11 Richard Sandbrook, Campaigner
The biologist and accountant, who died last year aged 59, had a profound influence on the green movement and the world of international development. He helped to set up Friends of the Earth UK, the Eden project and Forum for the Future. At the International Institute for Environment and Development he was instrumental in bringing together the poverty and environment agendas.
12 Amory Lovins, US energy guru
Top green thinker who launched Friends of the Earth in Britain and founded the Rocky Mountain Institute, a technology thinktank that develops blueprints for low-energy devices such as the "hypercar". He says soft technologies can cut energy use by three-quarters.
13 Vandana Shiva, Campaigner
Physicist and ecologist, founding director of the Research Foundation for Science, Technology and Ecology in India and a leader in the International Forum on Globalisation. She has had a vast impact on a range of issues from forest conservation to GM crops,from world trade policy to organic farming.
14 Ansel Adams, Wilderness photographer
Well known for his photographs of the mountain ranges, deserts, rivers and skies of the US, Adams was a passionate lover of the outdoors and an active conservationist. He commented: "My approach to photography is based on my belief in the vigour and values of the world of nature - in the aspects of grandeur and of the minutiae all about us."
15 Fritjof Capra, Austrian physicist
An Austrian doctor of theoretical physics, based in California, he combines an interest in eastern mysticism with a fascination for what makes the planet tick. His most recent book, Hidden Systems: A Science for Sustainable Living, argues the need for a natural rather than a technical toolkit to tackle the impending global crisis.
16 Aldo Leopold, US ecologist
Widely acknowledged as the founder of wildlife management as a discipline and profession, he was one of the greatest US ecologists. His writings on conservation and the value of the wild to civilisation are highly regarded. The most famous, A Sand County Almanac, inspired many to follow in his footsteps.
17 Chico Mendez, Brazilian anti-logger activist
A Brazilian rubber tapper, unionist and environmental activist who fought to stop logging in the Amazon rainforest for cattle ranching. He was murdered by ranchers opposed to his activism.
18 David Bellamy, TV botanist
A formidable campaigner for green causes, including saving a Tasmanian rainforest from flooding by a dam project. In recent years his reputation has been tarnished by public statements sceptical of climate change. Fierce hater of wind farms.
19 Joseph Bazalgette, Victorian engineer
The architect of central London's sewer system who saved the city from the cholera epidemics that had ravaged it in the early 19th century.
20 John James Audubon, US naturalist and artist
Born in 1785, his seminal work, Birds of America, a collection of 435 life-sized prints, is still a standard by which modern day bird artists are measured. While living on the family estate near Philadelphia he conducted the first known bird-banding experiment in North America by tying strings around the legs of Eastern Phoebes.
21 Sir Peter Scott, conservationist
22 Tim Smit, record producer turned gardener
23 George Monbiot, author and Guardian columnist
24 Michael Meacher, former Labour environment minister
25 Ken Livingstone, mayor of London
26 Tony Juniper, campaigner
27 John Muir, conservationist
28 Kirkpatrick Macmillan, bicycle inventor
29 Arnold Schwarzenegger, bodybuilder turned actor turned US politician
30 John Ruskin, Victorian critic
31 David Bower, Friends of the Earth founder
32 Jim Hansen, Nasa scientist
33 Thomas Malthus, economist
34 Percival Potts, public health pioneer
35 David Suzuki, ecologist and television presenter
36 Max Nicholson, ornithologist
37 Mayer Hillman, climate change expert
38 Octavia Hill, open spaces campaigner
39 Dai Qing, Chinese anti-dam campaigner
40 Paul Johnson, Greenpeace scientist
41 Paul de Jongh, Dutch author
42 Dionisio Ribeiro Filho, Brazilian environmentalist
43 Andrew Lees, campaigner
44 Mike Hands, tropical ecologist
45 Petra Kelly, German green politician
46 John Dower, national parks visionary
47 St Francis of Assisi, patron saint of animals and ecology
48 Jane Goodall, primatologist
49 Henry David Thoreau, author
50 Sunita Narain, Indian campaigner
51 Lester Brown, green policy expert
52 G K Chesterton, author
53 Swampy, roads protester
54 Sir John Banham, green industrialist
55 The people of Bougainville, eco-revolutionaries
56 Caroline Lucas, green party MEP
57 Teddy Goldsmith, Ecologist magazine founder
58 George Waterson, former RSPB director
59 Gerald Durrell, author and zoologist
60 Mark Mayer, journalist
61 Marion Shoard, writer and broadcaster
62 Nan Fairbrother, author
63 George Baker, urban conservationist
64 Dame Miriam Rothschild, scientist
65 Charlene Spretnak, US author and activist
66 Richard St Barbe Baker, forester
67 Graham Wynne, RSPB chief executive
68 Conrad Waddington, animal geneticist
69 Rudolph Bahro, author
70 Nick Hildyard, campaigner
71 Christopher Lloyd, wildlife gardener
72 Jane Jacobs, Canadian writer and activist
73 Robert Heilbronner, economist
74 Michael Braungart and Bill McDonagh, co-founders of green chemicals firm MBDC
75 Karl Henrik Robert, Swedish cancer researcher
76 Sue Clifford, campaigner
77 Colin Ward, anarchist and writer
78 Stephen Jay Gould, evolutionary scientist
79 Paul Ekins, green policy expert
80 Paul Brown, journalist
81 Mahatma Gandhi, Indian leader
82 John Stewart, roads campaigner
83 Rosamund Kidman Cox, journalist
84 Bob Flowerdew, green gardener
85 Lord John Browne, BP boss
86 Colin Tudge, author
87 Charles Darwin, naturalist
88 Tony Bradshaw, urban ecologist
89 Dalai Lama, spiritual leader
90 Herman Daly, author
91 Tom and Barbara from the Good Life, TV eco warriors
92 Siddartha Gautama Buddha, spiritual leader
93 Ted Green, trees and fungi expert
94 Alfred Wallace, naturalist and rival of 87
95 Samuel Taylor Coleridge, romantic poet
96 Margot Wallstrom, EU politician
97 Dale Vince, green energy pioneer
98 Joe Strummer, former Clash frontman turned carbon offset pioneer
99 Jamie Oliver, television chef
100 Father Christmas, carbon-free delivery