According to a new study, if we can’t keep global temperatures from rising less than 2 degree Celsius we could be in for hundreds, if not thousands, of years of sea level rises as the Antarctic ice shelves collapse. We’ll have to significantly reduce emissions by 2020 in order to do that, but even then, we’re looking at about 25 centimeters of sea level rise by 2050, and about 50 centimeters by 2100. That’s half a meter higher, and at current, about 10% of people in the world live within 10 meters of sea level.
The new study takes into effect newer discoveries about how Antarctic ice shelves interact with water, which in steadily increasing in temperature across the globe. If those shelves start to melt, it will begin a chain reaction that will dump a lot more water into the ocean than we can afford to deal with.
The last time the Earth was in a similar position, about 3 million years ago, global temperatures were about 3 degrees Celsius higher than they are now. At that time, the Antarctic sheet was much smaller than it is now, and sea levels were about 20 meters higher than they currently are. Without some serious work to reduce emissions, that’s where we’re headed, and likely soon as well.
The study raises a pressing ethical question, namely: are we going to actually do something to curb emissions, or are we going to adapt to a world with significantly higher sea levels? In all likelihood, we’d better do both. Even if we do manage to reduce carbon emissions and keep things from reaching a point with 10 or 20 meter higher sea levels, we’ve done enough damage that we will be facing at least slightly higher sea levels. The question is not will sea levels rise, but how much higher will they go?