When geoengineering goes wrong

Paul Raven @ 26-03-2009

Barcelona sunsetWhile it’s probably a bit too soon to go rushing into geoengineering projects in an attempt to readjust the earth’s runaway climate, discussing the ideas thoroughly is of great benefit – principally because it gives people a chance to pick holes in the plans and think of potential downsides before we do something irreversible.

Exhibit A: seeding the atmosphere with dust to increase the amount of sunlight reflected away into space might actually be shooting ourselves in our renewable foot, so to speak:

While such atmospheric modifications would only be expected to deflect about 3 percent of the sunlight incident on the earth, Murphy has found that solar energy collectors would face a reduction of up to one-fifth of the usable energy that they collect presently. Even though 97 percent of the sun’s light will make it through the Earth’s modified stratosphere, much of it will be scattered, making the light diffuse. Diffuse light cannot be focused in the same manner that direct light can be, which lessens its usability in most optical systems. Almost all projects that harness solar energy require a large portion direct sunlight that can be focused and concentrated on a cell of some kind.

So: reduce the bad effects of sunlight, and you’ll reduce the useful ones as well. Best relegate that plan to the back-burner… at least until someone finally develops a usable fusion system.

On a similar note, it looks like iron-dumping in the ocean is off the menu at least for us. For a certain type of shrimp, however, it’s very much on the menu:

The iron triggered a bloom of phytoplankton, which doubled their biomass within two weeks by taking in carbon dioxide from the seawater. Dead bloom particles were then expected to sink to the ocean bed, dragging carbon along with them.

Instead, the bloom attracted a swarm of hungry copepods. The tiny crustaceans graze on phytoplankton, which keeps the carbon in the food chain and prevents it from being stored in the ocean sink.

Back to the drawing board. Thank goodness for thinking ahead, eh? [image by papalars]

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One Response to “When geoengineering goes wrong”

  1. Jay says:

    I actually wrote a chemistry paper about iron fertilization. The marine biologists attached to the LOHAFEX experiment suggested iron fertilization could be used to stimulate the base of the food chain in the open ocean, supporting fisheries and whale populations.