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4 | NewScientist | 23 March 2013 IT’S a conundrum. The world could cut greenhouse emissions by fracking for gas and replacing coal-fired power stations, but using gas to produce power could then lock us into a high-carbon future. Energy companies in the US are already extracting vast amounts of gas from shale rock using hydraulic fracture techniques, or fracking. US carbon emissions have fallen as a result, because gas-fired power stations emit less than half as much carbon dioxide per kilowatt-hour of electricity as coal-fired ones. The UK government is keen on a similar “dash for gas”, arguing that the use of domestically fracked gas could both cut energy prices and reduce reliance on imported gas. According to a new report from the Grantham Institute for Climate Change at Imperial College London, that argument Fracking dilemma is half-right. In the short term, new gas-fired power stations can help cut emissions, but only if they replace existing coal-fired power stations rather than nuclear plants or renewable energy sources. “We do need some more gas-fired power stations, but we must be careful not to build too many,” says Neil Hirst, one of the report’s authors. Beyond the 2020s, gas-fired power stations should only play a significant role if fitted with carbon capture and storage (CCS) technology, the report recommends. “It’s essential we stick to our carbon targets and press on with CCS,” Hirst says. The UK is not the only country looking closely at fracking. Shale gas is big in Australia, Poland plans to use it, and China has tonnes of the stuff. This week Saudi Arabia announced that it wants to drill test wells for shale gas. Fracking there will be difficult since the country is notoriously short of water, which is needed in vast quantities to blast rocks apart and release gas. Nevertheless Saudi Arabia is pushing ahead in the hopes of meeting domestic gas demand. A patent change INVENTORS in the US have caught up with the rest of the world – but many don’t like it. Until last week the US Patent and Trademark Office ran a first- to-invent system. Date-stamped notes proved when a gadget was invented, trouncing any rival who might have filed first. The rest of the world’s patent offices operate a first-to-file system, in which the first inventor to file a valid patent gets the rights to the idea. To simplify patenting in global markets, on 16 March the US came into line with the rest of the world, and now operates a first-to-file system. Small inventors complain that the loss of date stamping will help mega corporations invent around their ideas and patent first. But that happens already, says Peter Finnie, a patent attorney in London: “First-to-invent favoured major corporations too because they are the ones with the resources to accurately record their work and get it legally countersigned.” –To boldly glow– Plutonium power returns THE future is looking brighter for missions to the solar system’s dark corners. The radioactive isotope plutonium-238, needed to power spacecraft that cannot rely on solar energy, has been created in the US for the first time in 25 years – albeit in small quantities. Ambitious missions to the outer solar system or certain regions of Mars receive too little sunlight for solar arrays to work. Spacecraft sent to such places instead generate electricity using heat from plutonium-238. The Curiosity rover now on Mars runs on about 4 kilograms of the stuff. The US used to generate the isotope as a by-product of cold-war nuclear weapons programmes. Production stopped in 1988, and remaining stocks have been estimated at just 16.8 kilograms. Now a few grams of the isotope have been created in tests at the US Department of Energy’s Oak Ridge National Laboratory in Tennessee. Neutrons were fired at an aluminium target filled with neptunium-237, of which there is a larger stockpile. The resulting plutonium-238 was chemically separated from the target, which was then reused. The results suggest the lab could scale up to making 1.5 kilograms of plutonium-238 annually, enough to meet many, if not all, of NASA’s goals. The DOE aims to ramp up to that production level by late 2017, but it has yet to finalise its cost estimates for additional tests and upgrades to Oak Ridge and a reactor in Idaho. “Saudi Arabia wants to drill test wells for shale gas even though it is short of water needed for fracking” IF YOU find yourself in central London, consider this: beneath your feet there may well be human remains. On the edge of Charterhouse Square, engineers digging an access tunnel for the Crossrail railway project have uncovered 12 skeletons. Historical documents suggest that, in response to the Black Death sweeping Europe in the 14th century, the then-lord mayor of London ordered an emergency burial ground to be prepared at the site. Black Death burial ground found SCIENTIFICA/VISUALS UNLIMITED/CORBIS “Our evidence suggests these are burials associated with that period and therefore that these are people buried during the emergency Black Death period,” says archaeologist Jay Carver, who says a team will now look for a DNA “signature” of the plague. Skeletons discovered in a plague pit in nearby Smithfield yielded DNA markers suggesting that the Black Death was caused by the bacterium Yersinia pestis. UPFRONT
