Archive for November, 2009

Planet Dimming

Friday, November 13th, 2009

Many articles and at least one fine book have been published in the past couple of months, intent on providing our leaders who meet in Copenhagen next month with the information, insights, and possible solutions they need to come to some useful agreements.

As Tim Flannery emphasizes in his essay/book ‘Now or Never’, we have passed the ‘tipping point’ in the concentration of atmospheric CO2, and are approaching the level of ‘point of no return’. Time is running out, and the planet of ‘point of no return’ is going to be extremely harsh on the well being of humans.

So now it is time for desperate measures. Climate engineers, also called geoengineers, have made a number of proposals to cool the planet. These include adding sulfur dioxide to the atmosphere, spraying up a fine mist of sea water to brighten the clouds, and sending into orbit huge numbers of small reflective objects – the intent of all three is to prevent some of the sunlight from reaching the Eath’s surface.

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They don’t deal with the route cause, but they would buy us time to reduce carbon dioxide levels. Despite our current reliance on fossil fuels, we could switch completely, and quickly, to wind, water and solar sources of renewable energy. In November’s Scientific American, Jacobson and Delucchi map out how it could be done.

As always, we just need the political will.

In any case, despite the bleak prospects of the effects of rapid climate change that we are all facing, there are solutions. My own preference among the planet cooling proposals is marine misting. We wouldn’t get the great sunsets that sulphur dioxide added to the atmosphere would give us, but we wouldn’t get the acid rain either. Orbiting millions of little mirrors comes with remarkable costs and risks.

But marine misting, or marine cloud brightening, challenging though it will be, is less risky, less costly, and if we unintentionally screw up other systems in the process, easier to stop. The engineers imagine robot ships, under their own renewable power, plying the seas and spraying a very fine mist of water droplets up 1000 feet. Of course the engineering challenges are considerable. Look at Scientific American Oct 21 (albedo-yachts-and-marine-clouds ) for more details. Now is the time for pilot projects.

Although time is surely running out, we clearly still have options. Our leaders have the ability to read, and think, and learn about the options. In Copenhagen, they also have an extraordinary opportunity to actually lead.