Climate change is a complex, crosscutting issue that poses risks to many existing environmental and economic systems, including agriculture, infrastructure, ecosystems, and human health. A 2009 assessment by the United States Global Change Research Program found that climate-related changes, such as rising temperature and sea level, will combine with pollution, population growth, urbanisation, and other social, economic and environmental stresses to create larger impacts than from any of these factors alone. Funding for climate change activities is spread across the federal government. This...