This is a reconstruction from notes of a keynote address delivered to the Power Shift West Conference, Eugene, Oregon, November 5, 2011.
All of us here today, along with countless others around the world, are currently engaged in the collective struggle to save the planet as a place of habitation for humanity and innumerable other species. The environmental movement has grown leaps and bounds in the last fifty years. But we need to recognize that despite our increasing numbers we are losing the battle, if not the war, for the future of the earth. Our worst enemy is denialism: not just the outright denial of climate-change skeptics, but also the far more dangerous denial — often found amongst environmentalists themselves — of capitalism’s role in the accumulation of ecological catastrophe.1
Recently, climate scientists, writing in leading scientific journals, have developed a way of addressing the extreme nature of the climate crisis, focusing on irreversible change and the trillionth ton of carbon. Central to the scientific consensus on climate change today is the finding that a rise in global temperature by 2° C (3.6° F), associated with an atmospheric carbon concentration of 450 parts per million (ppm), represents a critical tipping point, irreversible in anything like human-time frames. Climate models show that if we were to reach that point feedback mechanisms would likely set in, and society would no longer be able to prevent the climate catastrophe from developing further out of our control. Even if we were completely to cease burning fossil fuels when global average temperature had risen by 2° C, climate change and its catastrophic effects would still be present in the year 3000. In other words, avoiding an increase in global average temperatures of 2° C, 450 ppm is crucial because it constitutes a point of no return. Once we get to that point, we will no longer be able to return, even in a millennium, to the Holocene conditions under which human civilization developed over the last 12,000 years. Many of you are aware that long-term stabilization of the climate requires that we target 350 ppm, not 450 ppm. But 450 ppm remains significant, since it represents the planetary equivalent of cutting down the last palm tree on Easter Island.2.