Steel can, left, aluminium can, right.

Steel (left), Aluminium (right)

I am a student of litter. I use my jogging time to see what people are tossing out, and I also pick up a few cans on each run. So it quickly became obvious to me that 2007’s litter was not the same as 2006’s. Suddenly Coke cans were not rusting. They were shining up at me. They were made of aluminium.

I phoned Coca-Cola to find out what had happened, and they explained that they were temporarily importing Coke from Singapore and elsewhere because of the local shortage of carbon dioxide. (How ironic that as we swelter from the greenhouse effect, South Africa should have a shortage of carbon dioxide!)

I mention this not because I am appalled at the thought of the energy required to get a can of Coke from Singapore to Johannesburg. (Though I am.) It’s too late to do anything about that. What matters now is that these are aluminium cans instead of the usual steel cans used in South Africa. And in the hierarchy of recyclables, aluminium is king. Whether you recycle or toss away a polystyrene cup matters little in the scheme of things. Throwing away an aluminium can is a mortal sin.

Making aluminium from bauxite requires ghastly amounts of electricity, which is why you will find aluminium smelters in places like Mozambique that have none of the raw materials for aluminium and no market for aluminium but do have lots of cheap energy. For every ton of aluminium produced from coal-based electricity, 13 tons of carbon dioxide are spewed into the air.

That’s the downside.

The upside is that aluminium recycles beautifully, saving 95 percent of the energy originally used to make it. Recycling an aluminium can saves the energy equivalent of enough petrol to fill half of that can. It’s enough energy to burn a 100 watt globe for 4 hours.

For this reason, aluminium cans have a high value to recyclers. The men who wander the streets in search of scrap metal might not want your steel cans, but they will gladly take aluminium. If you can’t get the cans to a recycling depot, leave them to the side in a separate bag on your garbage collection day. They can also be taken to any Johannesburg Pikitup refuse site or Collect-A-Can depot. (Don’t expect any money for your cans. Collect-A-Can requires a very large quantity before they pay for aluminium.)

There are several ways to tell if your can is aluminium. Look at the bottom: steel cans are dull; aluminium shines. Hold a fridge magnet against the can. If it doesn’t stick, it’s aluminium. And if the can feels light and makes a rattling noise when you crumple it, it’s aluminium. Some imported beers, Red Bull and V energy drinks are all packaged in aluminium.

Since all of these are imported drinks, they are inherently wasteful. If you must drink them, picking up a littered aluminium can and recycling it is a great way to atone for your sins.