“On the one hand, as scientists we are ethically bound to the scientific method, in effect promising to tell the truth, the whole truth, and nothing but – which means that we must include all doubts, the caveats, the ifs, ands and buts. On the other hand, we are not just scientists but human beings as well. And like most people we’d like to see the world a better place, which in this context translates into our working to reduce the risk of potentially disastrous climate change. To do that we need to get some broad based support, to capture the public’s imagination. That, of course, means getting loads of media coverage. So we have to offer up scary scenarios, make simplified, dramatic statements, and make little mention of any doubts we might have. This “double ethical bind” we frequently find ourselves in cannot be solved by any formula. Each of us has to decide what the right balance is between being effective and being honest. I hope that means being both.”

Or they could, erm, actually be inflammatory. -Kate

Projections are not the same as predictions. Projections are calculated using a range of hypothetical values for different factors influencing the result if don’t yet know what path these factors (often societal in nature) will take. Predictions are made when scientists have confidence in what path they will take.

In the case of Ehrlich, society managed to prevent these influencing factors from creating a worst-case scenario. Therefore, it is misleading to say that his projections, which were based on hypothetical values, were incorrect. Let me know if you find a peer-reviewed modelling simulation (probably a biogeochemical model for DDT in the oceans, I’m not sure what kind of model would be used for agricultural production) that uses the same worst-case values for influencing factors, but has a less extreme outcome than Ehrlich found. -Kate

The point is that a sufficiently motivated and scientifically informed society and its governments can act in the general good. I suspect that if we were to try and ban DDT today that we would face a similar barage of claims and counter claims as occurs now with AGW, but fought over the internet, not debates brought forward by placard-carrying university students and others at rallies, or book signings (Rachael Carson’s ‘Silent Spring’). And funding for the science behind the green revolution would be opposed because ‘why should my taxes be used to feed people in a Muslim country?’

An unfortunate consequence of the green revolution was a heavier reliance on chemical fertilizers, pesticides and herbicides, some of which are made from fossil fuels, making agriculture increasingly reliant on oil products.

I obtained some of the above from the US EPA here: http://www.epa.gov/history/topics/ddt/01.htm
and a Wikipedia article here: http://en.wikipedia.org/wiki/Green_Revolution