U.S. forests and soils store some 90 billion metric tons of carbon, or 50 years worth of present U.S. emissions from fossil fuels, according to a new study from the U.S. Geological Survey. As negotiators here at the United Nations' climate summit continue to struggle to draft a global agreement to cut greenhouse gas emissions—including efforts to reduce deforestation and protect natural sinks—the U.S. Department of Interior is transforming the business of public lands and waters to help combat climate change.