Respectable statistics show that the number of humans on earth now exceeds 7 billion, an almost unimaginable number. I often think of this when faced with the decision on whether to throw away or recycle a metal bottle top.

Suppose 7 billion people recycle one bottle top each. From the internet I discover that a tin or aluminium bottle top may weigh around 2g. So that’s 7 billion * 2g = 14,000,000,000g = 14,000 metric tonnes of metal. That’s a hell of a lot of metal! If done every day for a year that makes around 5 million tonnes.

Other statistics show that the annual global production of metals is around 131 million tonnes (steel), 57 million (aluminium), under a million (tin). So that one bottle top (times 7 billion times 365) corresponds to a significant percentage of global production.

Of course, not everyone on the planet has a western standard of living, and not everyone in the West uses a disposable bottle top daily, so this is not a realistic sum. I don’t even know if it’s practical to recycle all bottle tops. (It seems that individual small metal caps may not get automatically recycled by current household recycling systems; they may need to be collected in a larger container.)

This trivial example points the way to much more serious questions. Consider air travel or sports that involve killing animals, or eating lots of meat… If everyone aspires a Western style of living there is just no way the earth can support the realisation of this.

Maybe we just need to start thinking ‘7 billion’ in all key personal and political decisions. But maybe that’s just too hard. In the end nature will take its course…

Featured number was at time of writing,
from the website http://www.worldometers.info/world-population/