March 8th, 2012

Reimagining greenhouse gases

by Ulrich Wiegel and Martin Steiner

 

Both solid waste and greenhouse gases are “wastes” in a broad sense. They are unwanted and potentially damaging by-products of the way that we live our lives in the 21st century. However, while solid waste impinges on our senses, greenhouse gases are imperceptible – and from this simple fact comes a huge difference in our attitudes.

In Western European countries with very good recycling systems (like Austria and Germany where we live), each person generates about 250kg of household and commercial waste per year, and a similar amount of separately collected recyclable material including paper, glass, and organic waste.  (In the UK, the volume is a little higher and the recycled proportion  a little lower).

But our emissions of greenhouse gases (measured in CO2-equivalents, to which the various greenhouse gases are converted relative to their impact) are around 10 tonnes, about 20 times greater. This vast amount of invisible, odourless waste is disposed of at virtually zero cost, even within the European carbon trading system. We simply dump the gaseous garbage into the “air ocean” on the bottom of which we live.

 

Exercise your imagination

Imagine you are following a car going 60kph, when you notice the driver is throwing an empty cigarette packet out of the window every two seconds. This continues for a minute, leaving 30 pieces of litter lying on the road, one piece every 33m – perhaps 150g of waste altogether. I suspect you’d feel pretty indignant. What if everybody behaved like this!

But at the same time, the car has left behind 150g of CO2 litter “on the road” via its exhaust. Does this annoy you to the same degree? Probably not: it barely exists in your perception. (And, after all, you were doing the same as you drove along behind…).

Recycling of solid waste is now so well developed that it saves more emissions (through substitution of raw materials) than are released during its collection and treatment. Three factors have driven improvements in this area:

  • the negative impacts of poor waste treatment are quite rapid (e.g. landfill sites causing groundwater pollution)
  • solid waste is tangible and smelly, keeping it in everyone’s minds and making dealing with it a political imperative
  • adopting environmentally friendly waste treatment yields relatively quick, local results

 

But with CO2 waste, damage occurs only following considerable delay, and is not connected to the source. The colourless, odourless gas does not impinge on our senses. And improved management yields benefits only in the longer term, and at a diffuse, global level. Can we be persuaded to make the costly changes needed to reduce the amount of this waste we produce?

 

If greenhouse gases were solid waste we would already have solved the problem

Let’s imagine – using the car example – that CO2 was a solid waste: of course it could not be dispersed on the road, but would be collected in a “dust box” inside the car. At each fuel stop for 50L of petrol, a dust box containing 130kg of “CO2-ash” would need to be emptied. Think of removing 130 bags of sugar from your car. Each petrol station would need large containers to collect it, and to capture all of our CO2 production our cities would require CO2-landfills twenty times larger than the ones we have for solid waste.

Picture by Lothar Lindner

 

In fact, if CO2 were a solid waste, disposal of waste from cars would never have become an issue. CO2 would have become a major problem 80–100 years ago, as the rapid expansion of industrialisation surrounded us with rising CO2-ash heaps. The notion of transporting a human body weighing around 100kg using a vehicle weighing more than 1,000 kg, resulting in energy loss of more than 90% would have been too obviously inefficient to ever take off. Still less would air travel – imagine if you had to carry away 5,000 kg of CO2-waste together with your luggage after each long-distance holiday!

Although the sheer scale of CO2 emissions is intimidating, our progress in dealing with solid waste in the last 30 years should give us hope. We have been able to develop highly successful solutions to the challenges of its management. This has been achieved through a combination of innovative technical measures and a society-wide “value change”. But we will only manage to repeat this with CO2 if we change the way we think about the intangible waste we produce every day. So when you stop to fill up your car, remember the 130kg of CO2 ash you need to empty from the dust box – perhaps it will make you think twice about the next car journey you take – particularly the one to the bottle bank.

 

A more detailed version of this article, entitled “The problem is not with waste, but with climate… – how perceptions influence behaviour”, is available in English and German.

 

 

Ulrich Wiegel and Martin Steiner

 

   

3 comments on “Reimagining greenhouse gases

  1. Martin Jonas on said:

    In my physics lesson I thought CO2 was so weak a gas it couldn’t possibly be responsible for ‘global warming’?

    It has only two absorption bands, both weak, and one wholly overlain by water vapour.

    What solid volumes of CO2 would an acre of forest absorb, by the way?

    I think there is some interesting research about the amazing benefits of increased CO2 levels on plant growth, done by a French University.

  2. Sam Taylor on said:

    Good point Mike! Putting it another way, a 1,600MW coal power station emits enough CO2 to fill two 240l bins for every household in the UK every day…better hope the compressors don’t break down!

  3. Mike Brown on said:

    Martin Steiner’s blog usefully makes us think about how much space CO2 takes up as a way of further understanding just how much of it we are all emitting. When you’re involved in one of the world’s most advanced Carbon Capture and Storage (CCS) projects (such that I and Eunomia colleagues have been working on since 2006) you actually have to work out where the captured CO2 can be permanently stored.

    The volumes involved are mind boggling. At normal temperature and pressure a tonne of CO2 occupies 500m3. A 1,600MW coal fired power station will emit around 8 million tonnes of CO2 per year. Once cooled in the atmosphere that’s 4 billion m3 a year – enough CO2 to fill Wembley stadium (1.14 million m3 according to Defra) 9 times over every single day!

    Whilst it is possible to compress CO2 500 times to around the density of water, it still requires around 8 million m3 of space to be found each year in which to store the CO2 for such a power station. Fortunately, such spaces occur naturally in depleted hydrocarbon reservoirs and in saline aquifers and the massive infrastructural challenge for CCS is to open up these geological storage sites and connect them to emitters.

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