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Climate Change

Published on March 21st, 2018 | by Steve Hanley

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Scientists Propose Geoengineering Projects To Control Rising Sea Levels

March 21st, 2018 by  


If you don’t believe in climate science, then everything is rosy. We can just continue doing what we have been doing and everything will be fine. Most of us who participate in the CleanTechnica community believe the world is warming, that human activity is largely responsible for the increase in global average temperatures, and that we have a duty to mitigate the changes those higher temperatures will cause. Part of those mitigation strategies may include targeted geoengineering projects to protect against rising sea levels.

Geoengineering to avoid rising sea levels

Scientists at Princeton University are proposing a plan to stabilize the continental ice shelves that extend outward from Greenland and Antarctica. They say focusing on those areas will be less expensive and more effective than building seawalls around continents.

Building Underwater Walls

Michael Wolovick is a postdoctoral research associate in Atmospheric and Oceanic Sciences at Princeton University and the co-author of a recent Comment published by the journal Nature. He suggests building walls beneath the sea to prevent warm water from melting continental ice shelves is a sensible way to slow down rising ocean levels. Those shelves spread out from the land — especially in Greenland and Antarctica — and float on top of the water.
The warmer water from below slowly melts them, adding to the volume of water in the oceans.

Wolovick asks, “Is allowing a ‘pristine’ glacier to waste away worth forcing one million people from their homes? Ten million? One hundred million? Should we spend vast sums to wall off all the world’s coasts, or can we address the problem at its source? Geoengineering is a political and societal choice, because people’s reactions depend on how the issue is framed. Buttressing of glaciers needs a serious look. It should have fewer global environmental impacts than other proposals being discussed for reducing sea level rise, such as injecting aerosols into the stratosphere to reflect sunlight and cool the planet.”

Targeting High Leverage Points

Wolovick says targeting our efforts at specific areas that are high leverage points for controlling the increase in sea level is a much smarter and cost effective approach.

“Geoengineering interventions can be targeted at specific negative consequences of climate change, rather than at the entire planet,” he says. “There is going to be some sea level rise in the 21st century, but most models say that the ice sheets won’t begin collapsing in earnest until the 22nd or 23rd centuries. I believe that what happens in the 22nd or 23rd centuries matters. I want our species and our civilization to last as long as possible, and that means that we need to make plans for the long term.”

He argues that stalling the fastest flows of ice into the oceans would buy us a few centuries to deal with climate change and protect coasts. That could be done in any of three ways — building undersea walls to direct warmer ocean water away from the continental ice sheets, propping the ice shelves up with artificial islands, or draining the water beneath the ice which acts as a lubricant to speed them on the way to the sea. Artificial islands are already being used extensively in the Middle East. In Engabreen, Norway, tunnels beneath the ice provide enough water to run a hydroelectric plant 24 hours a day.

So how much is this going to cost? Wolovick admits making his suggestions a reality will be costly. But compared to the damage rising ocean levels could do to coastal populations — which he suggests could amount to as much as $50 trillion a year — the projects he proposes will be a bargain. The sea walls and flood defenses needed to fend off rising seas would cost tens of billions of dollars a year to build and maintain.

None of the projects Wolovick proposes will be a permanent solution. At best they will slow down global warming enough to buy humanity some time to come to its senses about addressing climate change. The fate of the ice sheets will depend ultimately on how quickly the world brings down fossil fuel emissions.

We Must Reduce Carbon Emissions

“Glacial geoengineering is not a substitute for emissions reductions,” Wolovick says.

“Glacial geoengineering will not be able to save the ice sheets in the long run if the climate continues to warm. [T]here are two possible routes that glacial geoengineering could take. On the one hand, it could be a stopgap solution meant to preserve the ice sheets until the climate cools enough that they are once again viable on their own. On the other hand, it could be a managed collapse meant to keep the rate of sea level rise down while slowly letting the ice sheet waste away. If we emit too much carbon into the atmosphere, then the only viable long term usage of glacial geoengineering would be to orchestrate a managed collapse.”

Despite all the evidence that the planet is getting warmer, Wolovick is an optimist. “Climate change is not an inevitable apocalypse. Climate change is a set of solvable problems,” he says. “Climate change is a challenge that our species can and will rise to meet.” The Comment that Wolovick helped write is filled with more details about how his ideas could be implemented. It is clearly written and highly readable. Recommended reading for all clean techies.


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About the Author

Steve writes about the interface between technology and sustainability from his home in Rhode Island and anywhere else the Singularity may take him. His muse is Charles Kuralt -- "I see the road ahead is turning. I wonder what's around the bend?" You can follow him on Google + and on Twitter.



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