Winter has finally arrived, and a light dusting of snow brings out the kids in my neighbourhood. As they roar around with cheeks red and coats flapping open, their joy always helps me through the time of ice and darkness.
That and the knowledge that it's precisely this dance of hot and cold that creates the astounding range of life forms on earth, from tropical to boreal forests to the unbelievably fertile polar oceans.
The oceans at the edge of the ice caps are richer in oxygen than tropical waters, and contain 20 times the number of microscopic plants and animals. These tiny plankton feed everything from clams and fish to the blue whale, the largest animal that ever lived.
The ice pack itself, growing in winter and shrinking in summer, is a floating platform for fishers like polar bears, seals and walruses.
I'm not a fan of the cold. Cold hurts. Cold kills. To survive winter, people had to learn to control fire, creating miniature suns fuelled by wood, coal and oil. We carried these smoking suns with us into the far reaches of livability, places like Canada, where ice rules for a good part of the year.
Or used to.
By the end of the day, the kids' sliding hill has been rubbed bare of both snow and vegetation. They return to ball hockey and tag, hoping for more winter. I enjoy these lovely days, but they worry me.
Who would have thought that human activity could threaten a glacier, let alone the polar caps of ice that air-condition our planet? As our fuel-burning weaves a blanket of carbon dioxide to hold in the sun's warmth, the poles are the areas where change is greatest.
The melting of the ice caps even threatens the existence of ocean currents. The planetary dance of hot and cold creates those rivers in the sea that feed and cool the tropical coral beds, then turn around to warm continental coasts on their way back to the poles.
On a warm winter day, the kids drag me over to a tree to show me a fly clinging to the bark: "Where did it come from?" they ask. "Why doesn't it fly away?"
Known locally as the bug lady, I'm supposed to have all the answers. I tell them it might have been sleeping under the bark. It's warm enough today to wake the insect, but still too cold for it to fly. They want to know what will happen to it.
I don't know the answer to that. I don't know what happens to peregrine falcons and flies that hang around Toronto playgrounds in December, nor to willows that bud in January. So the six-year-olds take matters into their own hands. When my back is turned, they take the fly inside and let it go.
Children don't know that as the great global diversity of life narrows because of human activity, flies and rats will thrive while a million amazing species will be lost forever. But they know that a fly can suffer. They'd keep a blue whale in their bathtubs if they could, but it's not up to the kids to stop the madness. By the time they come into their power, it will be too late.
We are the generations that have to make it right. The air-conditioned, affluent, SUV-driving, overworking, overproducing, over-consuming, ears-full-of-electronic-plastic, video-game-thumbing, cellphoning, golf-elbow generations: the baby boom, X and why? generations.
It's up to us. We can wrap ourselves in distractions and hide from climate change, but we can't run.