The NS panel
Lord Browne is president of the Royal Academy of Engineering and a former chief executive of BP. He is a cross-bench life peer.
Caroline Lucas is leader of the Green Party and a Member of the European Parliament for the South East England region.
Mark Lynas is an NS columnist, activist and author of Six Degrees, winner of the Royal Society Science Books Prize.
John Sauven is executive director of Greenpeace UK.
Bibi van der Zee is an NS columnist and author of Rebel, Rebel: The Protestor's Handbook.
For a few hours one morning earlier this month, wind energy provided more than half of Spain's total electricity needs. Spain's network of wind farms was generating 11.5 gigawatts, equivalent to ten medium-sized power stations. Why is Britain not latching on to this cutting-edge clean technology with the same vim? After all, we have a much greater wind resource to exploit than Spain. A principal reason is probably the unquestioning acceptance by many of the myth that wind power is too variable in its output and requires a large amount of energy back-up - provided by fossil fuels or nuclear power - to stop the lights going out.
So when National Grid - which should know about such matters - published a comprehensive report in June exposing this myth, it was a huge boost for the wind industry. The 82-page report thoroughly debunked the suggestion that large rises in back-up power will be needed as Britain increases the amount of energy generated by wind.
Later in the year, National Grid weighed in to make the same point again. When the respected renewable energy expert and consultant David Milborrow wrote a report showing that Britain's energy system is already capable of taking a large amount of wind power, National Grid backed his work.
The Gaia guy
As one of the people who saw climate change coming, James Lovelock takes a positive view of our impending doom. He evolved the theory of Gaia - that our planet is "a single living entity" - 40 years ago, and showed the delicacy with which our precious atmosphere is balanced.
He wrote in 1979 that "if we stopped burning [fossil fuels] tomorrow it might take 1,000 years for atmospheric carbon dioxide to revert to its normal level", but he now believes that catastrophic global warming is inevitable and that probably 80 per cent of the human race will be wiped out by the end of the century. Never mind, he says, it will be like the Second World War: once it was under way "everyone got excited, they loved the things they could do, it was one long holiday . . . so when I think of the impending crisis now, I think in those terms. A sense of purpose - that's what people want."
Bibi van der Zee
When Vestas closed its factory on the Isle of Wight in the summer, there was one company left producing wind turbines in the UK. By then Skykon had already bought another Vestas plant on the Mull of Kintyre, saving some 100 jobs and promising to create around 200 more. The plant manufactures towers for wind turbines and is an important symbol of the green new deal proposed by environmental campaigners and green politicians. Growth in a period of recession: proof that environmental investment makes sense.
The environmentalist and politician Marina Silva was named "Champion of the Earth" by the United Nations Environment Programme for her groundbreaking fight against defores-tation in Brazil. A native Amazonian, she unionised communities and led protests against deforestation and displacement. She became a senator and built support for environmental protection of reserves, and implemented policy that brought social justice and sustainable development to the Amazon region. When she resigned from government last year, a top Greenpeace official said "it's time to start praying". These prayers have been answered: Silva is the Brazilian Green Party's presidential candidate in the next election.
Some people view the possibility of climate change with apathy or despair; others, such as Pachauri, approach it with boundless enthusiasm and hope. The chair of the Intergovernmental Panel on Climate Change (IPCC) since 2002, Pachauri is one of the world's most important scientists. The IPCC's Fourth Assessment Report, released in 2007, is the starting point for anyone interested in why tackling climate change will be the most pressing political issue of the 21st century.
Pachauri and the IPCC had to work hard to convince sceptics of their arguments. Climate change science is inherently probabilistic and critics exploit that uncertainty to promote alternative agendas. But as a businessman and an engineer, I have always found Pachuari's approach to problem-solving very refreshing. His motto appears to be: "If you can't find a solution, you're simply looking in the wrong place." Through tireless and dedicated science, the IPCC has created a stable consensus on the need for action on climate change. The message has been projected beyond the scientific community and is now adopted by businessmen, policymakers, religious leaders and civil groups. This is a precious first step.
Since "losing" the 2000 US presidential election, Al Gore has become one of the world's leading environmental campaigners. His documentary, An Inconvenient Truth, helped bring climate change into the political mainstream. Gore won the Nobel Peace Prize in 2007, sharing it with the Intergovernmental Panel on Climate Change. The Nobel award panel noted Gore's efforts to "disseminate greater knowledge about man-made climate change and to lay the foundations for the measures that are needed to counteract such change". His work did not end there. Gore is the chair of the Alliance for Climate Protection and has published Our Choice, a new book on climate change.
The writer Bill McKibben is an unlikely hero. His dedication to the cause often comes across as humourless and worthy. But underlying everything he does is a consistent commitment to radical environmentalism, a philosophy he has helped move from the margins to the mainstream in both science and politics. McKibben wrote the first popular study of global warming: his The End of Nature (1989) is to the climate change movement what Rachel Carson's Silent Spring (1962) was to the early environmental movement.
Over the past year, McKibben has completed an unusual transformation from writer to full-time campaigner, founding and directing 350.org, a grassroots coalition focusing on reducing atmospheric carbon concentrations to safer levels. The number 350 refers to the level (measured in parts per million) that scientists have identified as the safe upper limit of CO2 in the atmosphere. The bad news is that current CO2 levels are at around 387 parts per million, so we're already in the red zone. The genius of 350.org is that it marks a refusal to compromise. The positions on climate change taken by most countries suggest an acceptance that it is too late to save the coral reefs, to stop Greenland melting down, or to protect food security in the face of increasing floods and droughts - 350.org, thanks to the wisdom of McKibben, does not.
Power of ten
The activist and documentary film-maker Franny Armstrong released The Age of Stupid to great critical acclaim earlier this year. Featuring a man in the year 2055 looking at archive footage from an era when "we could have saved ourselves", it was hailed internationally as a wake-up call. Armstrong's latest campaign, 10:10, aims to cut 10 per cent of the UK's emissions during the year 2010 by inspiring individual action and a cultural shift towards sustainability. The entire Labour cabinet has signed up, along with celebrities such as Colin Firth and Samantha Morton and organisations including Tottenham Hotspur and Microsoft.
It can be "very lonely work" being an environmentalist in China, says Wen Bo. Nonetheless, he has persevered in the face of an uninterested public and a government that suppresses criticism. After setting up Greenpeace's Beijing office in 2000, he became head of China operations for the California-based Pacific Environment Group and has not been afraid to speak out, calling China's plan to build nuclear reactors "irrational and undemocratic". In a country where environmentalism is practically non-existent, Bo allocates charitable grants to grassroots environmental organisations, laying the groundwork for a future generation of NGOs and environmental awareness to flourish.
The physicist and environmental activist Vandana Shiva has gained worldwide recognition for her tireless campaigning against the destructive forces of economic globalisation. Shiva has sought to establish a new analysis of economics and development with fairness and sustainability at its heart.
Her work on agriculture in developing countries and the role of women in poverty reduction has provided an invaluable critique on the impact of misguided development solutions. In a report called Making Poverty Inevitable in 2005, she highlighted the damaging consequences of the EU's free trade policies on the developing world - in particular, World Trade Organisation-led initiatives that push millions of poor farmers off their land.
Shiva's particular focus on women and the environment, and her work to promote micro-finance schemes to help women set up businesses, put her at the forefront of the eco-feminist movement. As well as serving as an adviser to governments and NGOs, including the International Forum on Globalisation and the Women's Environment and Development Organisation, she founded the Research Foundation for Science, Technology and Ecology. This led to the creation of Navdanya, a network of seed keepers and organic producers across 16 states in India that establishes community seed banks, trains farmers in sustainable agriculture and promotes fair-trade organic production.
Additional research by James Burgess, Stephen Morris and Samira Shackle