Environmental Defense Fund or EDF (formerly known as Environmental Defense) is a United States-based nonprofit environmental advocacy group. The group is known for its work on issues including global warming, ecosystem restoration, oceans, and human health, and advocates using sound science, economics and law to find environmental solutions that work. It is nonpartisan, and its work often advocates market-based solutions to environmental problems. The group's headquarters are in New York City, with offices across the US, with scientists and policy specialists working worldwide. US regional offices include Austin, Texas; Boston; Boulder, Colorado; Los Angeles; Raleigh, North Carolina; San Francisco; and Washington, D.C. The group has a growing international presence, with offices in London, Brussels, Mumbai and Beijing. Fred Krupp has served as its president since 1984. In May 2011 Krupp was among a group of experts named by US Department of Energy Secretary Steven Chu to a subcommittee of the Energy Advisory Board that was charged with making recommendations to improve the safety and environmental performance of natural gas hydraulic fracturing from shale formations. The subcommittee issued an interim report in August and its final report in November of the same year. In 1991, The Economist called EDF "America's most economically literate green campaigners." The organization was ranked first among environmental groups in a 2007 Financial Times global study of 850 business-nonprofit partnerships. Charity Navigator, an independent charity evaluator, has given EDF a four-out-of-four stars rating overall since June 1, 2012. History The organization's founders, including Art Cooley, Robert Burnap, George Woodwell, Charles Wurster, Dennis Puleston, Victor Yannacone and Robert Smolker, discovered in the mid-1960s that the osprey and other large raptors were rapidly disappearing. Their research uncovered a link between the spraying of DDT to kill mosquitos and thinning egg shells of large birds. Their research was most likely based on the book Silent Spring by Rachel Carson about the dangers of DDT and the effects that it had on birds, published in 1962. Carson, who died in 1964, is noted as the scientist who inspired the environmental movement. The founders of EDF successfully sought a ban on DDT in Suffolk County, Long Island, New York. Next, they succeeded in banning DDT statewide, then took their efforts nationally. In looking back at passage of the Safe Drinking Water Act of 1974, top EPA officials responsible for implementing the law recall that EDF published a statistical study that supported a