

The National Arbor Day Foundation last month updated the Agriculture Department’s “hardiness zones” map, which was last issued in 1990. The group acted after noticing that some tree species were thriving where they had not before, while others were doing poorly in what had been a suitable region on previous maps.

The shift in zones may allow people in northern areas to experiment with flowering Southern trees such as apple and cherry where they used to plant only fir, spruce and pine, says group spokesman Woodrow Nelson.
(16 Jan 2007)


Climate change linked to health problems

Mike De Souza, CanWest News Service
Canadians could wind up facing unexpected health problems because of the milder and shorter winters anticipated in the future, public health officials predict.

In an area of climate change science with many uncertainties, researchers are piecing together the increasing risks of infectious diseases, food poisoning and water contamination as Canada gets hotter.

West Nile virus and Lyme disease are two examples of illnesses that could be spreading in Canada because of global warming. However, health officials are also keeping an eye on the progression of tropical diseases such as malaria and dengue fever to ensure they won’t be able to creep north.

“Over the longer period, if a milder climate is sustained in Canada, then there is a possibility that these types of diseases could be introduced and established,” said Dr. Paul Sockett, an infectious disease expert at the Public Health Agency of Canada.
(15 Jan 2007)


The Warming of Greenland

John Collins Rudolf, NY Times
…Now, where the maps showed only ice, a band of fast-flowing seawater ran between a newly exposed shoreline and the aquamarine-blue walls of a retreating ice shelf. The water was littered with dozens of icebergs, some as large as half an acre; every hour or so, several more tons of ice fractured off the shelf with a thunderous crack and an earth-shaking rumble.

All over Greenland and the Arctic, rising temperatures are not simply melting ice; they are changing the very geography of coastlines. Nunataks – “lonely mountains” in Inuit – that were encased in the margins of Greenland’s ice sheet are being freed of their age-old bonds, exposing a new chain of islands, and a new opportunity for Arctic explorers to write their names on the landscape.

“We are already in a new era of geography,” said the Arctic explorer Will Steger. “This phenomenon – of an island all of a sudden appearing out of nowhere and the ice melting around it – is a real common phenomenon now.”
(16 Jan 2007)


Sweden’s tree line moving at fastest rate for 7,000 years

AFP
Climate change over the past two decades has caused Sweden’s tree line to move north at a faster rate than at any time in the past 7,000 years, Swedish researchers have said.

“The tree line has moved by up to 200 metres (656 feet) in some places. Trees have not grown at such high levels for around 7,000 years,” Leif Kullman, a professor at Umeaa University’s department of ecology and environmental science, told AFP Tuesday.

The tree line represents a limit in mountainous, northern and southern latitudes beyond which trees do not grow.
(16 Jan 2007)