NEWS IN FOCUS SPENDING US ocean sciences SPACE Lost comet lander HEALTH Obama floats UNSUNG HEROES The snake panel calls for infrastructure poses science-mission precision-medicine milker and other behind- cuts p.538 dilemma p.536 programme p.540 the-scenes staff p.542 ANDREW BURTON/GETTY ANDREW BURTON/GETTY Regulations affecting coal-burning power plants are key to US President Barack Obama’s effort to reduce greenhouse-gas emissions. POLICY Obama acts alone on climate With little hope of support from Congress, US president unilaterally pushes regulations and international agreements in pursuit of an environmental legacy. BY JEFF TOLLEFSON most give him credit for having done what powerful greenhouse gases that are often used he has in the face of Republican opposition. as refrigerants. The president has the author- he collapse of legislation to reduce “Obama has done an amazing amount on cli- ity to make international agreements and issue US greenhouse-gas emissions was mate in his six years, and it certainly looks like regulations independent of Congress, both one of the most significant failures of he is trying to make this a legacy issue,” says houses of which came under Republican control TPresident Barack Obama’s first term in office. Kevin Kennedy, director of the US Climate with November’s elections. Halfway through his second, in the face of an Initiative at the World Resources Institute, a The long-term success of these efforts will entrenched Republican majority on Capitol non-govern­mental environmental-research depend on court rulings and the actions of Hill, Obama is now trying to build an environ­ organization in Washington DC. future administrations. The power-plant mental legacy through actions that he can take The administration is currently pushing regu- regulations in particular will be essential if the without congressional approval. lations to reduce carbon dioxide emissions from United States is to meet its commitment under “Over the past six years, we’ve done more existing US power plants, and methane from oil the US–China agreement to reduce emissions than ever to combat climate change, from the and gas production. On the international front, by at least 26% below 2005 levels in the next way we produce energy to the way we use it,” the Obama secured a deal in November with Chi- decade. Due to be finalized in mid-2015, the president said in his annual State of the Union nese President Xi Jinping that commits both standards as proposed would reduce emissions address to Congress on 20 January. “I will not let countries to reducing greenhouse-gas emis- from the electricity sector by 30% and build on this Congress endanger the health of our chil- sions over the next 10–15 years (see Nature 515, emissions reductions that have been achieved dren by turning back the clock on our efforts.” 473–474; 2014). The United States is also push- over several years through a shift away from Although environmentalists had hoped for ing domestic and inter­national measures that using coal. That shift was spurred by falling more progress when Obama came into office, would reduce emissions of hydrofluorocarbons, natural-gas prices, tightening of air-pollution 29 JANUARY 2015 | VOL 517 | NATURE | 535 © 2015 Macmillan Publishers Limited. All rights reserved NEWS IN FOCUS regulations and the growth of renewable enough for the United States to meet its putting to a vote declarations about human energy sources, especially wind power. international commitments, says Kennedy. involvement in global warming (see Nature But first, the regulations must withstand “They will have to take very serious action, http://doi.org/zpx; 2015). Fifteen Republi- inevitable industry lawsuits intended to but the tools that they have available to them cans supported an amendment to the Keystone weaken or overturn them. “The power-plant should allow them to do it.” bill stating that climate change is affected by rule is really pivotal to Obama’s legacy, and it is Republicans have vowed to challenge Obama human activity, and five voted for an amend- going to face tough legal scrutiny,” says David at every turn. They started the current session ment stating that climate change is “signifi- Victor, director of the Laboratory on Interna- with a debate on legislation to approve the con- cantly” affected by humans. tional Law and Regulation at the University of troversial Keystone Although neither amendment passed, those California, San Diego. If it succeeds, he adds, “The power- XL pipeline, which votes are a sign that Republicans are feeling “it could reverse the position of the United plant rule is would carry crude pressure and may warm to certain climate States internationally”. really pivotal to oil from the tar sands solutions in future, says Bob Inglis, a Republi- Although Obama was unable to secure Obama’s legacy, of Alberta, Canada, can former member of the House who heads climate legislation during his first term, his and it is going to to refineries on the the Energy and Enterprise Initiative, a think administration did achieve gains in the wake face tough legal US Gulf Coast. The tank that advocates for conservative environ- of the recession. It secured billions of dollars scrutiny.” House of Representa- mental solutions at George Mason University in stimulus funding for clean energy, effi- tives quickly passed in Fairfax, Virginia. Although Inglis under- ciency measures and green infrastructure, as a bill to approve the pipeline, but partisan dis­ stands why Obama has chosen to sidestep well as establishing significant new standards agreements have delayed a Senate vote. Obama Congress and address climate change with for vehicle emissions and fuel economy. That, has promised to veto the legislation. regulations, he says that the president still has combined with the economic slowdown and Although the pipeline would have a small a potential opportunity to secure his environ- the shift away from coal in the electricity sector, effect on global greenhouse-gas emissions, it mental legacy by striking a grand legislative means that US greenhouse-gas emissions have has become a symbolic issue for both sides bargain with his Republican opposition. already decreased by around 10% since 2005. of the climate debate. On 21 January, Senate “Obama is in a box,” says Inglis, “but he In theory, the administration still has both Democrats used the Keystone fight to confront could get out of that box if he were a little bit the time and the means to reduce emissions Republicans on their views about climate by bolder.” ■ SEE EDITORIAL P. 527 SOLAR SYSTEM Philae hunt hangs in the balance Rosetta mission would have to sacrifice other science to search for comet lander. BY ELIZABETH GIBNEY NEARLY WEIGHTLESS be the closest that the craft has ever been to The resulting eect of gravitational potential and 67P. But Rosetta has limited fuel. Any attempt he lost space probe Philae, which made centrifugal forces, mapped on coment to look for Philae would mean scrapping a 67P/Churyumov–Gerasimenko, is revealed to be history after it landed on a comet last greatest on the lobes and weaker in the neck region. different flyby, which would offer the chance November, is posing a dilemma for to image the comet in a shadow-free shot that Tscientists at the European Space Agency (ESA). should reveal fine details about the surface They have what is probably their last chance structure and composition. HTTP://DOI.ORG/ZP2 (2015) to change the path of Philae’s parent craft, As the comet approaches the Sun, growing Rosetta, to hunt for the lander, which went cometary surface activity in the form of jets of missing shortly after it touched down on gas and dust also makes it increasingly risky comet 67P/Churyumov–Gerasimenko. for Rosetta to approach. If Rosetta is to AL. SCIENCE ET But the shift would also mean sacrificing stick to the original flyby plan, sched- some of Rosetta’s long-planned science uled for 14 February, the craft will not observations. come as close to 67P until 2016, says The agonizing choice comes as the mis- the mission’s flight director Andrea SOURCE: H. SIERKS sion team published its first batch of papers Accomazzo, after the comet has swung from observations made after Rosetta entered around the Sun and headed back out into orbit around 67P last August — report- to space. ing a varied landscape and hinting at the comet’s origins. SURFACE SEARCH Philae has been silent since its batteries There are scientific benefits to pinpointing ran out just days after its bumpy landing on Newton metres/kilogram Philae’s location, says Wlodek Kofman, prin- 12 November. On the basis of images of its -0.27 -0.32 -0.36 -0.41 -0.45 cipal investigator on Rosetta’s CONSERT initial bounces and data from radio instru- (Comet Nucleus Sound- ments, Philae’s position has been narrowed ing Experiment by Radi- NATURE.COM down to a 20-metre by 200-metre strip. But Project scientists are debating whether to owave Transmission) For the best images efforts to find the 1-metre-wide lander in high- send Rosetta, which is still orbiting the comet, experiment, which is from Rosetta’s data resolution pictures taken by Rosetta from a dis- down to an altitude of 6 kilometres, over the designed to send radio haul, see: tance of about 20 kilometres have so far failed. patch where Philae is thought to be. It would waves between the go.nature.com/rrihsj 536 | NATURE | VOL 517 | 29 JANUARY 2015 © 2015 Macmillan Publishers Limited. All rights reserved.