Washington Post] Sea level rise has been in the news a lot lately. Recent research has raised concerns about the possible collapse of the West Antarctic Ice Sheet and how this could double sea level rise projections for 2100.
level rise is potentially one of the most damaging results of climate
change, but few people understand its risks. Its impacts — financial and
otherwise — will spread far from the coasts.
Here are 10 things you should know about sea level rise, what causes it and how bad it might get.
1. There is enough water stored as ice to raise sea level 230 feet.
of this ice is located in Antarctica and Greenland. Antarctica, with an
area 40 percent greater than the United States, is covered by an ice
sheet almost a mile thick that holds about 200 feet equivalent of sea
level. Most of that ice is — for now — stable, but scientists are
concerned that the massive West Antarctic Ice Sheet, which holds about
11 feet of potential sea level rise, has reached a tipping point and
will collapse. Another 23 feet of equivalent sea level is stored as ice
in Greenland, and it is melting at an increasing rate. The rest is in
glaciers and ice caps spread around the world, and they, too, are
2. Sea levels have changed by hundreds of feet in the past.
generally think of sea level as stable, but sea level has varied a lot
over time as we have gone from ice age to ice age at about 100,000-year
intervals. At the height of the last ice age, when much of North America
was covered in ice, sea level was about 400 feet lower. We are now in a
warm period between ice ages; sea level should be peaking and then
eventually starting to go down again. But human-caused climate change is
altering this cycle.
3. We are changing sea level at a very rapid rate.
sea level has varied greatly in the past, it has generally changed
slowly, over many thousands of years — except when ice sheets collapse.
We will explain more on ice sheet collapse later, but prior to about
1900, we know sea level was stable for several thousand years. A warming
world is now pushing sea levels higher, and the rate of rise is
accelerating. Read More