Do many environmentalists hold anti-scientific positions? This idea, put forward by environmental journalist Fred Pearce and others, may have received some pushback (eg Anne Chapman earlier in this series) but for me, it is merely a statement of the obvious.

Consider that great scientific battleground of the early 21st century: embryonic stem cell research. Here is an issue where too many greens hold views indistinguishable from those of the Vatican. Greenpeace brought and won a lawsuit against the German scientist Oliver Brüstle who wanted to patent a method of turning human embryonic stem cells into neurons. In a debate with writer and neuroscientist Kenan Malik Greenpeace claimed they were not opposed to embryonic stem cell research. Yet their own press release at the time made it clear that they were opposed to it.

Until 2010, the UK's Green Party had rather unambiguous views on the issue too: they wanted an EU wide ban on embryonic stem cell research. Parts of a statement from Caroline Lucas were reminiscent of the religious right:

Personally, I remain concerned about the associated health risks, the commodification of eggs and embryos, and the potential exploitation of women. Increasing research suggests that there are a number of promising alternatives, for example adult stem cell research, and umbilical cord stem cell research.

Exactly what did Lucas think the associated health risks are in attempting to cure debilitating diseases? To me, this is not merely anti-scientific, it is morally repugnant.

And let's not forget the fondness of some environmental groups for destroying trials of genetically modified crops. Whether it is Monsanto or government scientists doing the research there always seems to be an environmentalist or two thinking of doing some uprooting. And we are not talking about fringe lunatics here. Last year's failed attempt to destroy a trial of GM wheat in Rothamsted was supported by both the Green Party's candidate for the London mayoral election and their current leader Natalie Bennett.

Greenpeace has a much richer history of ripping up GM crops. For some the defining image of Greenpeace campaigning may be brave activists climbing Europe's tallest building, for me it is grown adults wearing hazmat suits to destroy crops they have no reason to be afraid of.

That Greenpeace takes a dogmatic, not a scientific, approach was made clear when Lord Melchett, then director of Greenpeace UK, made the following statement on opposition to GM crops whilst appearing in front of the House of Lords:

It is a permanent and definite and complete opposition based on a view that there will always be major uncertainties. It is the nature of the technology, indeed it is the nature of science, that there will not be any absolute proof.

Such statements would make even religious dogmatists blush. The UK's main organic farming group, the Soil Association, naturally did not mind such dogmatism: they made Melchett their policy director.

Our choices about the future of energy supply need to be based on solid evidence, yet let's consider the UK Green Party's attitude to the evidence about nuclear power. In 2003 they published a report, enthusiastically endorsed by Caroline Lucas, that claimed "radioactive releases up to 1989 have caused, or will eventually cause, the death of 65 million people worldwide." The research into this report was written by the rather absurd figure of Chris Busby, who apparently for many years was the Green Party's main "expert" source on nuclear issues. I put scare-quotes round expert here for in late 2011 he was exposed for attempting to sell ineffective "anti-radiation" pills to people in the Fukushima region. For years the Green Party grounded their opposition to nuclear power in junk science, and it appears it still does.

If all of this leaves you unconvinced of the marriage of irrational, unscientific, and unethical attitudes by many green organisations then you should read about the history of opposition to golden rice, an innovation that has the potential to greatly reduce human suffering.

I could go on, but I think my point is made. However, I will have to say something about the inevitable resentment these comments will elicit from some readers. Am I not playing into the hands of the climate change sceptics by saying environmentalists are not consistent on science? No, I am not. Environmentalists who say we should accept the scientific consensus on climate change while telling us to ignore it on other issues are the people who are playing into the hands of those who oppose action on climate change. Because if we are to win the fight against climate change we will need to replace ideology, wishful thinking and spin with sober analysis. As the great physicist Richard Feynman said, reality must take precedence over public relations.

This post is part of a series on science and the green movement following debate at this year's Science in Public conference.

Robert Wilson is a PhD student in mathematical ecology at the University of Strathclyde, and writes at The Energy Collective.