Archive for February, 2010

How to measure your personal carbon expenditure

February 23rd, 2010

When every kilogramme of carbon we produce contributes to climate change, then we each have a responsibility to minimize our own personal carbon emissions. While lots of media campaigns concentrate on the narrow field of just what we buy—stopping using plastic bags, buying certain produce—the majority of our personal carbon emissions actually comes from heating and lighting, cooking our meals, and travelling from place to place.

But it’s very hard to make moral choices when you just don’t have information about what impact you’re having. To do that you need to be able to measure your carbon emissions. And to do that, without being some sort of atmospheric scientist, you need to have a tool which translates meter readings and car odometers into relative carbon measures. There’s lots of sites out there that can take vague data about your lifestyle—how many people are in your house, how often you use the washing machine—and give you a similarly vague estimate of your “carbon footprint”. But what about if, say, you turn your heating up from 18C to 21C over Christmas? What does that mean in terms of the carbon your home emits?

Enter The Carbon Account, one of a few carbon calculators out there. It will collate your meter readings—gas and electricity—and work out how much carbon that represents based on how green your service providers are (so completely renewable electricity provision means zero carbon emissions.) It also translates car mileage, using available efficiency data for different car models, into fuel usage and hence emissions. Slightly more alarmingly, it takes any plane flight emissions and multiplies them by a “radiative forcing” factor—the estimate of the extra damage caused by emitting CO2 in the upper atmosphere—to compare them more fairly with your home and car’s emissions. You’ll find rather quickly that any plane flights you take will dwarf all but the most life-changing efforts you’d make elsewhere.

What does all this mean? Well, first and foremost, there’s a principle of “behavioural accountability” which suggests that anything measured will be almost automatically be reduced, if that’s what you want it to do. It’s a funny effect, but you’ll find your behaviour changes just from seeing those graphs going past. If you’re keeping a closer eye on your carbon emissions, and you spot the big blue lump that came from your road trip round Europe last year, then you’ll think twice about doing it next year. Conversely, if you’ve insulated your loft and you see your gas usage drop dramatically, you know a little bit more about the moral good of that decision, not just the financial good.

It also means that, while in the natural, ignorance-is-bliss course of things nobody can really excuse any plane flights anywhere, that if you can demonstrate that your carbon emissions are below the accepted per-capita global allowance by e.g. 0.2 tonnes for five years, then that means you can then justify a 1-tonne-equivalent plane flight. Carbon becomes a moral commodity, which you can save up over time and then spend on luxuries like aeroplane travel (if you really, really have to.)

In the interests of full disclosure, let’s start with a graph of my carbon usage from last year.

graph of carbon usage

What does this tell us? Well, let’s start by explaining the structure of the graph. On the vertical axis is kilogrammes of CO2 per month: that means that if the graph is at “200” for a whole month, then I’ve used 200kg of CO2. On the horizontal axis is of course months of the year. The three colours indicate the fractions of usage owing to electricity (mustardy green), car usage (blue) and gas (claret). Along the top are notes: when you submit a reading, you can also add a note to it, to remind you of anything important you did at that point (e.g. insulated the loft, or sold the car!)

The detail available is actually immense, and if you’re serious about cutting your carbon, for whatever reason, you can get a lot of information out of a graph like this. For example:

  1. We moved house in the latter half of 2009, from a leaky 3-storey cottage to a terraced house. You can see the effect on both electricity and gas readings if you compare either side of October. We didn’t turn the central heating on in the new place straight away either: hence the sharp dip.
  2. The car was used a lot in December 2008/January 2009 as I didn’t cycle, hence the wedge of blue on the left. The little note marks the point where I started cycling regularly and frequently again.
  3. We used the car to help us travel back and forth, redecorating, before we left and locked up the old property in October. There’s a large lump of blue around the summer that indicates that, with a note at the end of the period to indicate when we switched everything off at the old place.
  4. Our electricity usage is not seasonal: the height of the mustard-yellow component is almost constant at the old house, then it changes to another constant value at the new one. That means that e.g. increased lightbulb or oven use in winter baking has far less effect than the fridge being on all year round.
  5. Our gas usage is definitely seasonal: see how much the claret graph varies. It’s also the greatest single component of our carbon emissions, so if we want to do anything to improve the house’s efficiency rating then we have to look at draughts, insulation, a new boiler etc.

Since taking this image I’ve added more data to my Carbon Account, including our increased power usage over winter, and a car journey to see family at Christmas. Our house move’s effect on gas usage looks considerably less impressive since the cold snap, but that in itself gives us pointers about what we can do next.

The Carbon Account isn’t perfect: none of the tools out there are. It doesn’t include rail, bus or ferry journeys; it doesn’t account for well-tuned, ecodriven cars using far less fuel than badly maintained ones; and it doesn’t measure carbon from the produce you buy, or the carbon that the state—NHS, governmental departments, city maintenance—emits on your per-capita behalf. But it can help to change your lifestyle, and hopefully change your life, for the better.

If you’re interested in trying out the Carbon Account, you can do so straight away: register on the site now. It’ll ask you for a few details so it can calculate an initial estimate but that’s it. Alternatively, come and say hello this weekend at the Fair Trade Market. I’ll be on the Sustainable Witney stall from 10.30 till at least lunchtime, laptop in hand, to help demonstrate the Carbon Account.

(Even fuller disclosure: I work for the company which originally built The Carbon Account. But this isn’t really a plug, as we handed over ongoing development and support to a government-supported organization. I just happen to still use it loads.)

Edible Gardens

February 15th, 2010

The History of Bees

February 14th, 2010

It was standing room only in the Witney Museum on 3rd February 2010 as members of the Wychwood Project gathered to hear Shaun Morris, beekeeper, biologist and former director of Oxford Scientific Films tell “The History of Bees.”

Morris left his photographic kit at home. Instead he chose the role of story-teller and had the audience captured for ninety minutes with a vivid account of the evolution of the honey bee.

The bee split off from the other hymenoptera and “went soft”, choosing a diet of plants (as opposed to hunting) to support ecology by collecting pollen to feed its grub and make honey. Evolutionary pressure led these originally solitary bees to become social; males have half the number of chromosomes as females. Workers help the mother raise the next generation creating a social unit.

The structured unit in the hive has a queen which lives on average five years as opposed to her wild who lives twelve months. In the hive she has her coterie of attendants, drones waiting for the opportunity to mate and workers maintaining the hive environment. The queen never leaves the hive so is dependent on the hive being kept well maintained and at the correct temperature all year round. This requires sufficient stores of water and sugar to provide air-conditioning or central heating created by the wing movements. Honey which is nectar and water processed in the stomach is disgorged and is available as stores. The remainder tends to be judiciously raided by the bee keeper during the summer months.

The worker bee has a short life span; five weeks. During weeks two and three it lives close to the hive entrance, measuring up the world and taking training flights. Its final two weeks are spent foraging.

Bees have a distinct language. The waggle dance directs them precisely in direction and distance to the species even indicating the quality of nectar. They compete with other colonies so their scouts are careful to find the most economical routes and efficient food sources. As bees have evolved, flowers and their patterning have likewise.

As bees are part of a colony which may make 150lb of honey per season it seems reasonable that the sting as a form of defence has re-emerged in its evolution. It was a relief to learn there is one occasion when we are fairly safe from attack, which is when they are in a swarm; planning to start their next colony.

As we broke up for tea, Morris let us each sample his visual aid – an 80 year old pot of dark honey. Bee miles? Twice round the circumference of the world!

Rae Cather

iSlab? iSlate? No – iPad!

February 5th, 2010

After years of speculation Apple finally unveiled their Tablet computer last week. If you own one of their phones your instant reaction was probably “A Dom Jolly iPhone!” And if you follow Star Trek it’ll be immediately recognisable from the captain’s ready room.

My first taste of Apple was with the iPhone, which is what I’m tapping this into at the moment on the train. I’ve since moved over to a MacBook too (that’s a laptop) and it really is a different experience – no more phaffing around with firewalls and anti-virus software, no more waiting endlessly for it to boot up,and even better, no more hanging around for it to shut down – it just works. Anyway, enough of the adverts, what’s this got to do with sustainability?

Well, they’ve sold an awful lot of iPhones (75 million if I remember correctly) and it looks like they might sell a good deal more iPads – I’m sure to be getting one. So what about all the lithium batteries? What about all the shipping from their manufacturing base in China?

To put things into perspective, the battery for an electric car will weigh at least a hundred times more than a complete iPad. And a short browse on their website shows they recycle their products as well as measuring the emissions for the lifetime of their products.

The Environmental Report for the iPad isn’t up yet, but this is the one for the iPhone.

So what do we think? Ecologically sound? Or corporate greenwash?