St. Lawrence Dam

The St. Lawrence Dam is a proposed 300 kilometer long dam connecting St. Lawrence Island in the Bering Sea to the mainland of Alaska and Siberia.

The plan was published by Dutch physical geographer Rolf Schuttenhelm in September 2008 [ [http://www.cleverclimate.org/climate/12/diomede_crossroads/ Diomede Crossroads – Saving the North Pole? Thoughts on plausibility - Clever Climate] ] with the purpose of starting an open scientific debate about possible costs, benefits and risks. According to Schuttenhelm the dam would improve ice conditions by decreasing both temperature and salinity in the Arctic, slowing down the present melting of sea ice and thawing of Arctic permafrost.

Climate effects

Possible benefits of the plan are the decrease of temperature in the Chukchi Sea by halting the northward inflow of relatively warm Pacific waters through the Bering Strait. As the proposed dam would be about 300 kilometers south of the narrowest point, the actual strait, it would also decrease salinity in the Arctic by restricting all fluvial input of the Alaskan river Yukon to the Arctic Ocean.

Geo-engineering

Proposed geo-engineering approaches with the purpose of controlling or slowing down global warming may focus on either the increase of carbon uptake (on land or in oceans) or the increase of the radiative balance of the Earth, for instance by cloud seeding or the so called space sunshade.

The St. Lawrence Dam however has another focus: preventing or slowing down two positive climate feedbacks within the Artic system – one being the albedo effect, the other Arctic methane release from thawing permafrost. When geo-engineering approaches effectively lower greenhouse gas emissions, they could enforce present mitigation efforts.

Railroad connection

Since the late nineteenth century several plans have been published for a bridge over the Bering Strait as part of the Cosmopolitan Railway. In 2007 Russian authorities announced plans to construct a Bering Strait tunnel [ [http://www.timesonline.co.uk/tol/news/world/europe/article3646415.ece Bridge-building Vladimir Putin wants tunnel to US - Times Online] ] .

Building the St. Lawrence Dam would allow a direct railroad connection over land between Eurasia and America. If the dam would be build first, it would make the proposed tunnel redundant.

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