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So, let's talk green: Plastic trees to the rescue

Physicist Klaus Lackner estimates that 10 million plastic trees could drop Co2 concentrations by 0.5 parts-per-million per year.

While it is not 'breaking news', it certainly is hot news! Planet earth is getting warmer because of human activity. We are producing huge quantities of greenhouse gases (GHG's) which is making the atmospheric layer thicker, resulting in more infrared waves from the sun getting trapped, instead of getting reflected into space. These GHG's, mainly carbon dioxide (Co2), are emitted when we burn fossil fuels, mainly to generate electricity.

James Hansen, Former Director at the NASA Goddard Institute for Space Studies, estimates that the total warming trapped on planet earth because of continuous GHG emissions over the last 80 to 90 years is equal to 400,000 Hiroshima bombs exploding every day for a whole year! When we look at summer temperatures from the 1950's, we will notice that the extreme temperature events that used to cover 0.1% of the Earth now cover 10%. It is no wonder then that we are all feeling the heat getting worse every summer.

Today we treat the atmosphere as a free open sewer. Smoke stacks from industries, exhaust pipes of automobiles, all spew pollution, and all the while Co2 accumulates, warming the world. While there are multiple attempts to reduce emissions by moving to renewable energy, scientists are also working on removing the existing Co2, that is already in the atmosphere. Many possibilities exits to remove Co2 from the atmosphere, including helping soils trap carbon, burying Co2 at sea, etc. But a scientist at the Arizona State University, has now pioneered a new technology using plastic.

Physicist Klaus Lackner at Arizona State University and his colleagues have discovered a resin, that is normally used to purify water, that seems to be hungry for Co2, and has shown capability to suck Co2 out of the atmosphere. Lackner inserts a strip of plastic impregnated with particles of this resin, and the Co2 levels inside a test tank begin a steady march down.

A small prototype of an artificial plastic tree that would use the resin to cleanse the sky sits on top of a building on Arizona State campus in Phoenix. The plastic tree doesn't look very aesthetic, but its thin strips of beige, wavy plastic stacked one atop another in a clear box hidden from the desert sun by a piece of plywood covered in a black cloth, seems to be doing its job of sucking our Co2 from the atmosphere. Lackner estimates that 10 million plastic trees could drop Co2 concentrations by 0.5 parts-per-million per year, putting the world on track to remove all the Co2 it has added over the course of the next few centuries. But to counteract the 40 billion metric tons of Co2 dumped each year would require more like 100 million plastic trees.

Those 100 million plastic trees would also consume a lot of electricity and water, among other things, and that's if the resin works as well as hoped. The American Physical Society suggests capturing Co2 from the air might cost roughly $600 per metric ton, which makes an expensive proposition, if used to pull 1.5 trillion metric tons of GHG's out of the atmosphere to reduce concentrations by 0.01 percent. Remember that this deployment, if it works, would just be just the first step of picking up the Co2, because now, all this must be disposed somewhere.

The best bet as of now, seems to be to bury it back underground just like all those fossil fuels. Or more energy can be applied to all that captured Co2 to transform it back into fuels like oil or ethanol-an opportunity to endlessly reuse and recycle the carbon if a cheap, abundant, clean energy source can be found and used.

For now, I am sending blessings to scientists like Lackner, who may just be able to solve the increasingly alarming climate change crisis that the planet is facing.

( Source : Deccan Chronicle. )
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