Several times in Earth's history, rapid global warming occurred, apparently spurred by amplifying feedbacks. In each case, more than half of plant and animal species became extinct. New species came into being over tens and hundreds of thousands of years. But these are time scales and generations that we cannot imagine.
James HansenThe greatest danger hanging over our children and grandchildren is initiation of changes that will be irreversible on any time scale that humans can imagine.
James HansenWe have at most ten yearsโnot ten years to decide upon action, but ten years to alter fundamentally the trajectory of global greenhouse emissions.
James HansenThe climate is nearing tipping points. Changes are beginning to appear and there is a potential for explosive changes, effects that would be irreversible, if we do not rapidly slow fossil-fuel emissions over the next few decades.
James Hansen