Radical reductions

We need to cut fossil fuel use in the developed world by 90% to stop dangerous climate change, argues George Monbiot.

Heat: How we can stop the planet burning

• George Monbiot

Penguin UK: 2006. 304 pp. £17.99

Credit: PENGUIN BOOKS UK

With the recent release of the reports from the Intergovernmental Panel on Climate Change, the science of climate change has become firmer: warming of the climate system is 'unequivocal', and most of the temperature increase since the mid-twentieth century is 'very likely' owing to the rise in greenhouse gases. Climate sensitivity — the response of the system to a doubling of CO₂ — is now "likely to be in the range 2 to 4.5°C with a best estimate of about 3°C". Yet despite the formal coming-into-force of the Kyoto Protocol, the question of what to actually do about climate change in practice remains open. In Heat: How we can stop the planet burning, Monbiot lays out a clear proposition of what we need to do: cut fossil fuel use by about 90% in the developed world. Most of what follows is an attempt to make this practical, or at least to present options that might be believable, without ending up as "a very poor third world country".

Even so, he is forced to propose changes in society that would cause major upheavals. There is confusion at the heart of this, in that the emissions scenarios that cause us to worry about future warming assume as their basis a world that gets much richer, even allowing for damages from climate change. We could argue (I would) that this is richer in a merely material sense. Nonetheless, people show a considerable appetite for increasing affluence and it is hard to see how large-scale policy changes can be founded against such opposition. To convert such opposition, Monbiot refuses to consider a cost-benefit analysis: to him, it is a moral issue, to be decided on how much we value people and places as such, rather than figures in a ledger. In a popular book aimed at a mass audience this is an attractive approach — we can sweep away all the tedious, difficult and uncertain calculations and simply decide to do what is 'right'. In the real world, this is fraught with difficulties.

The bulk of Heat is a discussion of policies designed to reduce 'our' CO₂ emissions down to a sustainable level, to achieve a 'safe' level of climate change. Monbiot settles on 2°C above pre-industrial temperatures, or 1.4°C above present. As it happens, this is also the European Union's target. It is somewhat arbitrary, but for the purposes of exposition a target is needed, and the 2°C value is not unreasonable. However, what comes next is unreasonable: Monbiot decides that, if emissions are not lowered from today's values, we are likely to reach this temperature limit by about 2030. Even with increasing emissions, the IPCC mid range estimates are about 0.3°C per decade, giving us an extra 20 years before we hit Monbiot's limit. The confusion gets worse as Monbiot argues that we need a limit of 440 p.p.m.v. of CO₂ equivalent to limit temperature rises to 2°C, and that we are already at this 'safe CO₂' limit. He then neglects the extra CO₂ we will emit between now and 2030.

Credit: GETTY

Having decided on a 'safe' atmospheric CO₂ level not too much different from today's, Monbiot is nearly at his goal of finding a 'safe' level of emissions. Taking carbon cycle feedbacks into consideration, he then argues that the biosphere will absorb only 2.7 billion tonnes of carbon per year by 2030, down from 4 billion tonnes now, requiring a 60% cut in current global CO₂ emissions to achieve stability. Carbon cycle feedbacks are a source of great uncertainty; basing all your numbers on one paper from 2003 (C. D. Jones et al. Geophys. Res. Lett. 30, 1479 (2007)) neglects this; and yet in a popular exposition some collapsing of uncertainty is required. Finally, by deciding that equity requires everyone to have the same per capita limit, he arrives at a carbon ration of 0.33 tonnes per person per year, a cut of 90% for an average UK citizen. The last is a big step. By framing it in terms of equity, Monbiot avoids having to spend much effort justifying it, arguing that countries may not like it, but they cannot deny that it is even handed. This seems unlikely to provide a killer argument at international negotiations.

Given all the uncertainties involved, and big practical political obstacles to overcome, Heat is perhaps best regarded as a 'what if': if we did decide to cut greenhouse gas emissions by 90% within 30 years, what options are available to us to do this? This constitutes the main part of the book, and is a sweep through a large fraction of the carbon emissions of our society, as Monbiot boldly attempts to identify 90% savings in each area, starting with housing. This proves problematic: although new houses can be built to be far more energy efficient, the low turnover of housing stock precludes any great savings by 2030, and he concludes that only 30% cuts are possible. This leads to the energy supply industry, where the first option is carbon capture and storage (CCS): continuing to burn fossil fuels as normal, but burying the resultant CO₂ perhaps in old oil or gas reservoirs, with the advantage of helping extract a little more fuel in the process. Many environmentalists dislike CCS, as for them the whole point is to use less energy, but Monbiot surprised me by judging it favourably. He concludes that CCS could supply half our electricity by 2030, which seems optimistic as the International Energy Agency judges it will only start to become usable by 2030. Nuclear power he considers with trepidation and dismisses. The prescriptions for these sectors are relatively uncontroversial, requiring few changes to behaviour. His prescriptions for transport are more radical: a complete re-vamp with a switch to hypercars, lower speeds and standards of performance, car-free shopping and a major expansion of the bus network. Even this is mild in comparison to the fate of most airplane journeys, which cannot be done within the CO₂ budget he imposes.

How does the book fare overall? Monbiot manages, with a degree of optimism, to find probably technologically feasible solutions to most of our CO₂ emissions. Where he is far less convincing — especially measured against the recent past and current situation — is in making these changes seem politically feasible.

William Connolley is a climate modeller at the British Antarctic Survey, Cambridge, UK. wmc@bas.ac.uk