Ideas pop up constantly during our daily life – Chicken for dinner, a new pair of shoes for a party, or perhaps planting a new ornamental cherry in the back garden. But then, occasionally, there are inconceivably big and bold ideas that come up. Climate Change evokes some of these “Big Ideas.” Dutch scientists recently proposed damming off the entire North Sea and Baltic Sea to prevent rising sea levels from affecting Europe. Now that’s a very bold engineering idea.
The project requires a total of 395 miles of construction split between two dams. The longest of these stretches 295 miles from the northern tip of Scotland to Bergen in Norway. The route forms the northern barrier, and it also extends over 400 feet below sea level in some places. The southern barrier stretches 100 miles between South England and France.
This project far surpasses anything previously attempted. Currently, the largest dam in the world is in South Korea. It extends 30 miles in length and reached water depths of slightly over 100 feet. The estimated sand needed for the concrete North Sea dams exceeds the entire annual sand budget of the world – 51 billion tons.
No solution is perfect, and the audacious North Sea dams face significant ecological challenges. The interruption of tidal cycles would destroy the North Sea food chain. Also, the salinity of the enclosed area would gradually decrease when freshwater from coastal rivers mixes with the former open ocean waters. Perhaps the engineering plan needs input from ecologists on how to establish a new ecosystem in the extraordinary lake the dams create.
Less sunlight
Another bold engineering idea for handling global warming is to rocket a massive array of solar screens into interplanetary space. The screens reflect sunlight away from the planet, thus reducing the amount of solar radiation reaching the earth’s surface. Less sunlight then translates to less heat and less warming.
Some industries get excited about this approach since it doesn’t require that we reduce greenhouse emissions to control global warming. We can keep on burning those fossil fuels. When more greenhouse gasses clog up the atmosphere, we just shoot some more screens into space. Evidently, if we block about 2% of the sunlight from the earth, global warming will stop under current conditions.
There is a point in interplanetary space called the L1 Lagrange point. Its fame is that a satellite screen placed in that bit of space always stays directly between the earth and the sun, thus providing a constant damper on solar radiation reaching the planet’s surface.
It goes without saying that no one understands the full ramifications of cutting the earth off from 2 percent of its sunlight. There will be consequences; we just don’t know what they are. Perhaps plant growth will slow down, cutting the sequestration capacity of earth’s forests.
Big, bold engineering projects are fascinating, but they often only address a single element in a complex web of relationships. Their purpose is adaptation to specific aspects of climate change. Often, they do not examine the full impact of the project on the earth’s ecosystems. Perhaps that part of the analysis is coming. We don’t yet fully know what role geoengineering will have, if any, in climate change mitigation and adaptation.
Sources
Scientist suggests damming the North Sea to protect Europe from climate change (Dezeen) – https://www.dezeen.com/2020/02/14/nothern-european-enclosure-dam-climate-change/ Also:
Ask Ethan: Can We Build A Sun Screen To Combat Global Climate Change? (By Ethan Siegle; Forbes) – https://www.forbes.com/sites/startswithabang/2018/05/26/ask-ethan-can-we-build-a-sun-screen-to-combat-global-climate-change/#5245365f1f00 Also:
Feature Image: LightSail 2 with deployed solar sail (By The Planetary Society) (Modified) – https://commons.wikimedia.org/wiki/File:LightSail_2_with_deployed_solar_sail.png – This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. – https://creativecommons.org/licenses/by-sa/3.0/deed.en