2010 University of California, Los Angeles, study published in Transport Policy on the relationship between bicycle use and riders' immigrant status.
2009 study published in Environmental Science and Technology on the costs and potential benefits of substituting biomass for coal to generate energy.
2010 study by the University of Maryland and other institutions on the long-term environmental impacts of mountaintop coal mining.
2010 report by the National Resource Council on the cost of the production and use of various forms of energy in the United States.
2009 study by Harvard's Belfer Center for Science and International Affairs on the cost of carbon sequestration and its long-term outlook.
2009 review by the World Bank of methods available for addressing transportation-sector emissions and congestion.