Man has been endowed with reason, with the power to create, so that he can add to what he’s been given.But up to now he hasn’t been a creator, only a destroyer.Forests keep disappearing, rivers dry up, wild life’s become extinct, the climate’s ruined and the land grows poorer and uglier every day.

Chekhov, Anton

This is a beautiful planet and not at all fragile.Earth can withstand significant volcanic eruptions, tectonic cataclysms, and ice ages.But this canny, intelligent, prolific, and extremely self-centered human creature had proven himself capable of more destruction of life than Mother Nature herself….We’ve got to be stopped.

Fischer, Michael L.

Our environmental problems originate in the hubris of imagining ourselves as the central nervous system or the brain of nature.We’re not the brain, we are a cancer on nature.

Foreman, Dave

The struggle to save the global environment is in one way much more difficult than the struggle to vanquish Hitler, for this time the war is with ourselves.We are the enemy, just as we have only ourselves as allies.

Gore, Al

this is a few i assumed have been particularly exciting: we are enjoying Russian roulette with valuable properties of the planet’s ecosystem which will profoundly effect generations to return. How long are we prepared to gamble? — David Suzuki As further and extra human beings understand what’s at stake, they strengthen into area of the answer, and share the two interior the stressful circumstances and possibilities provided by ability of the climate crises.– Al Gore and then there is this question of what to do. human beings do no longer want to confront issues they have not got a clean answer to. And the solutions here—to the quantity there are suggestions—are very, very complicated.– Elizabeth Kolbert all of us understand the technological know-how, we see the possibility, and all of us understand the time for action is now. — Gov. Arnold Schwarzenegger climate substitute is and could be an important danger to our national secure practices and in a larger sense to existence on earth as all of us are conscious of it to be. — Gen. Gordon R. Sullivan, retired , former U.S. military chief of artwork stress

Knock yourself out … see below. I like the first one in the list

“Humanity is conducting an unintended, uncontrolled, globally pervasive experiment whose ultimate consequences could be second only to a global nuclear war. ”

Statement by WMO, UNEP, and Environment Canada at The Changing Atmosphere: Implications for Global Security Conference, Toronto, June 1988.

I also think the date of the stement is significant, almost 15 years before this became a hot topic.