Ice scientists say they worry most about the Thwaites glacier in Antarctica and how much the melting ice shelf can add to already rising seas. So a team of 32 scientists are heading by boat to the place where Thwaites hits the warming ocean to scope out how much ice the glacier could lose in the future. It’s already dumping 50 billion tons of ice into the water each year but it is accelerating. Another team is exploring the glacier’s edge _ which is cracking in hundreds of pieces like a damaged car windshield _ by land.