May 12, 2014
By Lexi Shultz, Director of Public Affairs at the American Geophysical Union
and Kat Compton, Public Affairs Intern
As if the recent reports from the Intergovernmental Panel on Climate Change (IPCC) and the National Climate Assessment (NCA) weren’t enough of a reminder of the ways in which human actions are changing our planet, new research published in the current edition of Geophysical Research Letters (GRL) presents evidence that part of the West Antarctic Ice Sheet has passed a tipping point. The glaciers in the Amundsen Sea sector of West Antarctica are melting at an unprecedented rate, they’ll be gone within the next few centuries, and there’s nothing we can do to stop their disappearance. These glaciers contain enough ice to raise the global see level by 4 feet (1.2 meters), and even if it takes two centuries, that’s still one foot of sea level rise every 50 years. These are the sorts of findings that take your breath away, or at least they did ours.
The NCA report projects between 1-4 feet of sea level rise by 2100, but Eric Rignot, lead author of the GRL study (of NASA’s Jet Propulsion Laboratory (JPL), Pasadena, California, and UC Irvine), says that due to the study’s findings these projections will need to be revised upward. According to their findings, the West Antarctic glaciers alone will contribute to global sea level rise at the upper bounds of the NCA projections, and that’s before factoring in melting from East Antarctica and Greenland. This GRL study follows on the coattails of another study published in Nature Climate Change on 4 May, which says that the East Antarctic is vulnerable to the same kind of tipping point. If such a tipping point were reached, the East Antarctic could contribute as much as 10-13 feet (3-4 meters) to global sea level rise.
The implications of 4 feet (or more) of sea level rise are a little unnerving. According to the NCA, nearly five million people in the U.S. live within 4 feet of the current sea level. FIVE MILLION. Beyond the obvious loss of coastal real estate and the disappearance of wetland habitat, sea level rise puts communities at risk for severe flooding during storm surge events like those associated with Hurricane Katrina and Super Storm Sandy. Tsunamis generated from large earthquakes will reach communities we have traditionally thought of as safe. How can we respond? Should we start building up our sea walls? Should we rezone coastal real estate and prevent future infrastructure development in vulnerable areas? Should we modify our building codes to reflect the inevitable changes in our environment? What will the economic effects of our choices be? It’s these and similar questions that we aim to tackle during this year’s Climate Change and Natural Hazard Preparedness sessions during the AGU Science Policy Conference in June.
Whatever we decide, now is the time for our government – federal, state, and local – get more serious about the development and implementation of policies that will keep communities safe and resilient. Of course, policies that curb our emission of green house gasses like carbon dioxide are important to help curtail the future effects of climate change. But, at least in the case of sea level rise, research like this demonstrates that we’re not going to be able to stop many of the effects of climate change. That makes preparation and adaptation all the more important. We have to start preparing for the “when.”
AGU’s goal is to help facilitate the conversation between scientists and the decision-makers grappling with the policy implications of our changing climate. This dialogue is key to developing sound policy that will ensure community resilience. We know that many of you are already doing that on your own, and we want to hear from you. Tell us about how you’re contributing to the conversation! Share your experience with us using the Sharing Science tool on our website or leave a comment below.