Sea level rise is primarily caused by two factors related to global warming: the added water from melting ice sheets and glaciers and the expansion of seawater as it warms. From 1992 through 1997 the annual loss of ice in Antarctica was equal to 49 billion tons; by 2012 through 2017, the annual loss had increased to 219 billion tons. By the turn of the next century, global sea levels will have risen by one to four feet, potentially turning hundreds of millions of people living in coastal regions into refugees.
