Roughnecks build a drilling rig at the MEG Energy site near Fort McMurray, Alberta, Canada. In addition to large, open-pit mining operations, tar sands oil can be extracted from the ground by pumping down high-pressure steam. Michael S. Williamson/The Washington Post/Getty Images hide caption

itoggle caption Michael S. Williamson/The Washington Post/Getty Images

Golden lion tamarins are one species that are largely monogamous. Felipe Dana/AP hide caption

itoggle caption Felipe Dana/AP

Biologists normally look for the hellbender slamander, which is known by the nickname "snot otter," under rocks in streams. But now there's a gentler way: They can take water samples and look for traces of the animals' DNA. Robert J. Erwin/Science Source hide caption

itoggle caption Robert J. Erwin/Science Source

Scientists could use recordings of wildlife to monitor the movements of invasive species like the European starling. Liz Leyden/iStockphoto.com hide caption

itoggle caption Liz Leyden/iStockphoto.com

The "Giant Tabular Iceberg" floats in Antarctica's Ross Sea in December 2011. Under a proposed new international agreement, large sections of the oceans around Antarctica would become protected as a marine preserve. Camille Seaman/Barcroft Media/Landov hide caption

itoggle caption Camille Seaman/Barcroft Media/Landov

Jay Keasling (left), speaking with Rajit Sapar at the Joint BioEnergy Institute, is pioneering a technique to develop diesel fuel from yeast. Courtesy of Lawrence Berkeley National Laboratory hide caption

itoggle caption Courtesy of Lawrence Berkeley National Laboratory

Global Thermostat's pilot plant in Menlo Park, Calif., pulls carbon dioxide from the surrounding air. The next challenge is to find uses for the captured gas. Courtesy of Global Thermostat hide caption

itoggle caption Courtesy of Global Thermostat

President Obama unveils his plan on climate change Tuesday at Georgetown University in Washington, D.C. The president laid out his plan to reduce carbon pollution and to prepare the country for the impacts of climate change. Alex Wong/Getty Images hide caption

itoggle caption Alex Wong/Getty Images

The Capitol dome is seen behind the Capitol Power Plant, which provides power to buildings in the Capitol complex in Washington, D.C. Carolyn Kaster/AP hide caption

itoggle caption Carolyn Kaster/AP

Thierry Chopin from the University of New Brunswick examines a raft that holds strings of seaweed. The seaweed grows around pens of farmed salmon and soaks up some of the nutrients that would otherwise pollute the Bay of Fundy. Richard Harris/NPR hide caption

itoggle caption Richard Harris/NPR

The Houston Ship Channel is home to a wide range of heavy industry, including chemical processing plants and petrochemical refineries. Richard Harris/NPR hide caption

itoggle caption Richard Harris/NPR