Emissions: Where do you draw the line?

How and when are climate changing emissions justified, asks Leo Hickman

guardian.co.uk, Tuesday 16 December 2008 14.35 GMT

Didcot coal-fired power station. Photograph: Charles O'Rear/Corbis
IBM's World Community Grid is currently attracting quite a lot of attention online after it was announced earlier this month that this vast network of public-spirited computer users - 418,972 users to date, offering 1,143,230 machines - would pool their collective computing power for a brand new project called the Clean Energy Project.
Harvard University's department of chemistry and chemical biology has set itself a mission to discover organic materials that might create an efficient, low-cost solar cell. But it needs some help. Left to its own devices, the department estimates it might take 22 years to trawl through all the various combinations of organic materials in its search for a eureka moment.
But with the help of more than a million computers around the world, most of which have already helped to speed up projects researching treatments for various cancers, dengue fever and HIV/Aids, it hopes this can be reduced to just two years.
What's more, none of the users offering up their machines need do anything other than - à la the SETI@Home Project - download some software that sits on their machine harmlessly doing some calculations whilst they get on and play World of Warcraft.
There's a slight catch, though: the computer can't slip into its energy-saving idle mode whilst performing these calculations which means there will be an extra energy burden, albeit pretty small, for the user to consider. Most people would surely agree, though, that this is a worthy use of energy.
It throws up an interesting dilemma: how and when do you draw the line between emissions being justified and unjustified. There's a big difference between using a barrel of oil to heat a hospital compared to, say, using it to ferry rock stars around the world in a jet. But what if those rock stars are being flown to a refugee camp to help divert the global media's attention to the plight of the people in that camp?
There's been lots spoken about the recent climate change talks and emission target pledges and, like it or not, we seem destined to live in a world whereby the richest countries can pay poorer, less developed countries to do their emissions dieting on their behalf.
Supporters of this system say that a cap-and-trade, market-based solution is the only realistic way a reduction in global emissions will ever be achieved. Carrots are always better than sticks, they say. But in such a world, it will be rare for a distinction to be made between why emissions were created in the first place.
There will be a market-determined price to pay for emitting a tonne of carbon dioxide into the atmosphere, but no one will be asking why you emitted it as long as you pay the going rate.
But is it beyond our collective wit to also judge our energy use against a set of criteria that gives extra weighting to our essential and most worthy needs?
Surely, as fossil fuel supplies dwindle, as more and more people are predicting, this question will become ever more pressing? How ever you look at it, it invariably leads you down the path of some form of rationing, otherwise the richest will just buy up the right to burn all the remaining fuel.
At some point, our most essential services will need to be given priority when it comes to dishing out the remaining fossil fuels equitably. In theory, this will start to price out "non-essential" uses of such fuels.
But who is going to draw that line between essential and non-essential use? What, for example, would you place into the "essential" trolley? Two thousand miles' worth of petro-fuelled driving a year? Enough energy to heat your living room to 18C during winter?
Given that we each lead very different lives, should each of us have a "free" minimum allowance for such essentials?