Tiempo Climate Newswatch

Antarctica's largest iceberg, B-15A, has run aground. It had been expected to hit the Drygalski Ice Tongue. "This berg has wedged itself between two shallow areas," said Dean Peterson of Antarctica New Zealand. "It's kind of shimmying back and forth now … so I don't know whether it's ever going to get to the Drygalski or not." B-15A is part of a larger iceberg that broke off the Ross Ice Shelf in March 2000. It then drifted to its present location.

The 160 km-long iceberg has caused a build-up of sea ice in McMurdo Sound. The ice is threatening penguin breeding colonies, as the birds have to walk over 160 km further for food, and is restricting access to Antarctic bases. It was hoped the impact with the Drygalski Ice Tongue, referred to as "the collision of the century", would fragment the iceberg.

More information

• Los Angeles Times
• New Scientist
• Science Daily

• Animation (3Mb), ESA
• Animation, NASA
• Interview, npr

Chris Landsea, a meteorologist with the United States National Oceanic and Atmospheric Administration has resigned from the Intergovernmental Panel on Climate Change (IPCC) in protest against statements allegedly made by an IPCC lead author. Landsea claims that Kevin Trenberth, from the National Center for Atmospheric Research gave a personal opinion at a Harvard press conference linking present-day changes in hurricane activity to global warming, rather than reflecting the IPCC consensus as Landsea considers a lead author should.

Trenberth denies he linked global warming to last year's hurricane strikes on Florida nor did he claim any link with hurricane frequency. "What we are suggesting is that when a disturbance does form a hurricane it's apt to be more intense and there's heavier rainfalls." In withdrawing, Landsea said that he had "come to view the part of the IPCC to which my expertise is relevant as having become politicized."

More information

• ENN

A new report claims that the price of removing carbon from the atmosphere using forests, sequestration, could be close to the cost of improving energy efficiency or fuel switching. The study, from the Pew Centre, calculates that sequestration on forest land could take 300 million tons of carbon out of the air at a cost of between US$25 and US$75 a ton. This is similar to the cost of other measures intended to reduce emissions from buildings, automobiles and appliances.

"When and if a mandatory domestic greenhouse gas reduction programme is established in the United States, a carefully designed carbon sequestration programme really ought to be included in a cost-effective portfolio," said report co-author Robert Stavins, a Harvard University economist. It would take, though, reforestation or afforestation over an area the size of Texas to remove one-fifth of annual US emissions. There are also unanswered economic, social and political issues.

More information

• ENN
• Press release, Pew Center
• Download report, Pew Center