Paul Ehrlich, whose dire warning on the world’s “population bomb” more than 40 years ago still generates debate, is in Australia on a speaking tour. But we might have learnt the most from what the audience said back to him.

From his 1968 book The Population Bomb onwards, Ehrlich has issued dire predictions about the imminent end of human civilization. He still does. Ehrlich, in one of the major set pieces, addressed a packed house in Canberra last Thursday night at the invitation of the Fenner School of Environment and Society.

Whether or not you share his view depends pretty much on the extent to which you feel climate change is both catastrophic and irreversible.  That is so well debated in Crikey that there is no need for more comment. Let’s ask a different question: why are so many environmental scientists apparently determined to discredit themselves?

Ehrlich began his talk by asking why scientists’ voices were not being heard. The gathering of 200-plus science academics and students (and around the same numbers of the general public) unwittingly provided the answer to the question in their own Q&A session after the talk.

Among the various propositions advanced by the audience were a compulsory year of university science for all journalists (anyone want a public interest advocate with coercive powers to enforce that one?), a call for scientists to tell people the planet is dying so as to make them listen (as if prophets of doom get good media) and blaming global warming on the Murdoch and Fairfax press.

For most serious commentators in the MSM, the debate about global warming has been settled. The key issue today is what to do about it, territory that is hugely worth debating. If we were to take the signal from this audience, most Australian scientists see economists as the enemy and want to cut them out of the debate. Hopefully it was not a representative sample.

Ehrlich himself was positive about the contribution that economics could play in solving problems of global warming, albeit claiming “some of my best friends are economists” (unbelievably, he said almost precisely that).

It was in the question time that a number of other scientists talked about “the” economic model. If they had ever interacted with economics they would know that if you gather five economists together you get at least six opinions. For environmentalists, dismissing economics is self-defeating. Unless you change incentives (something economics is good at) you can’t change peoples’ behaviour.

At the end of the session Ehrlich cracked a joke: members of the US Congress had only room temperature IQs — so perhaps global warming would increase them. It attracted a huge round of applause. While it was a moment of hilarity for this audience, one wonders whether gratuitous insults are a good way to persuade a legislature to act on environmental problems.

Yet the consensus amongst this this sub-set of the scientific community seemed to be that the best way to win a debate is to deride anyone who disagrees with you.

The Congress, like our own Parliament, is smart and capable. Members operate in a real world where policy solutions like “people have to stop having children” just don’t work.

For all the deeply held concerns among the many scientists, more realistic solutions were thin on the ground. Most of the comments amounted to nothing more than “somebody should do something”.

There was though a note of reality, fortunately, from the people invited to discuss Ehrlich’s talk. One of the speakers had modelled what would happen if hypothetically every nation had a one-child policy. Even then, assuming children alive today don’t suffer a painful early death, the world’s population would still grow until 2050. Nobody on the panel advocated global infanticide as the solution.

The challenge for environmental scientists is to eschew insulting politicians, journalists, indeed anyone they blame for not understanding the world the same way they do. They cannot hope to win friends by simply shouting louder. That will turn people away.

They need to add another pillar to their argument — practical solutions. Solutions that work in a democracy. Solutions that do not rely on coercion from a benevolent dictatorship of scientists. Until they can do that, Paul Ehrlich’s plaintive question about why scientists are not being heard will continue to answer itself.

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