He was particularly critical of a Greenpeace stunt which for damaging CSIRO’s GM wheat trials in July 2011, as was Mr Lynas.

The stunt caused about $300,000 damage and resulted in convictions recorded against two Greenpeace employed activists who faced the ACT justice system and received nine-month suspended sentences.

Despite the convictions and paying $280,000 in compensation to the CSIRO, Greenpeace has pledged to continue campaigning against the introduction of GM wheat in Australia, citing issues with safety and environmental concerns.

Professor Langridge said he hoped Mr Lynas' speech would help create greater focus on plant technology science within the Australian GM debate.

“His comment that he had been unaware of most of the science behind GM crops was very revealing," he said.

“It was only when he delved into the science that he realised how seriously misguided and ill-informed he had been (and) I can only hope that other opponents of the technology recognise the need to actually read some of the scientific literature of the topic.”

Croplife Australia CEO Matthew Cossey said Mr Lynas’ speech showed the importance of looking beyond scaremongering tactics and seeking out the established science on GMs.

“Here is a man who questioned his actions and has come out in support of something he tried to destroy,” he said.

“That requires a huge amount of courage but it was unquestionably the right thing to do because the actions of the anti-GM lobby have had serious consequences, especially for the millions of people who go to bed hungry every night.

“It’s a real tragedy that over the past decade many members of our society who have made an effort to engage with the question of where their food comes from have been sold down the river by the emotional manipulation of many green groups.

“There is an ironic tendency amongst many intelligent, educated, progressive Australians to associate “green” with “trustworthy”, rather than thinking critically about what sustainability actually requires.”

Mr Cossey said a respected environmentalist coming out in support of agricultural biotechnology, having informed himself about the science, showed that a turning point had now been reached and “the science is finally getting through”.

“Now we can move onto talking about increasing investment in agricultural research and development and removing unnecessary regulations and cost burdens so research institutions can focus on finding ways for our farmers to produce more with less,” he said.

University of Melbourne senior lecturer in food biotechnology and microbiology, agriculture and food systems David Tribe said Mr Lynas' speech was important in the UK but his ‘conversion’ wasn’t recent and only now getting wide publicity.

Dr Tribe said three or four important environmentalists do speak out about GMs, including author and founder of the modern green movement Stewart Brand, the Nature Conservatory's chief scientist Peter Kareiva and Greenpeace founder Patrick Moore.

“They are all scientists by training,” he said.

“Together these science-grounded greens are an important new movement of modern scientifically savvy greenies.

“Mark's (Lynas) good because he's articulate and young and his environmentalist credentials are very strong because of his activism and books about climate change.”

Dr Tribe said he didn’t think the speech would have much of an impact in Australia, except among the media sector who "will be nudged along a little bit”.

In his speech, Mr Lynas described his anti-GM campaign as “explicitly an anti-science movement”.

“We employed a lot of imagery about scientists in their labs cackling demonically as they tinkered with the very building blocks of life,” he said.

“Hence the Frankenstein food tag – this absolutely was about deep-seated fears of scientific powers being used secretly for unnatural ends - what we didn’t realise at the time was that the real Frankenstein’s monster was not GM technology, but our reaction against it.

“For me this anti-science environmentalism became increasingly inconsistent with my pro-science environmentalism with regard to climate change - obviously this contradiction was untenable.

“So I did some reading and I discovered one by one my cherished beliefs about GM turned out to be little more than green urban myths.”