The burning of fossil fuels has altered the amount of carbon dioxide in the atmosphere so rapidly and so abundantly that now, we are driving not just the warming trend, not just the sea level rise that is a consequence of the warming trend that is melting polar ice and alpine ice, but also [ocean acidification].

You should know what is taken out of the ecosystem in order to give you a moment's sustenance.

If Darwin could see what we now see, what we now know about the ocean, about the atmosphere, about the nature of life, as we now understand it, about the importance of microbes - I think he would just beam with joy that many of the thoughts and the glimpses of the majesty of life on Earth that he had during his life, now magnified many times over.

In the past few decades, Earth's natural systems have endured more pressure than in all preceding human history.

If I seem like a radical it's because I have seen things that others have not.

We've got to somehow stabilize our connection to nature so that in 50 years from now, 500 years, 5,000 years from now there will still be a wild system and respect for what it takes to sustain us.

When I arrived on the planet, there were only two billion. Wildlife was more abundant, we were less so; now the situation is reversed.