Abbey, Edward (1927-89): US writer. His novel The Monkey Wrench Gang (1975), about an ecologically-minded group sabotaging construction equipment being used to destroy wilderness, was an inspiration for radical environmental groups such as Earth First!.

Angel, Jeff: longstanding Australian environmentalist and director of the Total Environment Centre in Sydney.

Arrhenius, Svante (1859-1927): Swedish physicist and chemist who first suggested in 1896 that carbon dioxide from human industry was creating a greenhouse effect and warming the atmosphere.

Attenborough, David: iconic British TV presenter of nature programmes since 1950s.

Balfour, Eve (1899-1990): English farmer and educator; her book, the Living Soil (1943) laid out the principles of organic farming and is regarded as a catalyst for the organic movement.

Benyus, Janine: US natural science writer who developed the idea of biomimicry.

Bookchin, Murray (1921-2006): US libertarian socialist. Wrote The Ecology of Freedom (1982), arguing that environmental problems originated in social problems and capitalism. Influenced direct-action groups such as Reclaim the Streets.

Bradley, Joan and Eileen: invented the “Bradley method” of bush regeneration by pulling out exotic weeds by hand in the late-60s/early-70s.

Brower, David (1912-2000): founded Friends of the Earth in 1969.

Brown, Bob: founding member and leader of Australia’s Greens party, the leading figure in Australian green politics since the 1980s.

Brown, Lester: US environmentalist. founder of the Worldwatch Institute and founder and president of the Earth Policy Institute.

Butler, Dorothy (1911-): known as the “barefoot mountaineer”,  Sydney bushwalker, mountaineer and environmentalist involved in campaigns to establish national parks.

Byles, Marie (1900-1979): Sydney bushwalker and conservationist.

Caldicott, Helen: Australian anti-nuclear activist.

Carson, Rachel (1907-64): US author of Silent Spring (1962) about the environmental problems caused by artificial pesticides. The book is regarded as a key influence in the developing environmental movement and led to the banning of DDT.

Cohen, Ian: peace activist and first Greens NSW Senator (elected in 1995).

Crutzen, Paul: Nobel Prize-winning physicist, largely responsible for identifying the damage CFCs aerosols were doing the the ozone layer.

Cundall, Peter: As well as long-time presenter of ABC's Gardening Australia, Cundall has also been important figure in the growth of the organic movement in Australia. He was the Chairman of the Tasmanian Wilderness Society during the battle to stop the building of the Franklin Dam.

Daly, Herman: US ecological economist, best known for his book Steady State Economics (1991), advocating a stable, no-growth economy as a sustainable alternative model to the growth economy.

d'Eaubonne, Françoise: French eco-feminist who coined that term in her 1974 book Feminism or Death.

Deans, Ester: Australian gardening writer and conservationist who introduced no-dig gardening to Australia in the 1970s.

Diesendorf, Mark: Australian academic specialising in renewable energy; author of Greenhouse Solutions with Sustainable Energy (2007).

Dombrovskis, Peter (1945-1996): landscape photographer; his iconic image of the Franklin River played a key role in the campaign to save the river.

Dunphy, Myles (1891-1985): bushwalker and influential Australian environmental activist.

Dunphy, Milo (1929-1996): director of Total Environment Centre, campaigned for creation of Greater Blue mountains National Park in 1970s. Co-director with Bob Brown of United Tasmania Group.

Ehrlich, Paul: US zoologist and author of The Population Bomb (1968), which predicted mass starvation from overpopulation in the 1970s.

Farley, Rick: leader of the National Farmers Federation in the 1990s; developed the Landcare scheme with the ACF.

Foreman, David: founded radical environmental direct action group Earth First! in the late-1970s.

Fourier, Joseph (1768-1830): first person to identify the greenhouse effect of gases in the atmosphere in 1824.

Flannery, Tim: Australian scientist and author of The Future Eaters, about human impacts on their environment, and The Weather Makers, about climate change. Probably Australia's best-known environmentalist.

Fukuoka, Masanobu (1913-2008): Japanese pioneer of natural gardening in the 1930s, the forerunner of permaculture and no-dig gardening.

Fuller, Buckminster (1895-1983): US thinker and futurist; coined the term "Spaceship Earth"; invented the geodesic-dome.

Garnaut, Ross: prominent Australian economist and author of the Australian Government's climate change review.

Garrett, Peter: former Midnight Oil singer who become president of the ACF and is currently the Federal Minister of the Environment.

Goldsmith, Edward: UK environmentalist, founder of the Ecology Party (which became the UK Green Party) and the magazine The Ecologist. Known for anti-industrialism views and support for tribal societies and organic farming. Author of Blueprint for Survival (1972).

Gore, Al: former US President under Bill Clinton, his film An Inconvenient Truth (2007) helped spread awareness of climate change into the mainstream.

Hamilton, Clive: left-of-centre economist; heads The Australian Institute thinktank; author of Affluenza (2005) and Scorcher (2007).

Hansen, James: director NASA Goddard Space Studies Centre: influential US scientists who was one of the first to identify the speed and scale of global warming.

Hardin, Garrett (1915-2003): US ecologist who coined the phrase "The Tragedy of the Commons" in an influential paper of that name (1968).

Harris, Thistle (1902-1990): biologist whose book Wildflowers of Australia (1938) popularized the use of native Australian plants in gardens.

Henry, Don: Executive Director of the Australian Conservation Foundation (and former Australian Director of the World Wide Fund for Nature).

Holmgren, David: co-founders of the permaculture movement.

Howard, Alex (1873-1947): British botanist regarded as the father of modern organic farming with books An Agricultural Testament (1940) and The Soil and Health, A Study of Organic Agriculture (1947), based on his experience of Indian farming methods.

Jones, Van: US writer and a leading proponent of the "green collar economy", the idea that green innovation will create jobs.

Karoly, David: Professor at School of Earth Sciences, Melbourne University, and one of the lead authors of the 2007 IPCC climate change report.

Kaye, Henrietta: founder of anti-whaling Project Jonah in 1976.

Kelly, Petra (1947-92): co-founder of the German Green Party in 1979, she was probably the world's most prominent Green politician during the 1980s.

Keto, Aila: helped found the Rainforest Conservation Society in 1982; key figure in the campaign to save the Daintree.

Kiernan, Ian: founder of CleanUp Australia.

Kovel, Joel: US academic and influential eco-socialist.

Lowe, Ian: scientist and environmentalist; President of Australian Conservation Foundation.

Lovelock, James: UK author of the Gaia Hypothesis, a key modern formulation of the idea that the earth’s biosphere functions much like a single living organism. Also one of the earliest scientists to identify climate change

Lovins, Amory: Chairman and Chief Scientist of the Rocky Mountain Institute; one of the authors of Natural Capitalism, an influential book which proposes that the next industrial revolution will be based upon companies adopting sustainability principles.

McDonagh, William: US sustainable architect and co-author of Cradle to Cradle (2002), urging that human design emulates nature in constantly recycling all waste as the basis for new products.

McKibben, Bill: US writer: author of The End of Nature, and founder of 350.org, a grassroots climate change movement.

Marsh, George Perkins (1801-1882): often regarded as America's first environmentalist. Played a role in the creation of the Adirondack Park. His book Man and Nature argued deforestation could lead to desertification.

Maathai, Wangari: Kenyan environmentalist who founded the Green Belt Movement, which hs planted over 40 million trees across Kenya to prevent soil erosion. The first African woman to receive the Nobel Peace Prize.

Meyer, Aubrey: founder of the UK-based Global Commons Institute, which advocates the principle of Contraction and Convergence

Milne, Christine: Green senator for Tasmania, deputy leader of the Australian Greens.

Monbiot, George: UK academic, journalist and activist and a leading figure in the UK environmental movement.

Mollison, Bill: Tasmanian academic and writer; co-founder of the permaculture movement.

Mosley, Geoff: bushwalking and conservation activist, campaigned for creation of national parks; ACF director 1973-86.

Muir, John (1838-1914): US naturalist, writer and founder of the Sierra Club in 1892, one of the main environmental organisations in the US. A key influence on the development of the environmental movement.

Munday, Jack: union leader who instigated Sydney “green bans” movement in the 1970s.

Nader, Ralph: US political activist and Green Party candidate in the 1996 and 2000 Presidential elections. (He ran as an independent in 2004 and 2008).

Neidjie, Bill (1912?-2002): a central figure in getting Kakadu returned to indigenous ownership and establishing it as a national park.

Ness, Arne (1912-2009): Norwegian philosopher who formulated the theory of Deep Ecology.

Odum, Howard T. (1924-2002): influential US ecologist who developed the concept of ecosystems and ecological economics.

Pearse, Guy: climate change policy analyst and former Australian Liberal party staffer who revealed the power of Australia's fossil fuel lobby in his 2007 book High & Dry.

Podolinsky, Alex: director of the Biodynamic Research Institute near Melbourne in the 1950s, a key figure in establishing biodynamic farming in Australia.

Sachs, Jeffrey: US economist and director of Columbia University's Earth Institute. Regarded as one of the world's leading environmental economists, he has been criticised for advocating neo-liberal, globalisation development policies.

Sandor, Richard: US economist credited with inventing the concept of carbon trading (and also the financial "future" trade)

Schumacher, EF (1911-77): author of the influential book, Small is Beautiful (1973), advocating a move to more decentralised technology and social organisation.

Schwarzenegger Arnold: Hollywood movie star who has become one of the world's most environmentally progressive political leaders as the Republican Governor of California.

Serventy, Vincent: writer and documentary-maker and president of Wildlife Preservation Society of Australia in the 1970s. Made the popular nature TV series Shell’s Australia in the late-1960s.

Seymour, John (1914-2004): UK author of The Complete Book of Self-Sufficiency (1976), which helped popularise the idea of downsizing and self-sufficient living.

Shiva, Vandana: Indian physicist, environmental activist and author. She is a leading anti-GM food campaigner and figure in the "anti-globalisation" or global solidarity movement.

Spretnak, Charlene: co-founder of US Green Party; eco-feminist.

Stead, David (18??-1957): marine biologist and campaigner; founded the Wildlife Preservation Society of Australia, the country’s first conservation organization, in 1909. A key figure in the early Australian environmental movement.

Steiner, Rudolph (1861-1925): Austrian philosopher who created, among other things, biodynamic farming.

Stern, Lord Nicholas: UK economist who chaired the UK Government's Stern Report into climate change.

Suzuki, David: influential Canadian environmental writer and broadcaster

Pachauri, Rajendra: Indian economist and chair of the Intergovernmental Panel on Climate Change (IPCC)

Thoreau, Henry David (1817-1862): US writer and pioneering environmentalist. His book Walden, a meditation on nature and self-sufficiency written about his stay in a woodland classic, is considered one of the great environmental classics and early critiques of Western materialistic society.

Truchanas, Olegas (1923-1972): influential nature photographer and Tasmanian environmentalist; played a key role in the campaign to save Lake Pedder and the creation of the United Tasmania Group, which became The Greens.

Watson, Paul: former Greenpeace director and founder of Sea Shepherd, a radical environmental group which uses direct action to hinder and publicise Japanese whaling.

Wright, Judith: poet and environmentalist, played a role in campaign to prevent development of Fraser Island. Co-founder of Wildlife Preservation Society of Queensland in 1962.

Zhengrong Shi: Chinese solar power entrepeneur who founded Suntech Power, the world's largest manufacturer of solar panels. Studied at the UNSW in Sydney.