A Little Light Romance

First published by Superior Sentinel February 2007 under the title "Why Bother?"

When I was growing up we had an 'ice box'. About once a week in the summer my Dad drove five miles to the 'ice house' and bought a block of ice. The ice had been cut from the harbour during the winter months and stored in a barn-like structure under mounds of sawdust. The block was placed in the top insulated part of the box, the lower part had a door and shelves inside for our food stuffs that needed to be kept cool.  In the years that my father did commercial fishing he built his own ice house and stored his own ice.

We just used H2O in its solid state and nobody got hurt.

Nowadays there are almost 64 million domestic fridges and freezers made each year on this earth and demand in the so-called developing countries is double what the industrial nations buy.  These are added to the already millions that exist.  Up until the mid 90's the cooling substance for these refrigerators and freezers was the ozone depleting substance CFC-12.  (Greenpeace says the new refrigerant, hydrocarbon R600a, isobutane, is cheaper, uses a smaller quantity and can be easily adapted to present equipment.)  The insulation in the refrigerators/freezers was CFC-11, also an ozone depleting substance.

Now, as long as those CFCs are in the appliance they won't harm the ozone layer that is floating around at about sixteen to thirty kilometers above the earth. The harm comes when that old fridge/freezer of yours goes Ka-putt and you get a new one.  What do you do with your old fridge/freezer? ... Long pause to think...

I know what a lot of you did. You drove out to a Bush Road and dumped it. You may have even patted yourself on the back because you removed the door so no one could crawl in and suffocate.  Let's look at what happens as the CFC-12 leaks out of your abandoned appliance.

CFCs is short for Chlorofluorocarbons, a mixture of chlorine, fluorine and carbon atoms.  Organochlorines get lumped into this lot too.  These gases are unreactive as they drift upward through the atmosphere.  In other words, they mind their own business for four or five years and don't even get washed out with the rain.  When the CFCs reach reach the stratosphere things literally heat up. The CFC molecules absorb the high energy electromagnetic radiation of UV light sufficient to break up the molecule and release a chlorine radical.  Anyone who was around in the 1960's knows what trouble a radical can be.

The Chlorine radical falls in love with the oxygen triplets named ozone.  One runs off with him and the other two are left to fend for themselves.  They fall afoul of the Electromagnetic radiation high energy UV light wave and get separated. In its lonely state the oxygen atom latches onto the Chlorine monoxide molecule creating a reaction that regenerates a chlorine radical while the two oxygen go off together and meet another lonely oxygen atom and become ozone again. And so on and so forth...for a hundred and twenty years - that is how long CFC-12, dichlorodifluoromethane, can remain in the atmosphere.  This process is called the chlorine catalytic cycle (CCC).

On the global scale, the annual emission of CFC-12 was at its peak in 1987 with 492,900 metric tonnes.  At this time aerosol production was still going on in countries that hadn't banned its use.  Oddly enough 1987 was the year the Montreal Protocol prescribed limits on emissions of fully halogenated CFCs. Since then the world has dropped about three hundred thousand metric tonnes off from all sources. That sill leaves many millions of tonnes of CFC-12 cycling through the ozone in the stratosphere or does it?

The high atmosphere is dominated by nitrogen with a good mix of oxygen in the single atom state with a scattering of ozone.  The National Academies of Sciences found a second set of chlorine reactions that actually tied it up in stable compounds of chlorine nitrate ( from chlorine monoxide and nitrogen dioxide) and hydrochloric acid (from the chlorine radical and methane). Hydrochloric acid can precipitate and come out of the atmosphere. Both compounds could get zapped by electromagnetic radiation and get back in the action.  However, it seems that for the most part they can sequester chlorine monoxide and the chlorine radical for a long time and keep the CCC inactive and give the ozone a break.

Meanwhile, back in our small corner of the earth, the refrigerators in the bush turned to garbage magnets.
 By 2010 most had been removed by persons unknown.
Thank you