5 Aug 2010

The Mackay Calculator

Well, we now know what Prof David Mackay has been up to at DECC. Rather than fiendishly devising infuriating incentives, he has been beavering away on a spreadsheet the size of Hyde Park, attempting to put some maths into the carbon reduction targets. It’s called the 2050 Calculator and it’s here. It’s open source and Mackay asks for interested parties to download it and play with it, and even tinker with the source code to try and improve it. Whether it will be the sort of thing that attracts the Linux set, I have my doubts, but there’s no harm in asking.

The Guardian launched its own carbon calculator back in April. It makes an interesting compare and contrast. The Guardian’s version is far simpler, and the graphics are much better. It works on a series of sliders which give instant feedback on the effects of your choices. In contrast, the DECC calculator is clunky: instead of slider controls, you get multiple choice boxes. Click on one of these and the graphic changes, but not instantly, and usually the change is so small that you can’t actually take in the effect your action has had. Maybe this is deliberate, maybe it isn’t, but it’s disconcerting at best.

The briefs are different too. The Guardian’s calculator is altogether a darker shade of green, looking at issues like low carbon diets and consumer consumption. The DECC calculator is more complex, giving a total of 134 choices, but they are more narrowly focused on pure energy issues.

The depth of the work going into this calculator is revealed in a supporting document called 2050 Pathways Analysis, a 246 page epic which takes off from where Sustainability Without Hot Air left off. Here you can read the assumptions that Mackay has made, and in many ways this is more interesting than simply playing with the calculator (which pales very rapidly - I doubt it will keep many people interested for more than a few minutes).

What stands out is that some actions have huge consequences - a massive switch to nuclear power, carbon capture and storage - whilst most have very limited impact, second-order effects at best. Our great debates about heat pumps, biomass and the rights and wrongs of the Code for Sustainable Homes look pretty trivial in the face of all this.

And there are assumptions in this Calculator which presumably have to be taken as political givens, when in fact they should also be questioned. For instance, Mackay seems to be happy to accept that over the 40 year period the population grows by 25%, the number of households by 50% and GDP by almost 200%. I’ve always felt that these growth assumptions are ludicrous in the face of the problems we are up against, and that we should be aiming for a stable population, a stable number of households and a commitment to smart (i.e. low carbon) growth. Ok, it’s just my opinion, but why shouldn’t they be presented as options for limiting energy demand? Why are they off limits?

What would be nice to see is a simple executive summary which explains what all the assumptions are, and then ranks the importance of the actions we can take. I know its complicated. Everything is interconnected. Nothing is quite that straightforward. But it doesn’t get easier to understand by presenting it as a Calculator.



  1. A couple of tips for using this 2050 calculator that might help: all the settings are stored in the page URL, so you can bookmark them. You can also open multiple tabs and flip between settings pages to compare the subtle differences more easily.

  2. GDP growth of almost 200% is less than 2% per year by my calculations - sounds conservative.
    To prevent population growth we would probably need to ban immigration. Can't see that happening, and I can't see greens arguing for it (given that most greens (eg minus Zac Goldsmith, 'lol') are mostly just lefties with a new plan of attack).

  3. That's a very British viewpoint.. Not every country plans for an ever increasing population. Have a look at a blog I wrote a couple of years back on this very subject.


    By 2050, Germany will apparently be empty. I don't think that makes Angela Merkel a looney green leftie, or a closet racist.

  4. Dave HoworthAugust 05, 2010

    "It’s open source and Mackay asks for interested parties to download it and play with it, and even tinker with the source code to try and improve it. Whether it will be the sort of thing that attracts the Linux set"

    Well it would be interesting but it's written in a format that requires using a proprietary Microsoft program to run it, so no, the Linux set can't use it.

    Despite the government's much vaunted support for open-source initiatives, DECC has failed repeatedly to provide any such support.

    I'd post a comment at Mackay's blog, but he requires me to create another useless ID to do so. Perhaps that's why nobody else has posted any comments there either?

  5. It's true, at least on my run-of-the-mill Linux system. Open Office, which is usually quite good at reading MS Office docs, hung twice trying to load the spreadsheet.

    Perhaps they are not all that keen on other people's input after all.

  6. I actually think population is the biggest concern this planet has, and the effects of a growing population on our resources and our carbon emissions could be disasterous. Control population for the world and then any carbon reduction targets would be much easier.

  7. "GDP growth of almost 200% is less than 2% per year by my calculations - sounds conservative" yes, and completely out of the question. All indicators are that the planet is already well into extra time, in its capacity to reprocess the results present economic activity, let alone a tripling within 40yrs (if that's what 200% growth means) or even a doubling (if that's what it means). See http://www.amazon.co.uk/Prosperity-without-Growth-Economics-Finite/dp/1844078949/ref=sr_1_2?ie=UTF8&s=books&qid=1281435414&sr=8-2 (but that book is actually needlessly pessimistic).