Discussions about global warming often focus on the impact of warmer global temperatures on Antarctica, and for good reason - most of the world's ice is in Antarctica, so if the continent warms up and melts, ocean levels will most certainly rise. Which is why this week's news that the entire West Antarctic Ice Sheet (WAIS), which contains enough water to raise sea level by five meters or so, could melt over the course of the next thousand years only somewhat comforting. Somewhat because the research revealed that the ice sheet had melted and regenerated many times, meaning that there is a definite precedent for the complete disappearance of the WAIS. Scientists knew that the sheet wasn't always the same size, but didn't necessarily have proof that it could melt entirely. Now they do, and it is certain that such melting would submerge many of the world's major cities.
While the WAIS is important, it's not the only source of sea-level raising ice. Antarctica as a whole is losing ice at the rate of 36 cubic miles per year. Though we may not be around to see the kind of catastrophic rise in sea level that would accompany the complete melting of the WAIS, we need to know the costs of allowing global warming to proceed unchecked.