Recent dramatic events in the Arctic and Antarctica are supporting scientists who suggest that the pace of climate change is accelerating. The Arctic ice cap is thinner than ever, with ice older than two years comprising less than 10 percent of the ice cover in measurements from the end of February. The amount of thick sea ice hit a record wintertime low of 378,000 square miles, which is down by 43 percent over the last year. As old ice is the thickest, and slowest-to-melt, it plays a vital role in regulating temperature on Earth.
“That thick ice really traps ocean heat; it keeps the planet in its current state of balance,” says Waleed Abdalati, director of the Center for the Study of Earth from Space at the University of Colorado and NASA’s former chief ice scientist. “When we start to diminish that, the state of balance is likely to change, tip one way or another.”
While 2008 was a comparatively cool year worldwide, and 2009 and 2010 predicted to be much warmer, the concern is that arctic sea ice will retreat dramatically — exceeding record losses that occurred over the last two years. Sea ice is important because it reflects sunlight back into space, and helps turn down the Earth’s thermostat. As the ice melts, the dark ocean waters will absorb unprecedented amounts of energy, which will accelerate the thawing of the permafrost, potentially releasing billions of tons of methane ― a greenhouse gas 21 times more potent than CO2 — into the atmosphere. Warming begets warming.
In similar news, the map of Antarctica will need to be redrawn, as the thin bridge holding back the Wilkins ice shelf from the sea snapped earlier this week. The Connecticut-sized ice shelf is now expected to disintegrate, turning the Charcot Island into a true island. Although this single event won’t affect sea level, it demonstrates that Antarctica is melting three or four generations ahead of schedule. It also threatens to speed the flow of continental glaciers to the ocean, and that will affect sea level.
* Climate change deniers like to think that we’re heading for another ice age despite all evidence to the contrary. Over the last two years, Arctic amplification has dramatically increased ice melt in the Arctic, but every winter — just as you’d expect — the ice refreezes. And so they run a story every month headlining the dramatic increases in Arctic sea ice over the winter.
It would be laughable if it wasn’t so serious. What matters in the Arctic isn’t the extent of sea ice, but the volume. And the graph above — from researchers at the National Snow and Ice Data Center explains the problem perfectly.