Sunday, January 14, 2007

Microbe experiment suggests we could all be Martians | Special reports | Guardian Unlimited

Ian Sample, science correspondent
Saturday January 13, 2007
The Guardian

Life on Earth may have announced its arrival billions of years ago with a whistle and a thump, according to planetary scientists.

Experiments by an international team of researchers back a controversial theory that life flourished on Earth after primitive organisms arrived aboard a meteorite, itself gouged from Mars by a giant impact.

The theory supposes that life was able to gain a tentative foothold on the red planet as it cooled down and became more hospitable several billion years ago. At the time, the planet's surface was regularly bombarded with rocky detritus from the asteroid belt, knocking clumps of rock and the microbes living on them into space, where the gravity of the sun brought them hurtling towards Earth.

Article continues

Friday, January 12, 2007

Cold-loving algae discovered in Arctic

A new life form of tiny, cold-loving micro-organisms involved in photosynthesis have been discovered in the Arctic Ocean, according to an international team of scientists, including a Canadian researcher.

The tiny plant organism, called a picobiliphyte, is distinct from anything else in the ocean, according to Université Laval biologist and professor Connie Lovejoy.

Monday, January 08, 2007

Jurisdynamics: One Million More Reasons Not to Fly?

Cumulative Effects
By J.B. Ruhl

Gazing out the window of an exit row seat on a plane trip back from a conference last week, I was reminded of a news item I saw in a recent issue of Scientific American ("Hot Trails," Sept. 2006, page 28). It turns out that in the days following 9/11, when jet traffic was basically zero, average daytime temperatures for the nation rose slightly and nighttime temperatures dropped more substantially. This finding supported a long held hypothesis that jet contrails reduce the temperature range by cooling the temperature during the day and heating it at night. Contrails are condensation trails that act essentially as thin cloud barriers that both reflect sunlight and block the earth's heat from rising. During the day the former effect is dominant, and during the night the latter effect is exclusive (because, obviously, there is no sunlight to reflect).

Armed with this proof, the ingenious legal mind might suggest ways of shifting flights from night to day as a way of countering global climate warming. We could auction off limited night slots, allow trading of night flight rights, etc. The net effect should be to take advantage of the daytime cooling effect of contrails and reduce their nightime heating effect.

Not so fast. The contrail effect is a classic "cumulative effects" phenomenon--the aggregate effects of many small individual similar events. It is an unfortunate term because it suggests that aggregation effects are linear. But is one contrail's effect of "x" on temperature simply aggregated, so that 100 contrails in a region equal an effect of 1oox? Most likely not. We already know that time matters. Space probably matters too. And the aggregation of effect in any time-space context may exhibit nonlinear properties, such that 100 contrails in a region over a defined time have an effect of 50x or 150x. Perhaps, for example, the number of daytime contrails is just below the threshold at which any more will tip the dominance over to the heat barrier effect. And maybe the number of nighttime contrails is well above the nonlinear threshold at which fewer contrails make a difference. Then our ingenious market-based solution would lead to exactly the wrong result. After all, all we really know is the effects of contrail numbers lumped around two points--zero contrails and status quo. It is amazing we know even that--it was the result of a one-time (we hope) disaster; it is not likely the FAA ever would have allowed anyone to test the hypothesis by banning all flights for a week. We clearly do not know what happens, therefore, between zero and status quo or beyond.

Arctic melt soaks up carbon dioxide - climate-change - 06 January 2007 - New Scientist Environment

THE clouds of global warming don't exactly boast a silver lining, but there is a little bonus. Melting sea ice in the Arctic is enabling ocean waters to soak up more carbon dioxide from the atmosphere. Ice retreat over the last 30 years has tripled the amount of CO2 the Arctic Ocean can absorb.

Nick Bates of the Bermuda Institute of Ocean Sciences and colleagues calculated CO2 uptake in the Arctic Ocean from measurements taken from the Chuckchi Sea and Canada basin in 2002 and 2004. They found that CO2 uptake from the atmosphere increased dramatically during the summer months, when sea ice was at a minimum (Geophysical Research Letters, DOI: 10.1029/2006GL027028).

"Sea ice acts as a barrier to gas exchange," says Bates. Overall they calculated that the entire Arctic Ocean is currently able to absorb up to 66 million tonnes of CO2 per year. Future ice-melt may increase absorption by a further 20 million tonnes per decade. However, this won't be enough to offset global warming: currently worldwide emissions amount to over 30 billion tonnes per year.

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