2009 University of Texas metastudy on the cost, operational characteristics, and land-use impacts of different mass-transit technologies.
2009 study by Harvard's Belfer Center for Science and International Affairs on the cost of carbon sequestration and its long-term outlook.
2008 meta-study by the Environmental Defense Fund of the economic cost of cap-and-trade legislation to combat climate change.
2009 report by the Union of Concerned Scientists analyzing more than a decade of peer-reviewed research on genetically modified crops
In response to concerns about climate change, fossil fuels, and nuclear power, a 2009 McKinsey & Company study looks at the potential benefits of conservation.
2005 Imperial College London review of the available scholarship on the impact of red-light cameras on automotive crashes.
2009 review by the World Bank of methods available for addressing transportation-sector emissions and congestion.