"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 the
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 climatic change. To do that we need to get some broadbased support, to capture the public's imagination. That, of course, entails 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."
As quoted from his own website:
http://stephenschneider.stanford.edu/Mediarology/Mediarology.html