Photo: AP

Great news: A study published Wednesday suggests that the West Antarctic ice sheet, which is larger than Mexico, might begin disintegrating much earlier than expected, possibly raising the sea level across the entire ocean as much as three feet by 2100. (Levels in other areas might rise twice as much.)

This is alarming not just on its face but because this model offers a far more catastrophic understanding of climate change’s imminent effects than previously anticipated. The New York Times reports:

That is roughly twice the increase reported as a plausible worst-case scenario by a United Nations panel just three years ago, and so high it would likely provoke a profound crisis within the lifetimes of children being born today.

The situation would grow far worse beyond 2100, the researchers found, with the rise of the sea exceeding a pace of a foot per decade by the middle of the 22nd century. Scientists had documented such rates of increase in the geologic past, when far larger ice sheets were collapsing, but most of them had long assumed it would be impossible to reach rates so extreme with the smaller ice sheets of today.

If the results are anywhere near correct, and if emissions continue at a high level through the rest of this century, the long-term effect would likely be to drown the world’s coastlines, including many of its great cities.

New York City is nearly 400 years old; in the worst-case scenario conjured by the research, its chances of surviving another 400 years in anything like its present form would appear to be remote. Miami, New Orleans, London, Venice, Shanghai, Hong Kong and Sydney, Australia, are all near sea level and just as vulnerable as New York, or more so.

“We are not saying this is definitely going to happen,” said Pennsylvania State’s David Pollard, one of the paper’s co-authors. “But I think we are pointing out that there’s a danger, and it should receive a lot more attention.” Haha. Great.