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4 | NewScientist | 17 December 2011 GETTY IT DOESN’T look like we will stop putting out carbon dioxide, but we might at least be able to bury it. Carbon capture and storage (CCS) could slow climate change by locking up CO 2 . There are concerns that the gas could leak out of deep geological storage, but two of the largest pilot projects have been given a clean bill of health. As well as adding to climate change, CO 2 leaks would be toxic. In January a family living near the Weyburn-Midale CO 2 Project in Saskatchewan, Canada, found unusually high levels of CO 2 in their farm’s water. An independent report by the International Performance Assessment Centre for Geologic Storage of CO 2 has found the gas did not come from the storage reservoir. Stuart Gilfillan of the University of Edinburgh, UK, who took part in the investigation, has found Carbon burial that CO 2 leaking from deep underground has higher levels of helium than CO 2 from other sources (International Journal of Greenhouse Gas Control, DOI: 10.1016/j.ijggc.2011.08.008). That means leaks from storage facilities can be easily identified. The Canadian water samples contained normal levels of helium. In Australia, the CO2CRC project stored 65,000 tonnes of CO 2 in a depleted gas field in 2008 and 2009. So far, it reports no signs of leaks (Proceedings of the National Academy of Sciences, DOI: 10.1073/pnas.1107255108). Blood boost BONE marrow transplants may beat stem-cell injections as a way of increasing the production of blood cells when tissue is from an unrelated donor. A potential problem of either treatment – used for diseases like sickle cell anaemia – is graft- versus-host disease. This potentially fatal condition occurs when donated blood cells launch an immune attack on the host. Members of the US Blood and Marrow Transplant Clinical Trials Network monitored 273 people receiving donated stem cells and 278 recipients of bone marrow over two years. They found no difference in survival rates. But while those given stem cells produced blood cells more quickly, they also had graft-versus-host disease more often. The findings were presented at the American Society of Haematology Annual Meeting in San Diego this week. “People tend to favour stem cells because of not having to harvest bone marrow, and quicker engrafting,” says David Marks at the University of Bristol, UK. “We will need to reconsider that choice.” Geoengineer now IT’S the most urgent call for geoengineering yet: begin cooling the Arctic by 2013, or face runaway global warming. John Nissen, a former software engineer, argued for Arctic geoengineering at the American Geophysical Union meeting in San Francisco last week. He fears that soon the Arctic will be losing all its sea ice each summer and that the permafrost under the shallow waters off eastern Siberia –A helping arm makes docking easier– –Catch it while you can– SpaceX to dance with ISS IT WILL be the first flight of a new age. A US spacecraft will once again dock with the International Space Station in February, just seven months after the retirement of the space shuttle. But this is no NASA mission. Instead, the firm SpaceX, of Hawthorne, California, will fly one of its uncrewed Dragon orbital capsules on a real ISS docking and supply mission. Final approval was given last week to the idea – which has been mooted since July – of merging SpaceX’s planned ISS fly-by mission with a tricky docking manoeuvre. The decision was doubtless aided by the development of a slightly less risky way of docking. The Dragon capsule – which had its first flight last December – will take advantage of a novel technique first demonstrated by the Japanese Space Agency’s HTV1 uncrewed cargo vehicle in 2009 (see picture). Instead of approaching the pressurised hull of the station itself, the capsule will be plucked from space by the ISS’s robot arm and then slowly “plugged in” to a docking port. This avoids the risk with a direct approach of a puncture to the station’s hull. “If this mission is successful, SpaceX will start to fulfil its cargo resupply contract on the next flight. We’ve spent months working with NASA to show we are ready,” says a SpaceX spokeswoman. Scheduled for a 7 February launch from Cape Canaveral, Florida, the mission will carry hundreds of kilograms of provisions for astronauts on the ISS. “Carbon dioxide from deep storage has high levels of helium, so leaks can be easily identified” ESA/NASA UPFRONT
