Rising trends in atmospheric CO2

CO2 output is accelerating, the ocean and land sinks are getting less effective at absorbing it. So the rate of growth of carbon dioxide in the atmosphere is increasing. (Canadell, Le Quéré, and others, 'Contributions to accelerating atmospheric CO2 growth from economic activity, carbon intensity, and efficiency of natural sinks', Proceedings of the National Academy of Sciences, 25 October 2007; URL: http://tinyurl.com/yqew8o [accessed 27 October 2007].)

The pre-industrial CO2 concentration in the atmosphere was about 280 parts per million. It was 381ppm in 2006. The growth rate between 2000 and 2006 was 1.93ppm, a significant increase on growth rates in earlier periods. Many policy-makers see it as vital to keep below concentrations of about 400ppm of CO2. The increase in the rate of rise of CO2 makes the achievement of this target more difficult.

Increases in the amount of CO2 in the atmosphere reflect the volume of global emissions and the effectiveness of the oceans and land mass in absorbing greenhouse gases. This paper contains evidence both that emissions growth is speeding up and that the greenhouse gas sinks are capturing less CO2.

The growth rate in emissions between 2000 and 2006 was 3.3% a year compared to 1.3% in the 1990s (please see the article on Chinese exports in this issue of Carbon Commentary for corroboration of this finding). This increase reflects fast economic growth, particularly in China and India and a worrying increase in the amount of CO2 produced per unit of global output. It cannot be stressed enough that this second cause of emissions growth is unexpected. We thought we were going to see energy use fall in relation to economic output.

By contrast, models have predicted a decline in the effectiveness of ocean CO2 ‘sinks’. This paper shows that we can have a strong suspicion (but not near certainty) that this process has started. The authors point to increasing wind speeds in the Southern Ocean as a primary cause. This turbulence ‘ventilates’ the carbon dioxide contained in the surface of the sea. Droughts in mid-latitude regions have contributed to the decreased efficiency of land absorption.

The paper concludes that – with large margins of error – economic growth generated 65% of the increase in atmospheric CO2; the decrease in the efficiency of the sinks generated another 18% and caused a rise in the carbon output required to generate a dollar of world GDP.

The authors summarise by saying that their results ‘characterize a carbon cycle that is generating stronger-than-expected and sooner-than-expected climate forcing’.

The Soil Association and air freight

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 carried out a detailed and thoughtful consultation with stakeholders. It seems a model of its kind. The consultation produced a consensus that air freight was only acceptable if the products were farmed in a way that brought development to the local community. In essence the Association is saying that only ‘Fairtrade’ products will be able to carry its valuable label. It won’t be enough just to meet the ordinary standards for organic agriculture.

Peter Melchett, the policy director of the Association, said that the ‘results of our very widespread consultation show that most people in the North and the South say that they only support air freight if it delivers real environmental and social benefits. The linking of organic and ethical or Fairtrade standards does that’.

The Soil Association will now move to ratify this decision, which went against central government advice, at least as expressed in a recent speech by a minister.

In the same press release it also announced a move to involve the Carbon Trust in providing a ‘footprint’ for organic foods (please see the article on organic food and carbon emissions in Carbon Commentary Newsletter #1). It said it would move towards carbon labelling of organic foods (please see the article on Tesco and Wal-Mart in Carbon Commentary Newsletter #2 for reasons why we think this is a mistake).

In a slightly surprising move, it also announced that it would seek to ‘actively encourage people to eat less meat’. Since beef cultivation is an important source of emissions, this makes good sense, but the Association is taking a risk by suggesting people should change their diet.

It also intends to review whether heated glasshouses are appropriate recipients of organic labels. This last point is well overdue. The carbon footprint of a food from a Dutch heated glasshouse is likely to be far greater than an air-freighted equivalent grown in the tropics.

BT’s wind farm proposals

BT uses over half of 1% of the UK’s electricity and is the single largest purchaser of green electricity in the UK. It buys over 10% of the country’s total supply of renewable electricity. It now seeks to develop wind turbines on some of its own sites. It intends to invest in about 120 2MW turbines to produce about a quarter of its own electricity or between 0.1 and 0.2% of the UK’s total need. This is an impressively large plan. The cost is about £250m. The financial return will depend on how much of the electricity replaces power BT would have bought from other suppliers and how much is ‘exported’. Assuming very little is used by BT itself, the return will be approximately £50m a year, yielding a return of about 20% on the initial investment. These figures assume that BT gets a yield of about 28% of the rated capacity of the turbines, which is about the UK average.

These figures depend entirely on finding sites. I think that BT may well have substantial difficulties finding as many 120 places where it can capture enough wind to average 28%. Perhaps more importantly, at many of those sites which do have enough wind, I think it will have problems getting connections to the local distribution network. Two of the three initial sites identified by BT are in the Scottish Islands. Although a typical 2MW turbine is not a huge generator to add to the local network, the islands have quite limited electricity needs. Scottish and Southern may not easily be able to add these turbines to their network.

When I asked BT whether it had approached the local distribution companies to check on this point, I was not given an affirmative answer. This raises the possibility that BT announced these plans before detailed consideration of whether its aspirations are technically feasible. So it may be a great idea to erest wind turbines, but it looks like it will be much more difficult than BT realises. Companies like Ecotricity have been developing wind turbines on industrial sites for years. Though planning permission is easier, there are still huge obstacles to overcome. BT needs Ecotricity's expertise immediately, but it will still struggle to meet its aspirations to grow its wind power capacity.

Is Kyoto dead?

(Gwyn Prins and Steve Rayner, ‘Time to ditch Kyoto’, Nature, 449, 973-5 (25 October 2007); URL: http://tinyurl.com/ys8flx [accessed 27 October 2007].) This short article has attracted attention around the world. Its thesis is that Kyoto is a dangerous distraction. It hasn’t worked, and its successor will not succeed either if it follows the same principles. Kyoto’s proponents have ignored its failures and exaggerated its effectiveness. It is worse than useless because it has stifled discussion of alternatives. However, their thesis is buttressed by two observations which are not accurate. They say that the International Energy Agency is predicting that world energy demand will double by 2030. It does not; it predicts a rise of just over 50%. Second, the paper states that the BP annual Statistical Review says that a likely global carbon price will not be high enough to induce major change. It does not; BP might think this, but its latest Statistical Review (referenced in the text) does not say this.

Like generals fighting the previous war, Kyoto’s originators based its design on the successful treaties on ozone depletion, acid rain and nuclear weapons. These problems were much more amenable to global regulation and the sharing of burdens was much more politically feasible. The authors of this paper suggest that policy makers should move away from treaties that try to put a cap on world emissions.

Prins and Rayner say that we need new techniques for getting a grip on the carbon problem. And, second, we need to work out how we need to adapt when severe climate changes arrive.

Their proposals for replacements for Kyoto are short and unspecific. In summary, they believe that the world needs ‘genuine’ emissions markets, not artificial constructs like Kyoto, and these markets must evolve gradually from local experiments. They mention approvingly some of the voluntary carbon markets that have grown up in the US. I think this faith in small informal markets is wholly misplaced. What possible reason would persuade a major polluter to participate?

The authors tell us we need to invest more in public R+D in clean technologies. In this they mirror Bjørn Lomborg (see the discussion of his book Cool It in Carbon Commentary Newsletter #3). They support messy public policies rather than ones that go for what they disparagingly describe as ‘elegant’ solutions. They see a role for measures such as mandatory technology standards (perhaps such as mile per gallon regulation on cars). The ideas they present are sketchy and unconvincing.

Many of us think that Kyoto and its successor are worth supporting as one of a package of measures. It is, after all, the only measure that we have currently got other than European ETS. Does it distract from finding other tools? I don’t see any evidence for the authors’ pessimism. Can it be merged with other global and local measures? Yes it can. No one pretends Kyoto is perfect, but because it tried to distribute the pain of emissions reduction reasonably fairly, it was a start. We can build on it; we need not destroy it.

E.ON and tidal stream technology

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 Carbon Commentary Newsletter #3) is a ‘tidal range’ scheme. The electricity is generated by damming the river at high tide and then letting the water flow out through turbines as the tide falls. Tidal stream technology captures the energy of the tide as it flows through constricted channels. The UK has many potential sites for tidal stream power stations, but the best locations are off the north coast of Scotland and around Alderney in the Channel Islands.

Why then has E.ON chosen Wales? Perhaps the company doesn’t want to test the technology in the toughest conditions. An attempt to use similar underwater turbines in New York’s East River has been frustrated by the breaking off of the tips of the turbine blades in the fast flowing tides. The UK’s offshore conditions will be far tougher. Or it might be that E.ON knows that it would be expensive or impossible to connect the turbines to the distribution grid in the locations of highest energy potential (see the news story in this section on BT’s plans for wind turbines in Orkney and Shetland). Previous rumours have suggested that the eventual site chosen will either be off the coast of Pembrokeshire or off Anglesey.

The recent report into the Severn barrage noted that there at least 24 different technologies for capturing tidal stream energy in the UK. The device promoted by Lunar Energy sits on the sea floor, is about 20m long and has a turbine diameter of about 12m. The blades sit within a case which focuses the tidal flow. As a Venturi device, the speed of the water flow within the case is greater than the flow outside, adding to the amount of energy that can be captured.

Is wave power economic? It is probably too early to say. The UK has excellent tidal streams around the country, but even this advantage may not be enough. Lunar Energy optimistically quotes figures of around 2.5p to 5p per kilowatt hour, which would make the technology extremely attractive, but these figures appear only to be based on some guesses made in the US. The Carbon Trust’s recent report suggested figures at least three times as much for the first implementations of tidal stream power plants. On the other hand, informal figures from the New York project have suggested figures close to the Lunar Energy estimates.

E.ON has been working with Lunar Energy for some time. It had been thought that the generator would not commit until after sea trials of the first Lunar device in Scotland next year. Last week’s announcement suggests that E.ON’s confidence in the technology and Lunar Energy is high.