Sunday, 24 July 2011

Volcanoes, Phytoplankton, & the Future of Geoengineering

From Flickr Creative Commons, some rights reserved

Keeping with the recent theme of climate change, today I will look at the potential of geoengineering to regulate climate change. If we cannot lower greenhouse gas emissions enough to mitigate climate change, we turn to Plan B— geoengineering. The idea of geoengineering stems from the 1991 eruption of Mount Pinatubo in the Philippines, which created a haze of sulphur particles that reflected sunlight away from earth and cooled the atmosphere by nearly a degree Fahrenheit. Today, I will show you the three most prominent geoengineering plans and how they could potentially save our climate.

1. Copy Mount Pinatubo

This plan is to emulate a volcanic eruption by injecting the atmosphere with sulphur, which reflects sunlight away from earth. Presently, there is no clear way to get the aerosols into the stratosphere. Potential solutions range from shooting sulphur-laden cannonballs into the atmosphere to having balloons carry the sulphur into the atmosphere. One significant problem with aerosol engineering is that the increased sulphur in the atmosphere would trigger acid rain.

2. Iron Seeding Oceans

The plan here is to pump iron into the sea to stimulate the growth of phytoplankton. Phytoplankton love iron, and are also very effective at pulling carbon out of the atmosphere during photosynthesis. The theory is that phytoplankton will pull substantial amounts of carbon from the atmosphere and then when they die after a couple of months, the carbon will fall harmlessly to the bottom of the ocean. The risk is in the uncertain affects on the ocean’s ecosystems from the increased iron and carbon. 

3. Whiten the Clouds

Here the plan is to whiten the tops of clouds so that they reflect more solar radiation. To do this, 1500 remotely driven, wind-powered boats would be used to spray seawater into the sky. The uncertainty here is how long the clouds would remain whitened.

Incredibly, these are three of the least imaginative plans. Other ideas include: shooting mirrors into space, building fake trees, and creating tubes to pump carbon into the depths of the ocean. Personally, I think whitening the clouds has the most potential as it requires far fewer resources and seems much simpler. I think that it’s important to remember that these are last-ditch efforts as all geoengineering plans have the potential to create their own environmental problems.  

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