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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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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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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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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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