Let me be clear. The environmental movement needs to change. The world is radically different than it was in the 1960's and 1970's when the modern movement was formed. The environmental movement needs to mature its view of the role of people, technology and corporations. People are the solution not the problem. Technology and innovation allows us to survive on a resource-limited planet. Big corporations are not always the enemy.

But the filmmakers of "What the Green Movement Got Wrong", in their exuberance to make their point, blamed environmentalists for starvation in Africa and energy scarcity throughout the world. That blame is misplaced. Of all those at fault for drought and food shortage in Zambia, environmentalists rank low on the list. The environmental community has been too short on solutions, but to view the environmental movement as a shadow government is to badly misread reality. Indeed, environmental groups have raised the alarm about food and energy scarcity. To blame environmentalists for the problems they identify is like blaming women for misogyny. My mentor David Brower, a legendary American environmentalist, liked to say that "politicians are like weather veins and our job is to make the wind blow." Environmentalists attempt to move public opinion, they don't set public policy. The environmental community can hardly be blamed for the lack of transparency in the nuclear and biotech industry that has been at the heart of public concern.

That I and other lifelong greens have critiques of the environmental movement is no secret; in 2004 I gave a widely-circulated speech entitled "Is Environmentalism Dead?" But as I shared with the filmmakers in footage not selected for broadcast, I am and have always been a passionate supporter of the very groups I criticize. They have been the thin green line that has blocked short-sighted politicians and corporations from turning our last wild forests into toilet paper, our last whales into sushi, our atmosphere into an open sewer. While I have disagreements with Stewart Brand, I have always respected him and I'm the first in line to say that the environmental movement needs to review its most sacred beliefs. But this film misses the mark.

Stewart Brand ends the documentary by demanding that we set aside the joys of ideology and romanticism. But this is one of the most romantic and ideological films I've ever seen. It expresses the profoundly romantic belief that technology alone can solve political and economic problems, and suggests that we needn't make hard choices, such as restraining consumer demand. The idea that wealth and power don't have to be confronted to protect the environment and to ensure that everyone is fed is deeply ideological. It's a convenient ideology - if you're trying to rub along well with corporations and governments. Brand's approach, which the film is based on, is not so much a new form of environmentalism as a new form of corporate consultancy: he appears to be seeking to shape the environmental debate to suit the businesses he works for.

What the Green Movement Got Wrong' posits that the anti-nuclear and

anti-GM crops stance taken by some environmentalists has been

counter-productive. This is, in my view, very much a debate the

environment movement needs to have.

Far less positive it its inference that environmentalists have dealt with

climate change in a counter-productive way. This assertion is poorly

based, and moreover lets the climate sceptics, who are really to blame for

our slowness to action, off scott-free.

One of the program's greatest weaknesses is that it uses the terms

'greens' and 'environmentalists' so as to smear the entire movement with

the perceived sins of a few. While regrettable and lazy, it would be a

pity to toss the baby out with the bathwater. I hope that all concerned

with the environment use the issues raised in the program to think more

deeply about what a sustainable future might look like.

As a scientist working for an environmental group, the documentary's proposition that we are anti-science and ideological is simply not one I recognise. The reality is we're pro-science and very pragmatic. Our biggest campaign on climate change would not exist if we didn't hold science in high regard. Our pragmatism in delivering real change means some surprising alliances. We worked with McDonalds on stopping Amazon deforestation and with Coca-Cola on greener refrigeration to protect the ozone layer and prevent climate change. We don't share all the values of these corporations but are pragmatic enough to realise what working with them could deliver. Because of that very pragmatism we've been accused of abandoning our values– so to now be accused of being ideological is bizarre. We are also not ideologicaly or dogmatically opposed to nuclear and GM technologies. We've looked at what they can do and see better alternatives – we believe GM and nuclear would institutionally block those better alternatives from blossoming. But if the evidence changes then so will our position.

If you suggest that it is better to mend a bicycle with a spanner than a fish, does that make you anti fish? Brand and Lynas try to label environmentalists as anti-science and anti-progress. But both they, and the corporate lobbies promoting GM food and nuclear power, fail to acknowledge that the green movement is merely in favour of different applications of science, ones they conclude are more likely to deliver better progress. The question should be, which tool is best for the job? Who holds the fish, and who the spanner? Brand and Lynas are waving fish. A wide range of agro-ecological farming methods coupled with land reform and economic support to small farmers are more proven, more productive and more likely to reliably feed the poor than GM.

And, numerous, quicker, cheaper, safer and more efficient climate friendly energy strategies and technologies than nuclear are available.

The programme had an oddly emotive pitch. Whilst shrouding itself in science, it displayed a very unscientific faith in particular technologies. Considering the multiple other solutions on offer for human hunger and climate change, the curious, unsettling question, left unanswered, is why do GM food and nuclear power get such disproportionate attention?

Last night's Channel 4 documentary was supposed to reveal a radical new approach to saving the planet. But, like the companies peddling the GM and nuclear technologies the programme pushed, it promised much and delivered little.

There's nothing new about GM and nuclear. Both have been around for decades, both are expensive and ineffective and both are distractions. The documentary urged us to engage with technology, science and people to deliver the solutions that are so urgently needed.

But this is precisely the approach that Friends of the Earth has followed for years – focussing on driving the right kinds of changes and winning campaigns that make a real difference on the ground.

After all, it's because of the people who took action with us that the UK has the world's first climate change law, requiring emissions cuts in line with what scientists say is needed. [More from Friends of the Earth]

What the Green Movement Got Wrong" was an insult to the very people it purports to care about. The programme did not include Southern farmers' voices, and implied that Africans do not have the intelligence to think for themselves. The ABN is here to dispel that myth and to tell the film's producers that it is they who have failed to understand the real issues."

I think the programme probably posted a false dichotomy between different parts of the green movement, but it is true that those greens who present apocalyptic visions of temperature feedback loops have the effect of reinforcing the views of the many who tend to view global warming as like death and taxes: inevitable but unpleasant and therefore better not to think about.

However it is not the green movement's positioning per se that is behind the decline in concern about climate change of the last few years (those who think it is happening are down from 91% to 78%): but the media giving disproportionate coverage to the tiny minority of scientists who disagree with it, and a very cold winter, that are more to blame. My personal position is that we need both technology and considerable changes in consumption to cope with it: it is only by avoiding extreme positions (as the public would see them) that one can take people with you.

Luckily the documentary was not a loud "Ha-ha! Green crazies admit they were wrong", as it could easily have been given C4's patchy record on environmental issues, and the anti-Greens amazing ability to turn the facts on their head. The diverse and eclectic 'Green movement' can name some of the century's most passionate, selfless and ultimately foresighted people amongst its ranks. As the documentary showed there have been many successes that we all benefit from. And yes some alarms were sounded without good reason, some perhaps simply too early to be taken seriously.

Yet the larger theme of 'What the Greens got wrong' struck a chord. Not about nuclear energy or GM crops, but about the natural bias towards the 'No' word, the puritanical streak and misanthropy found too often in our ranks. We need whistleblowers, and the 'Greens' have had many. But we also need entrepreneurs. After the 'not this way' MUST come a 'here's a better option'...

The instinctive 'no' of the green movement has been on clear display when it comes to emissions trading. The idea of using the power of markets to protect the earth's ecology is new, radical and full of problems and pitfalls. But we need bold new ideas to move forward. In a crisis all suggested solutions with real potential should be taken seriously. It is clear that a good number of carbon trading's most passionate opponents get their drive not from a reasoned assessment of the pros and cons, but from a raw dislike of capitalism. They are quite simply cheesed off that a system they object to should find a way to adapt to a problem of (perhaps largely) its own making. Shouldn't it rather throw it's hands up 'mea culpa' and humbly beat a retreat? [More from Sandbag]

By 2030, our warming world will have 50% more mouths to feed. To avoid a food crisis without stripping the planet of water and nutrients we have to come up with solutions soon. Redistribution of wealth and food is vital, but might not be possible in the time available.

No one is advocating GM as a magic bullet against world hunger, but to reject the contribution of this technology before we even know what it is capable of would be morally wrong. If science can develop nutrient-enriched rice or drought tolerant maize, how can we justify its dismissal on ideological grounds?

A reliable, sustainable food supply is the common goal of both plant scientists and the green movement; climate change and a growing population are our common concerns. We cannot afford the luxury of fighting over individual technologies such as GM; to succeed we must work together with every tool at our disposal. Let us do the research.

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Rowan Davies

Gaia Foundation

Bianca Jagger

'Evil Esther'

• Stewart Brand and Mark Lynas were contacted for this article but were unable to respond in time for publication.