It used to be the biggest question, but now it seems to be the forgotten question of the environment movement: can economic growth continue indefinitely? And this weekend it's going to be brought back into the spotlight at a major international gathering co-sponsored by The Independent.
For three days from today, politicians, environmentalists, writers and thinkers from Britain, France and Italy will gather in the French city of Lyon to debate the idea of "A Sustainable Planet". Sustainability: that's the forgotten issue which until a decade ago was the green movement's major concern. Can we provide for our needs now, in the present generation, without ruining the prospects of the generations of the future?
It's absolutely central, yet in recent years environmental campaigners seem to have become entirely preoccupied with global warming, to the extent that the environment movement has more or less morphed into the climate change movement.
This is perfectly understandable, as the climate threat is a terminal one. But it does mean that some other vital green issues have been shifted into the background, such as the worldwide threats to wildlife, and the question of sustainability and sustainable development, which ultimately is concerned with economic growth.
Economists may think of growth as endless, but the fact is that the Earth is finite, and sooner or later, as the human population soars towards nine billion, limits will be reached. In fact, in some areas, such as the exploitation of fish stocks, they have been reached already. Can we go on like this? In the Sustainable Planet Forum, which has been organised by the The Independent, the French newspaper Libération and the Italian daily La Repubblica, we will be examining the proposition in depth with more than 150 participants in three days of debates, opinion and exchanges.
French speakers known in Britain include the openly gay mayor of Paris, Bertrand Delanoë, who beat Boris Johnson to the idea of free bikes in London, and will speak about cities facing up to the environmental challenge, Jack Lang, the former culture minister, who will debate the idea of "Who benefits from creation?", and Yann Arthus-Bertrand, the photographer who, in recent years, through his aerial photographs of threatened landscapes, has become France's best-known environmental champion, a sort of cross between David Attenborough and Jonathon Porritt.
Eight of Britain's leading environmental thinkers will be taking part: Caroline Lucas, leader of the Green Party and Britain's first Green MP; Porritt, who until last year was chairman of the Government's green advisers, the Sustainable Development Commission; Lord Melchett, policy director of the Soil Association, the lobby group for organic agriculture and food; Tom Burke, the Government's green adviser; Tony Juniper, the leading green writer and campaigner; Andrew Simms, the policy director of think-tank the New Economics Foundation; Peter Ainsworth, the former Tory shadow environment secretary; and Myles Allen, leading climate scientist at the University of Oxford.
These individuals have vast experience of environmental campaigning: three of them are former directors of Friends of the Earth (Burke, Porritt and, most recently, Juniper), while one (Lord Melchett) is a former director of Greenpeace. All of them are passionately concerned with the idea of "A Sustainable Planet" but they will all highlight different aspects of it.
Porritt's attack on the belief in growth is particularly acerbic. He will tell the conference: "The all-pervading disconnect from the physical reality of what is going on in the world becomes more and more surreal. Cotton prices hit a 15-year high. Emissions of greenhouse gases continue on their relentless upward trajectory. The price of wheat soars as crops are consumed by fires in Russia or devastating floods in Pakistan. Oil prices edge higher as more and more business leaders warn of the growing risks of 'peak oil'. Fisheries around the world report declining catches. Water scarcity affects the lives of hundreds of millions. And the competition for land and access to raw materials intensifies as China goes on a buying spree in Africa, South East Asia and South America."
Porritt also challenges other environmental and social campaigners, saying: "Millions of environmental campaigners seriously believe that we can mitigate climate change, slow the loss of threatened species and habitats, manage chronic water and resource shortages, and put an end to over-fishing and continuing soil erosion, whilst sticking with pretty much the same kind of economic growth that brought these natural systems to the edge of collapse in the first place. In all honesty, they're mad."
Juniper will be saying that we have to work with business, but a great deal needs to be done to make business "think ecologically", and Ainsworth will be giving a practical politician's view and saying that growth cannot be discarded, as it is what too many people want, but we have to find was of mitigating its effects.
In three other illuminating talks, Burke will be arguing that we do not need nuclear power to fight global warming, Lord Melchett that there is no future for GMOs, and Dr Allen that we need less government in the battle for the climate (Dr Allen's contention is that the way to solve the problem is to make carbon capture and disposal mandatory as a condition of mining or importing fossil fuels – rather than endless government initiatives).
The British green movement is thus coming together to address once more the somewhat forgotten issue of sustainability, and we consider these contributions so significant that we will be publishing them in full in a special supplement to The Independent next Wednesday. In the meantime, we will be reporting from Lyon on the three days of environmental debate, exchanges, and, as the French like to say, "engagement".
Seen from above, the beauty and vulnerability of the planet
The Earth From Above: that was the simple but brilliant idea of Yann Arthus-Bertrand, a French photographer who realised we could see the beauty of the world in an entirely fresh way though aerial photography.
The loveliness of cherished landscapes, and also their vulnerability, becomes even more evident when they are seen as a whole, and from a wholly different angle, as Arthus-Bertrand made instantly clear when his picture inventory, largely taken from hot-air balloons, was published more than a decade ago. Since then, The Earth From Above – "La Terre Vue Du Ciel" in French – has sold more than three million copies and has been translated into more than 20 languages, but it has done more than make him famous: it has inspired him to become France's best-known environmentalist.
In a country not renowned for its green activism, Arthus-Bertrand, now 64, has become a one-man French crusade to defend the environment, through his charity and website GoodPlanet, which distributes free posters to French schools, produces videos and organises photographic exhibitions, as well as providing environmental news and advice.
Arthus-Bertrand was one of the first people in France to promote carbon offsetting as a way of compensating for the CO2 emissions from the helicopters he sometimes uses for his photography. A measure of his influence is that when he gave a press conference at last year's failed Copenhagen Climate Summit, it was packed: there was no other comparable French voice who people wanted to hear.
A former actor – his film-star good looks may be greying now, but they have lasted – he left the industry in 1967 to run a wildlife park in central France, and later went to live in the Masai Mara national park in Kenya, where he discovered his passion for photography.