Thursday, 11 October 2007

More than 16,000 Species are at Risk of Extinction


By Amy Cassara on Friday, October 5, 2007.

The United Nations' estimates that the current rate of species extinction is 1,000 times greater than it would be without human-induced habitat change, introduction of invasive species, and overexploitation. Last month, the World Conservation Union's (IUCN's) 2007 Red List, an annual report on the conservation status of the world's species, provided a more thorough accounting of this biodiversity loss. The IUCN reports that one in four mammals, one in eight birds, and one in three amphibians are in jeopardy.

More than 7,000 species experts from around the world collaborate to evaluate the status of more than 41,000 species. The Red List is unique in its global scope and the breadth of life that it examines; it includes invertebrates, plants, fungi, and algae. However, while many species groups, such as birds and mammals, are evaluated comprehensively, only a small percentage of invertebrates, plants, and fish are classified. In total, fewer than three percent of the world's 1.6 million described species have been systematically evaluated. As a result, the number of species that are actually under threat could be much higher.

This year's report includes some success stories. The Mauritian parakeet (pictured at the top of this post) was upgraded from Critically Endangered to Endangered after years of intensive recovery management. However, many other species, including the Indian crocodile, the Western gorilla, Speke's gazelle and the Egyptian vulture were assigned a more threatened status in this assessment (see http://earthtrends.wri.org/updates/node/” for more information).
For the first time this year, the Red List included species of corals. Several species endemic to the Galapagos Islands, facing the twin threats of El Nino and climate change, have been classified as endangered. Marine species are typically underrepresented in these assessments, and the IUCN is working to classify the conservation status of 15,000 additional marine species by 2010.

Sunday, 7 October 2007

Arctic ice shrinks to record low


14:21 02 October 2007
Catherine Brahic and Reuters
Arctic sea ice shrank this year to its smallest area of coverage since satellite measurements began some 30 years ago. The record low is a result of long-term climate change combined with particular weather conditions during 2007, say US scientists.
The remarkable decline made international headlines in September when European and US space agencies announced that the ice-clogged North-West Passage had completely opened for the first time, allowing vessels to sail from the Atlantic to the Pacific.
Scientists at the US National Snow and Ice Data Center (NSIDC) have revealed satellite measurements showing the full extent of summer melt during 2007. Ice is now starting to reform in the Arctic as winter approaches.
"We've got the final numbers now for this September, and it's a really dramatic record low," says Walt Meier, a member of the team studying the ice. "It didn't just break the record, it shattered the record. This year just obliterated everything else."
The average sea-ice coverage for September, when it was lowest, slipped to 4.28 million square kilometres. This is 23% less than the previous record low, set in 2005, and 39% less than the annual average between 1979 and 2000 (see image, top right).
Ice-free Arctic?
Meier says the ice coverage has followed "a steep and significant downward trend" since scientists began getting good satellite data in 1979. This long-term shrinking is attributed to greenhouse-gas emissions and the global warming they cause. He says that it would not be surprising if the Arctic became ice-free during the summer sometime in the next 25 years.
"Computer projections have consistently shown that as global temperatures rise, the sea-ice cover will begin to shrink," adds Mark Serreze, a senior research scientist at the NSIDC. "While a number of natural factors have certainly contributed to the overall decline in sea ice, the effects of greenhouse warming are now coming through loud and clear."
In addition to long-term global warming, three factors have contributed to low levels of ice in 2007. Firstly, Arctic ice was thinner than usual last winter. "Thinner ice takes less energy to melt than thicker ice, so the stage was set for low levels of sea ice this summer," explains Julienne Stroeve, another researcher at the data centre.
Secondly, temperatures were particularly high during the summer because winds brought warm air northwards. And thirdly, Arctic skies were remarkably clear. Satellite images show that skies over the Beaufort Sea were clear, or mostly clear, for 43 of 55 days between 1 June and 23 July, just as the sun was highest over the Arctic.