Here is a very good TED talk by Johan Rockstrom about human pressures, environmental constraints and possible futures.
Now that's a very talented man. He can do the science and he can do the public speaking.
A very polished performance.
The only real flaw in the presentation was that his language was just a bit too corporate and not truly evocative. I have no doubt that it appealed to his audience, but would it resonate with the average man or woman in America or China or Greece? The challenge is to simplify and polish the language without distorting or undermining the urgency of the message. It was otherwise an excellent presentation.