NEWS OF TH E WEEK
AFFIRMING IMPACTS OF CLIMATE CHANGE
Droughts, such as the one in China’s Guizhou province, and other climate events show how vulnerable some ecosystems are to global warming, an IPCC report says.
tinued growth in greenhouse gas emissions, risks will be challenging to manage,” says Christopher Field, who cochaired the IPCC working group that prepared the report. “Even serious, sustained investments in adaptation will face limits,” says Field, founding director of the Carnegie Institution’s Department of Global Ecology at Stanford University. Sen. Barbara Boxer (D-Calif.), who chairs the Senate Environment & Public Works Committee, says the IPCC report “adds a tremendous sense of urgency for Congress to wake up and do everything in its power to reduce dangerous carbon pollution.” The report also touches briefly on geoengineering—which would involve large-scale efforts to block incoming solar radiation or to strip CO2 from the atmosphere—but does not endorse it. Costs, effectiveness, and side effects of geoengineering techniques are poorly understood, the document says. The report is the second in a series of three that IPCC is releasing as part of its fifth in-depth assessment of climate change since 1990. The first of these, examining the science of climate change, was released in September 2013. The third IPCC report, on mitigating climate change, is due in mid-April. The reports are expected to influence international negotiations on a new climate-change treaty, which are due to conclude at the end of 2015.—CHERYL HOGUE
NEWSCOM
IPCC: Report probes effects, adaptation, and vulnerabilities related to global warming
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ROUND THE GLOBE, human-caused climate
change has affected farming, water supplies, and ecosystems on land and in water, says a new United Nations report. Compiled by the Intergovernmental Panel on Climate Change (IPCC), the report says melting of permafrost and many glaciers as well as a shift in many species’ geographic ranges is a result of global warming. Climate change thus far has caused more harm than good to crops, it concludes. And the current rate of ocean acidification, caused by uptake of atmospheric carbon dioxide, is unprecedented in the past 65 million years. The report, released last week, examines the impacts of global warming and societies’ vulnerability to those effects. The document also assesses how societies are adapting to climate change. “With high levels of warming that result from con-
CYANOFORMATE STRUCTURE SOLVED UNSTABLE COMPLEX: Elusive ion could help develop carbon dioxide capture technology
formate (NCCO2−) has been tough to catch. But scientists have now trapped the fleeting anion. The achievement could guide the design Tetraphenylphosphonium (left) of agents that capture the greenhouse gas enabled the capture of the elusive carbon dioxide. cyanoformate anion (right). Jason A. C. Clyburne of Saint Mary’s University, in Halifax, Nova Scotia, and coworkers captured cyanoformate as a tetraphenylphosphonium salt and obtained its crystal structure (Science 2014, DOI: 10.1126/ science.1250808). The structure shows that the anion is a Lewis acid base adduct in which the carbon from cyanide donates a pair of electrons to the carbon in CO2. “It’s a donor-acceptor complex CEN.ACS.ORG
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K ATHERIN E ROBERTSON
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OR SUCH A SEEMINGLY simple ion, cyano-
between a base and an acid,” Clyburne says. “But it forms only a very weak carbon-carbon bond,” adds Heikki M. Tuononen of the University of Jyväskylä, in Finland, whose research group examined the electronic structure of the anion with theoretical methods. Cyanoformate “is as reactive and as unstable and as sensitive a molecule as I’ve ever isolated,” Clyburne says. “Cyanide is a stable entity, and CO2 is a stable entity. Yet, under the right conditions we can pair them, isolate the complex, and study its decay.” Clyburne and coworkers also stabilized another salt of the anion in an ionic liquid. By using different solvents, they were able to study the anion’s degradation as a function of the dielectric constant of the solution. “The chemistry of CO2 is significantly different in lowdielectric media,” Clyburne says. In the anion, “cyanide is only barely able to hold onto the CO2,” says Philip G. Jessop, a professor at Queen’s University, in Kingston, Ontario, and technical director of GreenCentre Canada. That weak binding means the work could inspire new strategies for capturing CO2 from power plant emissions. “If or when society decides to do something about global warming, work like that of Clyburne will be crucial to the design of the most energy-efficient CO2 scrubbing agent,” Jessop says. “In that process, one needs something to bind CO2 but not bind it too strongly, so that release of the CO2 is easy when the binding agent needs to be regenerated.”—CELIA ARNAUD
APRIL 7, 2014
