Marcy Wheeler alerts me to the huge economic consequences of the drought of 2012 as it relates to the Mississippi River. Since those canny Ron Paul supporters shut down the NAFTA Superhighway, the might Mississippi remains the key shipping highway connecting north and south in America. And because of the drought, the water level has dropped so significantly, that barges have to delay their passage.

Coast Guard spokesman Ryan Tippets told The Associated Press on Monday that the stretch of river near Greenville, Miss., has been closed intermittently since Aug. 11, when a vessel ran aground.

Tippets says that the area is currently being surveyed for dredging and that a Coast Guard boat is currently replacing eight navigation markers. He says 40 northbound vessels and 57 southbound vessels are currently stranded and waiting for passage.

The Army Corps of Engineers is working to solve the problem by dredging 60,000 cubic yards of sediment per day. But this still has not led to full passage on the waterway. The barges must drop their loads significantly, if they can pass at all.

This has an enormous economic impact. About 500 million tons of cargo passes on the Mississippi every year, including 60% of all US grain and goods totaling $180 billion in value. If it no longer works as a reliable waterway, that severely diminishes productivity and stops the delivery of goods to market. And there’s more:

Besides impacting the 500 million tons of cargo that travels up and down the river annually, the low volume of water coming down the river is putting local water supplies at risk. The corps is building a dam of sediment to prevent a wedge of salt water creeping up the Mississippi from entering into local water supplies drawn from the river. The difficulties stemming from reduced river levels highlights how climate change will have impacts far beyond warmer temperatures. In fact, we’ve shown how states will bear a high economic cost, and low-lying states, like Mississippi, are already seeing the high costs of climate change.

Someone should do a study on how often reports of the costs of the solutions to climate change are highlighted in the media, relative to the costs of inaction. This is just one slightly obscure example of the latter.