The oceans control climate change. Not only do the world’s waters absorb the bulk of the extra heat trapped by greenhouse gases in the atmosphere, they also absorb the bulk of the extra carbon dioxide. And that means one thing: a more acid ocean.
Warmer water also takes up more space. That’s led to sea level rise of 17 centimeters over the 20th century, enough to erode or submerge some 60 extra feet of beach on the U.S. East Coast.
Nothing agreed in Copenhagen or hereafter will be able to stop either this thermal expansion of the seas or the rising acidity of the waters. That would take actually reducing the amount of CO2 in the atmosphere, perhaps through devices to pull it out of the air.