This has been an issue in developed nations for a while, and a variety of strategies have emerged to deal with them. The » EU has led the way,
and 100% of tyres are processed in some way in continental Europe. Some
countries levy a tax on tyres and then the government takes charge of
them. Most EU countries have made the tyre companies responsible for
taking them back at the end of their lives. Britain has a free market
for end of use tyres, which manages to deal with 95% of them.
Elsewhere, the growth in car ownership is often outstripping
legislation to deal with waste tyres. Billions of them are now
stockpiled around the world. So what do we do with them all?
The easiest and worst thing to do with ELTs is to put them in landfill. Here’s a » photo essay from Kuwait,
where tyres are piled up in their millions and then buried in the sand.
We used to do this in Britain too, but it’s now illegal under EU waste
directives. The trouble with tyres in landfill is that they leach toxins
into soil and water. In tropical countries they fill with water and
become a paradise for breeding mosquitoes, making them a serious health
risk. Even if you’re tempted to ignore both of these issues – because
you’re dumping them in the desert, say – they’re also dangerous. Tyre
dumps are a fire risk, and burning tyres are notoriously hard to deal
with. A valley full of 10 million tyres caught fire near Knighton in
Wales in 1989. It took months to put the fire out, and then it
smouldered until 2004 – an impressive 15 years.
So landfill is a bad idea. Besides, dumping them loses the materials
and energy they contain. But since they burn, maybe that gives us an
obvious solution – incinerate them to generate electricity, or for heat
in steelworks or cement kilns. This is known as ‘energy recovery’, and
that is the fate of about half of Europe’s tyres. They’re quite a good
fuel, as it happens. They are as energy-dense as coal, and they don’t
produce nitrous oxides. Where they displace coal, tyres could arguably
be considered a greener option. But they do produce other pollutants,
some of which are a health risk. The exact environmental impact of
energy recovery depends on how they are burned and what sort of
scrubbing technologies are used, but we’re talking about the lesser of
two evils here. It’s better than landfill, but we’re only capturing some
of the energy in tyres, and the materials are still lost.
There are a number of ways to reuse the materials in tyres, and since
the EU banned sending tyres to landfill, a whole lot of research and
development has gone into it. Lots of new businesses have emerged that
treat end of life tyres as a resource. One of the more common is the
rubberised surfaces used in playgrounds and running tracks. There are
only so many of these in the world though. With mountains of ELTs to get
through, we need large scale uses – like road building. Ground up tyres
are now regularly used in asphalt, and there are several advantages.
Roads with rubber in them have better grip, and they’re 50% quieter.
They last three times longer than normal tarmac, and don’t need as much
Another potential customer is the railways. Recycled rubber pads can
be fitted under railway or tram tracks to reduce noise and vibration.
Switzerland has been doing this since the 70s. An Italian company called
» Greenrail goes one
further and has developed a sleeper made from ELTs. This reduces demand
for concrete and ballast, and they run quieter too. 35 tonnes of used
tyres would go into each kilometer of track using Greenrail sleepers.
In the hierarchy of waste strategies, recycling come after reuse, and
many tyres are already retread and sold on. Retreading has been
possible for a while, and the technology to do it is better than ever.
Unfortunately, public perception of » remanufacturing
is a problem. 90% of buses and trucks have retread tyres. Taxis and
commercial fleets use them. The general public are more sceptical.
That’s something that needs to change, as keeping tyres in circulation
for longer is one of the simplest ways to reduce the waste mountain.
Regulation varies around the world, and nobody wants to drive on
inferior tyres, but in Britain retreads have to meet exactly the same
standards as new tyres. They should be more common.
Even with all these techniques in play, we have an underlying
sustainability problem. Natural rubber is still a key ingredient in
tyres, and that means we’re still relying on forests to supply our raw
materials. As more people drive, the demand for natural rubber is
increasing, and the risk to forests and biodiversity increases too. In
the long term, we’re going to need more radical alternatives. And that’s
going to have to be another post.