The truth is that we're at a critical juncture in the history of our species and if we don't act soon, we could inhabit a world we don't recognize anymore.

When it comes to climate, we can all make a big difference. At the most basic level, don't let denial go unchallenged and win the conversation on climate.

Fifteen per cent of the population believe the moon landing was actually staged in a movie lot in Arizona and somewhat fewer still believe the Earth is flat. I think they all get together with the global warming deniers on a Saturday night and party

Atheists have just as much of a right to the public discourse as any ... people of any religious faith in this country.

Third world nations are producing too many children too fast...it is time to ignore the controversy over family planning and cut out-of-control population growth.

Our insatiable drive to rummage deep beneath the surface of the earth is a willful expansion of our dysfunctional civilization into Nature.

The heart of the security agenda is protecting lives, and we now know that the number of people who will die of AIDS in the first decade of the 21st Century will rival the number that died in all the wars in all the decades of the 20th century.