New research finds ice sheets in Greenland and Antarctica melted at a far faster rate than previously believed at the end of the last ice age, raising fears that global sea level rise could rapidly accelerate this century as modern-day glaciers collapse due to human activity. The report in the journal Nature found the Norwegian continental ice shelf retreated by as much as 2,000 feet per day. The findings came just days after another study in Nature found melting ice could soon cause deep ocean currents around Antarctica to collapse, with dire effects on the oceans and Earth’s climate that could last centuries. The collapse could play out on a scale of just decades or even years.