FAS launches Sea Level Investigation and Management project

Can sea level rise be slowed? A new project called Sea Level Investigation and Management (SLIM), made possible by a generous gift from Cornelius “Neil” Prior Jr., LL.B. ’62, aims to find out.

Over pumping of aquifers causes about 10 percent of sea level rise. Peter Huybers, chair of the Department of Earth and Planetary Sciences (EPS), will investigate if flipping the balance between aquifer recharge and withdrawal to instead sequester water on land could slow sea level rise significantly.

“There may be a win-win here where we can help to stabilize and recharge aquifers and help to globally mitigate risks of coastal flooding,” he said.

Sea level declined in 2011 when La Niña caused increased rainfall over land areas such as the interior of Australia, where water flows back into the ocean over an extended period of time. This indicates that sea level can be slowed by retaining more water on land, Huybers said.

SLIM will convene a group of scientists and engineers to explore whether geotechnical approaches (mitigating “wedges”) can be deployed to slow sea level rise. A potential sea level wedge is to reduce over pumping of aquifers by, for example, improving the efficiency of agricultural irrigation systems. The complement of limiting over pumping is to increase aquifer recharge. Recharge can be increased through capturing runoff and allowing for infiltration, as well as by direct injection of water into aquifer systems.

Another wedge may come from filling surface depressions. Some shrinking inland seas (Caspian and Dead seas, for example) suggest an opportunity to pump seawater into these regions to stabilize and replenish their levels.

These concepts are technically challenging due to the massive volumes of water involved. Also complex are the societal trade-offs.

“It has to be considered from the outset that modifying surface and subsurface reservoirs for the purposes of abating coastal flooding might involve difficult trade-offs,” said Huybers, adding that SLIM will collaborate with experts in policy and ethics in the fuller consideration of the feasibility of deploying any sea level management approach.

Several years ago, Prior became concerned that rising sea levels caused by climate change in places like Venice, Miami, and Bangladesh were being neglected compared to the enormous political and financial resources focused on fossil fuels. He created a small nonprofit organization to engage in finding cost-effective solutions. “After several false starts, I was introduced to Professor Huybers, who shared my concern for the problem,” he said.

Prior presented the professor a challenge: to consider how one millimeter of sea level rise could be averted annually through sequestering water on land.

“At first, I was skeptical that anything useful could be done with respect to actively managing sea level rise,” said Huybers. “But after studying the problem for a while, I think sea level management merits serious consideration.”

Said Prior: “My hope is that Professor Huybers’ findings will be broadly applicable and, by raising awareness, lead to solutions for the problem of rising sea level.”