She first became known in the Canadian media in the mid-1970s through her leadership as a volunteer in the grassroots movement against aerial insecticide spraying proposed for forests near her home on Cape Breton Island, Nova Scotia. The effort prevented aerial insecticide spraying from ever occurring in Nova Scotia. Years later, she and a local group of residents went to court to prevent herbicide spraying. Winning a temporary injunction in 1982 held off the spray program, but after two years, the case was eventually lost. In the course of the litigation, her family sacrificed their home and seventy acres of land in an adverse court ruling to Scott Paper. However, by the time the judge ruled the chemicals were safe, 2,4,5-T’s export from the U.S, had been banned. The forests of Nova Scotia were spared being the last areas in Canada to be sprayed with Agent Orange.

Her volunteer work also included successful campaigns to prevent approval of uranium mining in Nova Scotia, and extensive work on energy policy issues, primarily opposing nuclear energy.

For many years, she worked in her family’s business (a restaurant and gift shop on the Cabot Trail). Elizabeth is a graduate of Dalhousie Law School and was admitted to the Bar in both Nova Scotia and Ontario. She has held the position of Associate General Council for the Public Interest Advocacy Centre, representing consumer, poverty and environment groups in her work in 1985-86. She has worked extensively with indigenous peoples internationally, particularly in the Amazon, as well as with Canadian First Nations. She was the first executive director (volunteer, 1989-1992) of Cultural Survival (Canada) and worked for the Algonquin of Barriere Lake from 1991-1992.

In 1986, Elizabeth became Senior Policy Advisor to then federal Environment Minister, Tom McMillan. She was instrumental in the creation of several national parks, including South Moresby. She was involved in negotiating the Montreal Protocol to protect the ozone layer and new legislation and pollution control measures. In 1988, she resigned on principle when the Minister granted permits for the Rafferty-Alameda Dams in Saskatchewan as part of a political trade-off, with no environmental assessment. The permits were later quashed by a Federal Court decision that the permits were granted illegally.

Elizabeth has also taught courses at Queens University School of Policy Studies, as well as teaching for a year at Dalhousie University to develop the programme established in her name a the Elizabeth May Chair in Women’s Health and Environment. She holds three honourary doctorates(Mount Saint Vincent University, Mount Allison, and the University of New Brunswick.)

Elizabeth is the author of seven books, Budworm Battles (1982), Paradise Won: The Struggle to Save South Moresby (1990), At the Cutting Edge: The Crisis in Canada’s Forests (Key Porter Books, 1998, as well as a major new edition in 2004), co-authored with Maude Barlow, Frederick Street; Life and Death on Canada’s Love Canal (Harper Collins, 2000), How to Save the World in Your Spare Time (Key Porter Books, 2006), Global Warming for Dummies (co-authored with Zoe Caron, John Wiley and Sons, 2008) and most recently Losing Confidence: Power, Politics and the Crisis in Canadian Democracy, (MacLelland and Stewart, 2009). Frederick Street focused on the Sydney Tar Ponds, and the health threats to children in the community – the issue that led her to go on a seventeen-day hunger strike in May 2001 in front of Parliament Hill.

She has served on numerous boards of environmental groups and advisory bodies to universities and governments in Canada, including the Earth Charter Commission, co-chaired by Maurice Strong and Mikhail Gorbachev. Elizabeth is the recipient of many awards including the Outstanding Achievement Award from the Sierra Club in 1989, the International Conservation Award from the Friends of Nature, the United Nations Global 500 Award in 1990 and named one of the world’s leading women environmentalists by the United Nations in 2006. In 1996, she was presented with the award for Outstanding Leadership in Environmental Education by the Ontario Society for Environmental Education. She is also the recipient of the 2002 Harkin Award from the Canadian Parks and Wilderness Society (CPAWS). In 2006, Elizabeth was presented with the prestigious Couchiching award for excellence in public policy.

In June 2006, Elizabeth stepped down as Executive Director of the Sierra Club of Canada, a post she had held since 1989, to run for the leadership of the Green Party of Canada. She was successful in her bid, was elected the Green Party’s ninth leader at their national convention in August 2006.

Elizabeth was named an Officer of the Order of Canada in 2005. She is a mother and grandmother.