Azara Blog: Carbon Footprinting: Industry, People, The Universe and Everything

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Date published: 2008/03/12

Adisa Azapagic (Professor of Sustainable Chemical Engineering at the University of Manchester) gave the fifth talk in the 6th Annual Lecture Series in Sustainable Development. Her title was the rather grandiose "Carbon Footprinting: Industry, People, The Universe and Everything".

The basic premise was that we should be calculating the carbon emissions (or to be more precise, CO2 equivalent emissions) of every good and service in the world. And her basic point was that to do so we need to calculate the carbon emissions due to the entire life cycle of a good or service. The Kyoto Treaty unfortunately only looks at the "direct" emissions (e.g. burning petrol to drive a car) and misses out the potentially large "indirect" emissions (e.g. refining oil to produce the petrol in the first place). Her analysis is perfectly valid and unfortunately it is one which is rarely made or even mentioned when discussing carbon emissions.

(The Kyoto Treaty is also flawed for other reasons, e.g. it looks at where the good or service is produced, not where it is consumed. Azapagic did not discuss this aspect.)

Now direct emissions are fairly easy to calculate, although even here there can be controversy. So, for example, for bus or train travel, how many passengers do you assume there are on average, since this has a proportional impact on the emissions per passenger mile. And focussing just on unit emissions, for example emissions per passenger mile, also misses out on the question of total miles. Taking a train from London to Cambridge to get to work might be more energy efficient per mile than taking a car from Histon to Cambridge to get to work, but taking the train is much worse in terms of total emissions because the journey is so much longer.

And indirect emissions are harder. For one thing, you have to look at the complete life cycle, from creation to transport to use to waste, and figure out how many emissions there are for each step. It is non-trivial and almost certainly open to vastly different conclusions. (One thing which Azapagic did not discuss is that there should be an open and free resource where people can deposit detailed analyses which can then be critically examined. As it is, an expert can say anything and nobody can really judge very well how good the analysis is, or even what the sensitivity is.)

And Azapagic ignored the indirect emissions due to labour. So, a railway needs employees to run the service and maintain the trains. These employees have to get to work (emissions), they have to eat to survive (emissions), they consume lots of products using their salary (emissions). These emissions ought to be counted against the emissions total for the train service. It never is. (For one thing, this is allegely even harder to account for. For another, it would make trains look not very efficient.)

When you look at the total life cycle emissions, you can come to some pretty interesting conclusions. Azapagic claims that wind, hydro, and concentrated solar power were the best (currently) and that nuclear was not far behind. Worse by some way were geothermal and biomass. But way worse still than any of those was ordinary solar power ("photo voltaics") as installed on houses up and down the country. (But still better by some way than gas or coal.)

Needless to say, the idea that solar power is not that great never makes it into the media. Of course the Azapagic analysis ought to be carefully examined to see whether the conclusions are safe. But it does show that life cycle analysis is worthwhile.

Azapagic pointed out that of course carbon emissions are only one very limited form of environmental degradation. There are plenty of other negative environmental impacts of producing goods and services. She mentioned two specifically, acidification and eutrophication. Here she claimed that ordinary solar power was in fact worse than gas. Well, needless to say, the media is totally focussed on carbon emissions, so ignore these other, important issues. At the end she was asked how you should weight the different factors, and she said there was no way, it was basically a political decision what to give what weight.

She gave some examples of emissions calculated using the total life cycle analysis. In transport she claimed that cars produced 180 gm / passenger km, buses 120, long-haul planes 120 and trains a fraction (circa 10 or 20) of this. As already pointed out, this ignores the indirect emissions due to labour, and is also assuming a certain passenger load and a certain base technology for each mode. So the sensitivity analysis is very important, and she did not have time to go into that.

The most amusing example was for tomatoes. She claimed that for British consumers, the total emissions for eating British-grown tomatoes is around 9.5 CO2 equivalent kg per kg of tomatoes. Supposedly the equivalent for Dutch-grown tomatoes is around 3.5 and for Spanish tomatoes (so even with all the transport included) is around 0.2. If you believe this analysis then you should not even consider buying British tomatoes (but presumably it is still ok to grow your own if you do it the old-fashioned way).

This was all good stuff, although it really needs detailed public debate by loads of experts to try and get these numbers confirmed (or not). Unfortunately at the end, in particular during the discussion period, Azapagic rather veered off script into some rather less sensible statements.

So she said she was against carbon sequestration because it was a "cleanup" technology rather than a "clean" technology, and it would just encourage people that "business as usual" was ok. Well, if you can reduce carbon in the atmosphere why should you care if it is done because people consume less (i.e. are poorer) or because we have found how to produce energy with less carbon or because we have found ways to remove carbon from the atmosphere? The ideal solution is "business as usual", in fact it is "business way beyond usual", since all the poor people of the world should have the same privileges as we do. Techno-fixes are by far and away the preferred option, if they can be achieved.

Unfortunately there are too many people who just want the world to consume less (i.e. to be poorer). Indeed, Azapagic mentioned the dreadful phrase "over consumption". And in the same context, when someone in the audience mentioned that there was a strong correlation between wealth and emissions, she jokingly said she was not wealthy. But of course she is wealthy, she's a professor. She might not be super-wealthy, like a banker, but she is wealthy. Certainly in comparison to the world average, but even in comparison to the UK average. And does she think that she herself "over consumes"? Well, she didn't address that question, but there are only two answers. Either "no", in which case why does she think that "over consumption" is a problem in the UK, when she is at the top end. Or "yes", in which case why doesn't she just ask her university to cut her pay. (And on top of salary, academics of course also enjoy lots of free travel all over the world, courtesy of the taxpayer. So the effective salary is higher than stated.)

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