The rebound effect
Energy efficiency improvements often do not deliver reductions in energy use. For example, when a householder installs better insulation, the energy savings are sometimes much less than would have been predicted. Sometimes this is because the insulation was badly fitted, but it is often because the householder runs the heating at a higher temperature when the house is better insulated. This is called the ‘rebound’ effect: when it becomes cheaper or more effective to use energy, people use more of it.
The many studies into this effect have produced a wide variety of different estimates for the size of this effect. Most cluster between 10 and 30%. This means that energy efficiency improvements generally result in a large net benefit. But these studies only capture the direct effect on consumers and businesses. A study from the UK’s Energy Research Centre shows that the economy-wide impact may be much larger. For example, lower heating bills may mean that householders are rich enough to take more flights. At an even higher level of abstraction, better economy-wide energy efficiency (through, say, improvements in steel-making technologies) may encourage more rapid economic growth, which in turn raises energy use.
Some economists think that the economy-wide rebound from energy efficiency gains is very large – perhaps over 100%. A figure over 100% suggests that total energy consumption rises after energy efficiency improvements. The tentatively stated view of a new report by the UK Energy Research Centre is that the true number is somewhat lower than this and may be around 50%, although it could be a great deal higher.
Government projections for the impact of energy saving measures never take the rebound effect into account. Policy-makers trying to reduce global emissions need to adjust their thinking to reflect the much lower than expected efficacy of energy saving programmes.
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Organic matter, such as agricultural waste, heated in the absence of oxygen splits into two types of material: a charcoal (biochar), and hydrocarbon gases and liquids. When added to soils, the charcoal can provide a powerful fertiliser. The hydrocarbons can be burnt, either to generate electricity or to power an internal combustion engine.
Biochar is exciting growing attention around the world. Charcoal’s ability to improve soils can sometimes be spectacular. But more importantly from a climate change perspective, charcoal is almost pure carbon and is strangely stable in soils. It seems to persist for centuries. Charcoal can therefore offer substantial opportunities for long-term sequestration of carbon. The valuable fuels from the biogases and liquids are also carbon-neutral since they contain CO2 previously captured during photosynthesis. As a third major benefit, soils fertilised with charcoal seem to need less artificial fertiliser, thus saving fossil fuels. Fewer applications of fertiliser would reduce the level of emissions of nitrous oxide, a particularly dangerous greenhouse gas.
Post-industrial countries like the UK import an increasing fraction of their manufactured goods from China. The carbon emissions from the Chinese factories making these goods are not included in the UK’s totals. How much greater would the UK’s emissions be if we included the impact of goods manufactured in China?
The Goodall household is well-trained. Compostable products get put on the compost heap. Plastic bottles end up in the recycling bin. Where should Innocent’s new smoothie bottles made from bio-degradable corn starch go? Surprisingly, the answer is into landfill.
Innocent, the company with one of the purest brands in the UK, has made a mistake. For the last year it has used a new material called PLA for one of its ranges of drinks. It admitted last week that it would cease to use this bio-plastic later this year. But on its website it was still making some surprising claims. It says that the bottles made from this bio-plastic break down in garden compost heaps. They will not. PLA needs to be heated for several days to temperatures far greater than those in a domestic compost bin before it begins to rot. The bottles would break down in a commercial composter, but very few local authorities operate one of these plants. Innocent’s ethical consumers are going to find a large number of plastic bottles at the bottom of their compost heap next spring.
The Peak Oil question is beginning to become a central part of the daily debate on energy matters. On one side is an increasing number of independent scientists and oil engineers who note that world oil production is barely rising. Existing fields are running down and new reserves are found rarely. On the other side of the debate are the major institutions of the global oil industry. The International Energy Agency sees world oil supply rising from about 88 million barrels a day now to about 116 million barrels in 2030.
Video conferencing has been around for a surprisingly long time. AT&T ran the first call in 1927. Since then, pundits have been consistently predicting that video conferencing was just about to take off. They have been wrong for eighty years. Why should we believe the techno-optimists now?
A recent Henley Centre survey suggested that 86% of people were eager to buy goods with less packaging, up 20% in the last two years. Nothing arouses as much spontaneous anger among British householders as the ‘over-packaging’ of foods. Recent newspaper headlines conveyed righteous indignation about the policies of UK retailers, in particular the failure to make all packaging recyclable.
The newspapers completely missed the point. Three issues need to be emphasised:
Only 1% of imported organic food comes by air. But the Soil Association says that air freight ‘can generate 177 times’ the CO2 of shipping. Air transport is necessary for some fruit and delicate vegetables which provide a vital source of income in some poor countries.
The Association was caught in a dilemma. It didn’t want to give its valuable imprimatur to foods that caused climate damage but neither did it want to impoverish poor tropical communities.
It is adventurous of E.ON to decide to invest in tidal stream generator farm. The announcement in the last few days confirmed that the company intended to put a tidal plant off the coast of Wales in a partnership with Lunar Energy.
The Severn barrage scheme (see
Nobody expects a Severn barrage to be built soon. But government opinion appears to be swinging in favour of the idea. The independent Sustainable Development Commission has just brought out a report that broadly supports a barrage. Though the environmental costs will be high, it says that mitigation measures will counterbalance some of the damage.
We now also have a better feel for the economics of the scheme or, more correctly, for both of the two main options for blocking the Severn. The bigger scheme blocks the estuary between Cardiff and Weston-super-Mare. It will cost about £15bn and deliver just under 5% of the UK’s electricity. The smaller – just downstream of the Severn bridges – will cost a tenth as much, or £1.5bn, but will provide a sixth as much power as the bigger project.
Bjørn Lomborg, a professor at Copenhagen Business School, is the most formidable critic of those who think that cutting climate-changing gases is the most important problem the world faces. He made his name with 'The Skeptical Environmentalist' and his new book continues his drive to get the world to see global warming as just one of the world's important problems.
Lomborg believes climate change is happening, and that mankind’s activities are responsible. But he tells that we shouldn’t do much about global warming because the costs are very high and the benefits low and far-off. Like most books written by partisans in this impassioned debate, much of what he says can be questioned.
The Pre-Budget review in early October disappointed green activists. Environmental measures formed a small fraction of the government’s initiatives. It doesn’t look as though Alistair Darling sees climate change as one of the priorities of this administration. But there were two important commitments: a revision to Air Passenger Duty (APD) and (via BERR) a competition to run a commercial-scale carbon capture project.
The APD proposal attracted most attention. The government intends to change the duty so that it is levied on aircraft movements and not on individual travellers. Commentators, and the two main opposition parties, have long suggested that this would be a sensible change. Carbon Commentary disagrees. The proposed revision cannot be implemented without infringing international treaties on the taxation of air travel. The chancellor’s proposed consultation will eventually conclude that APD should remain substantially as it is now.
BT’s green credentials are well established. It is the largest commercial buyer of renewable electricity in the UK, emphasises the importance of carbon reduction across the organisation, and pushes voice and video conferencing at an unconvinced customer base. In any international ranking, BT’s sustainability measures get high marks.
But BT has the same problem as many other organisations: its server farms are growing in number and size. The increased power consumption in its data centres explains why the organisation’s electricity demand is growing. Eventually, its brand image will suffer as critics suggest that its public stance on green issues is not matched by its internal behaviour.
Many agricultural crops can be turned into fuels. Diesel substitutes can be made from the oil in seeds. The sugars in cereals and tubers can be fermented into ethanol.
At first examination, biofuels look as though they might significantly reduce carbon emissions. An agricultural crop takes carbon from the air through the photosynthesis process. When the harvest is processed, and the output used as a fuel, the carbon returns to the atmosphere. Proponents sometimes said that agricultural crops make ‘carbon-neutral’ fuels.
The Advertising Standards Authority is struggling to hold the line on the advertising of environmental benefits. In June, the Authority put out a series of instructions trying to impose clearer conditions on advertisers. But it continues to have to adjudicate on a series of difficult decisions. Last week saw a wind power developer taken to task for over-estimating the carbon savings from turbines. The Authority had to decide which type of power station would produce less power as a result of a new wind farm – coal or gas. It took advice from the National Grid and proceeded to tick npower off, even though the power company was following rules previously set down by the ASA itself.
In at least one other country, the advertising regulator has thrown in the towel and told some advertisers simply to stop advertising green claims. Reuters reports that Norway’s Consumer Ombudsman has told car advertisers that ‘We ask that…phrases such as “environmentally friendly”, “green”, “clean”, “environmental car”, “natural” or similar descriptions not be used in marketing cars.’
Many companies selling to UK families have a strong sense that consumer demands are shifting rapidly. M&S recently talked to Carbon Commentary about its perceptions of changes in attitudes and behaviour. This article compares its results with those of a survey by the Henley Centre in summer 2007.
During the last year or so, the percentage of 'green zealots' in M&S research has risen from 3-4% to nearer 8%. Henley also sees a figure of 8% for the two greenest groups 'principled pioneers' and 'vocal activists'. A further 31% (Henley Centre) or 30-35% (M&S) are actively concerned and want to adjust their behaviour. There has also been a big growth in this group in the last year.