如果各国履行其在巴黎气候协定下所作出的承诺，海平面的上升幅度有可能被控制在一半左右，更雄心勃勃的计划甚至可能实现更高的目标。
If countries meet their commitments under the Paris climate agreement, the total sea-level rise could be halved, with more ambitious schemes promising even greater reductions.