As I see it, the biggest risk associated with climate change is the shut down of the thermohaline conveyor belt. This happened 8,200 years ago and 12,700 years ago as we've talked about here, and radically altered the earth's climate for a hundred year and thousand year period respectively.
The Atlantic's circulation pattern is altered when ice in Canada and Greenland melts and lots of cold, fresh water flows into the Atlantic. This shuts down the pump, that drives the conveyor.
This would make a huge hunk of Europe uninhabitably cold and could lead to droughts in sub-tropical parts of the world. Leaving many in developing countries with chronic food shortages and millions of French in a desperate Crepe shortage. Panic ensues.
While I was shoveling and spreading salt the other day, I had a wacky idea. I was worried that the salt was going to get into the sewers and flow into the Charles.
But then I wondered: what if we somehow diffused a substance like Halite in the melt runoff at the mouth of streams in Canada and Greenland? Increase the water's salinity and temperature through a mild exothermic reaction. Could this help to avoid shutting down the conveyor belt?
This could only work if a significant portion of the runoff flowed together to form streams and rivers into the ocean, and not just a million drip, drip, drips across the coast. But I imagine that the runoff does form streams.
There would definately be environmental concerns. The local marine eco-system at the base of the rivers and streams would get screwed. But if it would work, it might be worth it.
We don't need to do this today of course, but if we monitor the situation, and start to get worried in the future, we can install diffusers at the mouth of streams and rivers spewing out a benign chemical to raise salinity and temperature.
Is this idea dumb... probably. But, I think its worth considering.