Ten ways to start reducing your carbon footprint

If you buy just one new appliance in 2010, make it a really efficient fridge-freezer. The improvements in the energy use of the best fridge-freezers have been really impressive in the last few years. If you have an old refrigerator, it may be responsible for as much as a sixth of your electricity bill. A good new machine might use less than a half as much power, particularly if it is not too large. A second benefit is that by choosing to buy a really efficient refrigerator you will be sending a clear signal to the manufacturers that energy consumption matters. An impressive new web site – www.energytariff.co.uk – allows you to compare the electricity used by almost all the appliances currently in UK shops. You can make well-informed choices from your computer.

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Exceptional results from biochar experiment in Cameroon

Biochar Fund has reported extremely encouraging first results from its field trials in South West Cameroon. Working with small groups of subsistence farmers around the town of Kumba, the Fund set up and managed a large-scale experiment to assess whether maize (corn) yields were improved by the addition of biochar to the soil. The biochar was made from local agricultural wastes and tree thinnings. The data from the trials strongly suggests that biochar adds greatly to food production. Some areas showed yield improvements of more than 250% over the control plots. The areas dosed with biochar also showed substantially increased production of crop biomass, including roots, stalks, and leaves.

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No difference in the nutritional value of organic and conventionally produced food

A study commissioned by the UK Food Standards Agency concluded that: 'there is little, if any, nutritional difference between organic and conventionally produced food and that there is no evidence of additional health benefits from eating organic food.'

Yes and no. What the study actually shows is that organic food typically does have higher levels of important nutrients but the high degree of variability in the measured levels means that we cannot be 95% sure that these higher levels are not the outcome of chance. The Food Standards Agency and the report’s authors have misled people interested in this topic and should revise the summaries of their work.

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Biochar adds to food production in temperate climates

Biochar increases crop productivity in many tropical soils. The reasons probably include improved water retention, reduced leaching, and better availability of nutrients to plant roots. In temperate conditions, studies have been fewer in number and haven’t produced results that are as clear. A new study adds usefully to our knowledge.

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Republic of Maldives: a plan for carbon neutrality

The Maldives will be the first country to be overwhelmed by the effect of climate change. The republic is a collection of coral atolls with maximum heights of one or two metres above sea level. Climate change is increasing worldwide sea levels and the atolls will probably go underwater by the end of the century. The 300,000-400,000 people who live on the Maldives are not responsible for global warming. Their emissions per head (even including aviation fuels for incoming international tourism) are less than a seventh of typical European levels.

Many countries have set ambitious targets for the reduction of carbon emissions. The government of the Maldives seeks to encourage this trend by going one step further with a plan for near carbon neutrality within ten years.

This is an immensely challenging target. Chris Goodall (author of this blog) and Mark Lynas, the prize-winning climate change author, were asked to provide a short outline of how it might be achieved and what it might cost.

In the rest of this note, we show our calculations. We will be the first to acknowledge that this work is incomplete. Although it was tempting to conduct fieldwork in some of the most attractive island resorts, we did our analysis using publicly available information and with help from officials attached to the Maldives government.

Our work shows that near neutrality is possible, but expensive. It will take at least $1.1bn for this small island state. The Maldives imports almost all its fuels in the form of refined oil products. Rates of financial return to the investment therefore depend largely on the price of oil. If expectations of future oil prices exceed $100 a barrel, we judge that the plan is sufficiently attractive to be financeable by international institutions such as the World Bank.

Comments on this work will be very gratefully received.

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Why do global land use patterns matter so much?

George Monbiot rightly observes that the earth's resources of biomass are limited and cannot be simultaneously claimed for multiple uses: liquid biofuels, fuel for heating, biogas, and biochar. This presentation looks at the globe's land and biomass production to assess how much space can be given over to non-food uses and how much energy this can generate. This is one of the crucial questions facing the world: how much energy can we use from biomass before this affects the ability of the world to provide enough food for nearly 7bn people, rising to at least 9bn by 2050?

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Jatropha

Alok Jha of the Guardian wrote about Air New Zealand’s trial of jet fuel based on jatropha berries. This note looks at the percentage of the world’s land area that would have to be devoted to the crop in order to provide for the total needs of aviation, an industry that uses about 5% of the world’s oil.

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Are biofuels responsible for the sharp spikes in food costs?

The world has decided that much of the blame for the rising cost of foods can be ascribed to the use of grains for biofuels. The case for the prosecution is simply made. About one hundred million tonnes of maize from this year’s US crop will be diverted into ethanol refineries, an increase of a third on 2007’s figure. The maize used for ethanol represents almost 5% of global production of all types of grain. One in twenty cereal grains produced in the world this year will end up in the petrol tank of US cars. Other countries are also pushing ethanol, but the US has moved most aggressively to increase the use of food for fuel.

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More bad news for the poor

Two pieces of news from Tuesday 26 February. A UK investment fund is trying to raise £330m to build two large biofuels plants on the eastern coast of England. And the price of wheat rises to a new high of over $12 per US bushel in Minneapolis (over £220 per tonne) as worldwide shortages force prices ever upwards.

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Biochar can sequester carbon cheaply

Amazonian topsoil enriched with charcoalOrganic 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.

Biochar manufacture represents a way of productively storing large amounts of carbon. But the carbon in the charcoal could be burnt to generate electricity instead of being stored in soil. Current emissions trading schemes, such as the European ETS, do not allow sequestered carbon to be considered as equivalent to a reduction in greenhouse warming emissions. This is a mistake that will need to be rectified. It make more sense to use agricultural land to make biochar and biogases/bioliquids than to burn the biomass in power stations. Power stations burning wood benefit from buying fewer emissions certificates and from the renewable energy subsidy, but there is no comparable benefit from storing carbon in the soil. This is an anomaly that should be removed.

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If biofuels are the answer, we are asking the wrong question

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.

Over the last two years, this simple optimism has been eroded. Two further blows have fallen in recent weeks:

  • Nobel winner Paul Crutzen and his team showed that we may have been underestimating greenhouse gas emissions from using fertiliser. The work suggested that emissions of nitrous oxide may be far higher than previously thought.
  • Richard Doornbusch, who is attached the OECD, wrote a paper which said: ‘The conclusion must be that the potential of the current technologies of choice – ethanol and biodiesel – to deliver a major contribution to the energy demands of the transport sector without compromising food prices and the environment is very limited.’

The balance of evidence is that biofuels produced from crops grown in temperate climates save very small amounts of emissions. Moreover, the land used for biofuel crops could be used for food or biomass for energy. In tropical lands, biofuel crops may save carbon emissions. But the energy policies of richer countries may be incentivising tropical farmers to cut down forest to grow fuel crops. The effect of this almost certainly outweighs any emissions reductions.

Despite the increasingly prevalent view that biofuels are little or no improvement on fossil fuels, both the EU and the US are obliging retailers to increase the percentage of motor fuels derived from agricultural sources. This is a mistake.

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Straws in the wind: The Lib Dems' climate change paper

Both the Conservative and Lib Dem parties have produced position papers on climate change in the last few weeks. The Conservative document is over 500 pages long but contains very few specific proposals. To be harsh, it is little more than a prolonged agonising over whether the climate change problem can be addressed using conventional free-market mechanisms. The Lib Dem paper is a tenth of the length but does contain the outlines of a coherent set of policies. This article analyses the Lib Dem proposals. It shows that the Lib Dems are prepared to use the price mechanism to choke off increasing demand for aviation. The party also contemplates extending the Emissions Trading Scheme beyond the 50% of the economy currently covered. On the other hand, it makes completely clear that it has no intention of raising the prices of energy and fuels to domestic consumers.

Although the party presents itself as the only UK political institution ready to grasp the need for an economy-wide carbon price that will bring down emissions by 30% in 2020, the detailed proposals are far less radical. In the material that follows, I try to tabulate the Lib Dem ideas, focusing on whether they use price, regulatory fiat or pious hope as the proposed means of emissions reductions. As in the Conservative paper, estimates of the costs and benefits of their policies are almost completely absent from the Lib Dem paper. It is a shocking commentary on British politics that no major party is prepared to quantify exactly how it proposes to shift taxes towards polluting activities and away from other sources.

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Is organic food better for the climate?

The evidence is not quite clear enough that organic food is better for the atmosphere. The debate on whether organic agriculture reduces greenhouse gas emissions is a lively and sometimes acrimonious affair. The calculations are complex, the results depend on myriad factors that are difficult to quantify, and much research remains to be done. Those who give unequivocal answers to the question 'is organic better?' may not be recognising the extraordinary uncertainty that still surrounds many aspects of agriculture. Rather than produce a simple answer, this note offers a statement of the competing cases.

This topic has been widely researched but has produced very varying answers. There is certainly no consensus. In general, organic farming seems to be slightly better for the atmosphere than conventional cultivation, but for every ten studies that say this, five say something different. Almost all the conclusions are the subject of passionate debate.

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