A warming climate is more like walking across an ice-covered lake toward an area where the water is open and unfrozen. With every step you take, the ice grows thinner. But you tell yourself that the decrease in the thickness of the ice is gradual, and it seems like the ice will continue to hold. You've had no problem so far, and so, denying the dilemma you are in, you take another step. But the truth is, things can change abruptly, dramatically, and fatally. It is likewise with global warming. Changes seem to be happening slowly, barely perceptibly, but assuming that the small changes you see accumulating around you do not increase the risk of catastrophe is a dangerous delusion. At some point, abrupt change will happen, dramatically changing the planet we live on.