For a long time now, Earth has been running a fever. Never mind the few remaining climate-change deniers — really, never mind them; the world has at last moved on — it’s getting awfully toasty down here. The numbers tell the story: 2012 was the hottest year on record in the continental U.S., the 15th driest and the second most volatile, with 11 natural weather disasters, including Superstorm Sandy. Of the 10 hottest years on record worldwide, nine have occurred in the 21st century; the exception was 1998. Average temperatures around the world are up 1.4ºF (0.8ºC) since 1880. On a planet whose water-based chemistry tips one way or the other on tiny thermal fulcrums, that’s a lot.
More important than those statistics are our everyday experiences — the droughts and wildfires searing the American West, the succession of 90-degree days in U.S. cities that once enjoyed less-punishing summers, the steadily rising sea levels inundating coasts and swallowing islands. The planet is sweating, and we feel it every day.
Nowhere is the fluctuation in the earthly thermostat more visible than in the Arctic, as the above Timelapse video of diminishing glaciers demonstrates. In just the past decade, the average size of the summer polar ice cap has been slashed nearly in half, from 2.7 million sq. mi. (7 million sq. km) to just 1.4 million sq. mi. (3.6 million sq. km). In some areas, a clear, navigable passage has opened up during the warmest months, and while that may seem good for global trade — and it is — it’s very bad for the health of the planet. The ice that melts off the Greenland landmass is a key contributor to rising sea levels. What’s more, the ice loss is accelerating, and it will continue to do so for quite some time even if global temperatures stopped rising today. That’s because bright white ice reflects sunlight back into space, while dark blue water absorbs it. Every acre of sea that opens up therefore becomes something of a heat sink, raising the water temperature