Too good to be true--can we fix global warming?

n the most recent issue of the Economist, there is an article under the Science and Technology section on a possible solution to global warming using the Earth’s natural transport system to get rid of caron dioxide. Dr. Alfred Wong from the University of California, LA,

reckons the problem is not so much that CO2 is being thrown away, but that it is not being thrown far enough. According to his calculations, a little helping hand would turn the Earth’s magnetic field into a conveyor belt that would vent the gas into outer space, whence it would never return.

The conveyor belt is situated in Fairbanks, Alaska at the High Power Auroral Stimulation facility, one of two locations where the Earth’s magnetic shield opens up to outer space.

Auroras. . . pleasingly testify to a stream of particles from the sun that gets through and hits the atmosphere. These particles bring with them many gigawatts of power that Dr Wong wants to harness to reduce the concentration of greenhouse gases in the atmosphere.

His idea starts with the fact that CO2 molecules like to team up with loose electrons, to form CO2 ions. A few percent of the CO2 molecules in the air manage to find such electrons. As a result they become negatively charged…all over the Earth there is a constant vertical electrical field. The surface and the atmosphere form a giant battery…This field tends to make negatively charged ions, such as those of CO2, drift upward. At first this happens slowly…But after a few days they arrive at an altitude, about 125km up, which is so rarefied that an ion can move freely about. This is when the last stage of their one-way trip into space begins: sailing along the magnetic field of the Earth.

High in the polar regions, the lines of magnetic force point almost straight upwards. When a charged particle is in a magnetic field, it tends to travel along that field’s lines of force, spiralling as it goes. In the case of a CO2 ion at an altitude of 125km, it spirals round 17 times a second.

However, as it travels upwards, it experiences a weakening field. It must then make fewer turns per second, in obedience to a law of physics called the conservation of magnetic moment…And because it cannot just shed its energy of movement, it is forced to travel faster and faster in the direction of the field. The eventual result is that it is ejected into space.

We shall have to wait and see if Dr. Wong’s confidence in his scheme proves to be fruitful.