Three Cornell researchers will discuss mitigating climate change, biochar and the challenges of wheat rust, respectively, at the 2012 American Association for Advancement of Science (AAAS) annual meeting in Vancouver, Canada, Feb. 16-20.

AAAS is an international professional association that seeks to "advance science, engineering and innovation throughout the world for the benefit of all people." It publishes the prestigious journal Science, as well as many scientific newsletters, books and reports.

Charles Greene, professor of earth and atmospheric sciences, and Johannes Lehmann, associate professor of crop and soil sciences, will both speak at the symposium "Climate Solutions: The Challenges of Getting to 350," Feb. 19. The symposium will explore the challenges society faces in getting Earth's atmosphere down from its current level of 393 parts per million (ppm) of carbon dioxide to 350 ppm. Many scientists and others believe that society can only avert dangerous climate change by stabilizing atmospheric carbon dioxide (CO2) at 350 ppm by 2100.

Greene's talk, "Geoengineering: The Inescapable Truth of Getting to 350," will center on the role of geoengineering in removing carbon from the atmosphere, and his argument that the goal of reaching 350 ppm will only be possible if humankind supplements aggressive CO2 emission reductions with CO2 removal from the atmosphere and sequestration through geoengineering.

Lehmann will discuss the challenges of reducing organic carbon and nitrous oxide emissions from the soil in his talk, "Agricultural Carbon Sequestration and Emissions Reductions: Challenges and Opportunities." Studies have shown that keeping native vegetation in place and changes in tillage practices may greatly reduce carbon organic emissions, though nitrous oxide emissions remain a challenge. At the same time, adding biochar to the soil may help reduce nitrous oxide emissions and should be further studied. Lehmann will also discuss how researchers need to broaden their view of the carbon life cycle to look at opportunities and challenges for carbon sequestration across such sectors as energy, water and recreation.

In addition, Ravi Singh, a Cornell plant breeding and genetics adjunct professor and wheat breeder at the International Maize and Wheat Improvement Center (CIMMYT) in Mexico, will discuss "The Threat of a New Wheat Stem Rust to the World's Food Supply" at the "Emerging Risks in the Global Food System" symposium Feb. 18.