Experimental Fix to Melting Ice Sheets

Is there a cost to global sea level rise? Yes, approximately $50 trillion per year in damages.  The infrastructure needed to create and maintain sea walls and flood defenses cost tens of billions of dollars a year according to John C. Moore. What is adding to the cost? The infrastructure costs approximately $20-33 billion to build. For the installment of the Three Gorges Dam in China spend $33 billon to construct the dam.

Most of the water from sea level rise will come from the melting ice sheets in Greenland and Antarctica.

In their research, they explore three ways we can delay the loss of ice sheets. They suggest to block warm water, support ice shelves, and dry subglacial streams. Note that all of these potential solutions could disrupt natural ecosystems, fisheries, tourism, and water flow. However, Moore and his co-authors argue their solutions may be worth the risk to the present dilemma in the rise of global sea levels.

To block warm water from the Atlantic Ocean, the authors suggest constructing a 100-meter-high wall with sliding sides along the 5-kiometer fjord in front of the Jakobshavn glacier near western Greenland. A fjord is a narrow inlet with steep sides or cliffs created by a glacier. The importance of this project would be similar to other large civil-engineering projects like the Suez Canal in Egypt, Hong Kong airport, Three Gorges Dam in China. However, this project would need 0.1 cubic kilometers of gravel and sand compared to 1, 0.3, or 0.028 cubic kilometers of material needed for the projects in Egypt, Hong Kong, or China.

The Jakobshavn glacier is one of the fastest moving ice masses on Earth, and it contribute to most of the sea level rise than other glaciers located in the Northern Hemisphere. Furthermore, 4% of twentieth century seal level rise can be attribute to this glacier.

For their second solution, Moore and his co-authors they would construct a berm (raised banks bordering river or canal) and islands to artificially pin ice shelves in front of the Pine Island and Thwaites glaciers in West Antarctica. Ideally, this would temporary prevent the movement of the glacier. Similar to the first plan, these materials need to be outsourced to material to build the berm and island.   Models predict that Pine Island Glacier and Thwaites will be the largest source of se level rise in the next two centuries, contributing 4 centimeters a year.

For dry subglacial streams, they want to reduce the rate of melting by removing the glacier’s ice bed to reduce frictional heating in Antarctica. When they remove the ice bed, they will use a pumping station to extract or freeze the water at the glacier’s base to slow sliding. This process would be important to mitigate sea level rise because glacier ice beds supply 90% of ice in the sea.

With this intensive construction and extraction of materials, do their plans sound plausibly or worthwhile? The authors leave it to other glaciologist and engineers to test their projects.  Also, if this plan does carryon, who will need to approve this project? This project may result in global consequences if they do not structure it properly. What are your thoughts on this project?

Source:

Moore, John C. et al. 2018. Geoengineer polar glaciers to slow seal-level rise. Springer Nature 555: 303-305.