Sir, The rising price of bread is a direct result of biofuels development.

Maize prices have doubled since President Bush stated his aim in January last year of cutting US dependence on foreign oil. The amount of US maize being turned into bioethanol for vehicles tripled in five years to 50 million tonnes in 2006, more than 15 per cent of the total American crop.

The International Energy Agency has stated that demand for crops for biofuels will rise from 41.5 million tons of oil equivalent (Mtoe) in 2010 to 92.4 Mtoe by 2030. With government subsidies it will rise even faster – in 2012 an EU directive comes into force mandating 5.75 per cent of all fossil fuel in vehicles to be replaced by biofuels. The researcher Hans Wilhelm Windhorst has estimated that, for the EU to reach its 2020 target for biofuels, a quarter of all EU arable land will have to be turned over to biofuel production.

As James Lovelock has pointed out, biofuels are the most environmentally destructive of all energy sources, requiring huge areas of land. Yet they will be a nice earner for oil companies who fear that cars could be run on batteries charged from nuclear reactors. The writer and activist George Monbiot has claimed that on the basis of 1.45 tonnes of transport fuel from rapeseed per hectare, some 29.5 million hectares would be required to fuel the UK. Our total arable land is 5.7 million hectares.

TERRI JACKSON, Bangor, N Ireland

Sir, Large fields of miscanthus and willow crops could cause as much harm to wildlife as the switch from spring to autumn sowing 35 years ago (“How seeds of technology could turn the country green”, Sept 11).

Farmland birds have declined by 40 per cent since then. We need research to find ways of preventing adverse impacts on wildlife where fuel crops are to be sown over large areas. This is urgent because public money is to be spent on subsidising this major land-use change.

DR SUE ARMSTRONG BROWN, Head of Countryside Conservation, RSPB, Sandy, Beds

Sir, 1816 was “the year without a summer”, thanks to the Tambora eruption that veiled much of the world with dust, screening out the sun. Yet in 1817, while still in the grip of the Little Ice Age, the Royal Society was so worried that 2,000 square leagues of sea ice around Greenland had disappeared within two years, and massive flooding was taking place in Germany, that the President wrote to the Admiralty advising an expedition to find out what was the source of this new heat. Perhaps, when similar things are happening 190 years later, the Royal Society should accept that anthropogenic carbon dioxide is unlikely to be the main, or only, driver of “global warming”.

DR DAVID BELLAMY, Bishop Auckland, Co Durham
DR JOHN ETHERINGTON, Llanhowell, Pembs

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