http://www.zmescience.com/wp-content/uploads/2007/11/eco-footprint-image_sm.jpgI was recently asked about carbon footprints, and how we can reduce our environmental impact to a genuinely sustainable level. The problem being, whatever you enter into the calculators, and whatever actions you take, it’s still practically impossible to get your footprint to the level of one planet living. And one planet living has to be the ultimate goal, rather than a 20% reduction by 2012, as the government is currently aiming for.

We want to live in a way that isn’t borrowing from the future, but we know we’ve done all we can on the lightbulb and thermostat front. We’ve thought long and hard about where we go on holiday, and how we get to work. We seem to have done all we can, and still our carbon footprint is higher than it should be.

Part of the problem is that carbon footprints are notoriously difficult to evaluate. There’s no official standard, and different calculators include or exclude different things. Most talk about housing and transport, and usually household appliances, but don’t talk about background activities such as food and leisure activities, or shopping habits. Some work from rough estimates, others demand accurate figures taken from your gas bills. And then there’s the presentation of the questions, and how many choices you get and how precise you can be.

So, it being a rainy day, I’ve tried out a number of different carbon calculators. In order of good news to bad news, here’s how many tonnes of CO2 I am responsible for every year.

Google: 1.54
ActonCo2: 1.72
MSN: 1.8
BP: 2
Carbonfootprint.com
: 2.97
Clevel: 3
Bestfootforward: 5.3
WWF: 9.31

In other words, nobody has any idea how much carbon I am responsible for.

  • The first few figures are ridiculous. As a human being I hit 0.5 tonnes per year just by being alive and breathing.
  • Google asked me if I had a car and I said no, and it seems to be assuming that I therefore do not travel at all.
  • BP asked me if I took baths or showers, which is barely relevant in CO2 terms. They didn’t ask if I filled the kettle every time, or how often I ran the washing machine, which other calculators wanted to know.
  • C-level didn’t have an option for anyone who doesn’t own a car, and I jammed their system. I had to lie and say I did, but travelled zero miles in it.
  • C-level also asked me to choose between ‘buy new when needed, moderate shopper, buy most food from supermarkets’ and ‘buy secondhand, grow own food, buy local’. What if you buy secondhand and local, and don’t grow your own food?
  • MSN counted my travel and utility bills, and didn’t ask about anything else.
  • The WWF asked me how many hours I spent on the bus every year, rather than how many miles I travelled. With London traffic that’s a pretty horrendous figure, so that would explain the large figure there. But is it accurate? Who knows?
  • Cows may contribute up to 16% of global co2 emissions, but only WWF asked if I ate meat.
  • None of the calculators deal with consumption in any serious way, but our shopping habits are responsible for a huge percentage of our carbon footprint. Some had one question, usually something simple like ‘how many bags of shopping do you buy in a week?’ Most ignored it altogether.
  • I’ve got a sneaking suspicion some of these are calculating individual footprint, and others household, but aren’t making it clear. Or they’re not sure whether they’re assessing carbon footprint or wider environmental impact.

So, let’s take a guess and say I’ve got a rounded 4 tonnes to my name. Is that good or bad? Clevel say the UK average is 10 tonnes a year, so I’m doing pretty well. MSN say the UK average is 5. Google says it’s 3.5-6.9. I’ve also found figures saying 11 and 12.

The Climate Outreach and Information Network has undertaken a more scientific comparison of carbon calculators. Their winner is Resurgence. It’s probably the most thorough, and also the least flashy. Unfortunately it’ll be too specific for many users, and I didn’t have the information to make it work myself. They also recommend Clevel and MSN.

In conclusion, we need to keep some perspective on carbon footprinting - it’s only a useful tool, not a strict science. And besides, we’re working out individual numbers here, often for the purpose of buying offsets. This is useful, but the most significant impacts on our footprint are often things that are bigger than we are. We need to operate at the level of community, take on systems and institutions, and change our culture, before we’ll really be getting anywhere. There’s the danger that in making sure we’ve done our bit (and some websites are offering a one-off carbon offset for life!) we’re actually ducking out of the real challenge.

But, we do still need to do what we can as individuals. This post is long enough, so I’ll deal with what I think are the biggest priorities in a future post.

If anyone can recommend a better calculator, by the way, please let me know.