No option but to cut the use of cars.

My letter was published in "The Independent" newspaper today (October 16th), which reinforces the conclusions made in previous postings about the realities of biofuels. I estimated the quantities in terms of bioethanol, since the numbers suggest this form of fuel to be better than alternatives such as biodiesel or biohydrogen. I have copied the text below.

Sir: There is no choice but to cut car use by 90 per cent (Letters, 12 October). To replace even 5 per cent of the fuel consumed annually in the UK by bioethanol would require turning over about 6,300 square kilometres of arable land for the purpose, or 10 per cent of the total arable area of the UK, which would conflict with food production.

The Royal Society of Chemistry mentioned, in their recent policy bulletin, converting waste products from existing agriculture to ethanol, for example, wheat straw. This sounds a perfect solution but it would provide the equivalent of just 6.5 per cent of the total fuel presently used.

There is no way we can produce enough ethanol to match our present level of fuel use, either using biomass waste or without compromising food production. On the other hand, if we move to systems of energy efficiency, living in localised communities, which would cut fuel demand (that is, car use) by 90 per cent, then 6.5 per cent of that remaining 10 per cent begins to look significant.

Otherwise, we can neither break our dependency on imported fuels nor meet the government's targets to reduce CO₂ emissions. Details of these and other calculations on biofuel energy provision and other renewable sources can be found at http://ergobalance.blogspot.com.

PROFESSOR CHRIS RHODES

READING, BERKSHIRE

I note also, that the Earth has just reached the point of ecological debt (that was on the 9th of this month actually), beyond which humankind begins to live beyond its ecological means. A green group, called the New Economics Foundation (NEF) has calculated that now we are "eating the planet" - overwhelming natural capacities to deal with pollution of the atmosphere and water, and to replenish food and fuel supplies. The impact of nearly 6.5 billion people is manifest in degradation of the sea ecosystems, deforestation, impeding shortages of fresh water, and overfarming the land to grow crops (in significant amount for grazing animals). The lungs of the Earth (the rainforests) are heavily depleted, but vital to exchange oxygen for carbon dioxide which is absorbed in the process as part of the natural regulation mechanism for CO2. Oil reserves (as we have noted) are in rapid decline, and at a draw-off rate of 84 million barrels a day (over 30 billion barrels each year) are likely to run-out inexorably from any time now, contributing CO2 in the process.
There are too many of us to continue living at present (and growing) levels of resource consumption. The nightmare of a "Die-Off" similar to the fate of bacteria populations which proliferate aplenty when food is in ample supply, but die-off as the sustaining resource becomes compromised. It is thought that the world population, which has grown fed by oil-derived fertilisers, could fall from over 6 billion to around 2 billion, which some estimate to be the true carrying capacity of the planet. It is not feasible that the developing nations such as China can ever live at a Western standard and level of consumption, and neither can the industrialised countries maintain their material status quo. We must in all nations seek a lower-energy way of living, probably based around relatively small communities with populations of 20,000 or less, which I have dubbed "pods", provided for mainly by sustainable local resources, or ultimately we will not survive.