What price more food?

Letters– What price more food? From Peter Sutton I was very interested and pleased to read Debora MacKenzie’s informative article on the global food crisis (14 June, p 28). I do feel, though, that she overstates the case against biofuels as a technology for the future. Crops such as wheat and rice produce over 3 tonnes of straw per hectare – which we could put to many carbon-efficient uses, for example, as packaging or as a source of waxes, given time and resources to research them. There is vast potential to increase production of crops such as sugar cane and sugar beet for bioethanol production. In Europe for the past 50 years sugar beet has been grown under a quota system to limit production. Guildford, Surrey, UK From Catriona Millican Your article contained a statement I have often seen before, that to produce 1 kilogram of beef you need 6 kg of grain; for 1 kg of chicken you need around 2 kg of grain; and so on. The implication is that if everyone would only stop eating beef, we would have six times as much food in its place, and if those pesky people in developing countries would stop supplementing the tortillas, chapattis and rice, which have always made up the bulk of their diet, with unnecessary meat, we would all be better off. Of course most westerners eat too much protein, but many people around the world don’t get enough. The desire to replace a nutritionally poor diet with one which contains enough protein to thrive hardly qualifies as destructive greed. To replace meat with grain would be to invite malnutrition. Surely the comparison should be like for like – meat for pulses. It seems that yields per hectare of pulses are around one-third those of grain, so 1 kg of beef is equivalent to 2 kg of pulses and 1 kg of chicken is equivalent to just 20 | NewScientist | 5 July 2008

700 grams of pulses. Suddenly, giving up meat doesn’t look like such an easy solution. Glasgow, UK

From Susan Lees I find it astonishing that neither your editorial (14 June, p 3), nor Debora MacKenzie’s article, mentions encouraging family planning as one part of the solution, to slow the growth of population. London, UK The editor writes: ● The population bomb has already gone off. If every woman now of fertile age has only two children on average, we’re still headed for 9 billion people in 2050. The issues now are unemployment and hunger, not contraception, although many people still need easier access to the contraception they want. Reproductive rates are already declining fast: if this trend continues, population will fall after 2050. The only ways to slow it further would be an even more rapid fall in birth rates – which would need impossibly rapid cultural change – or a massive rise in mortality.

Visceral politics From George Lakoff, Cognitive Science and Linguistics, University of California, Berkeley Owen Flanagan’s description of my book The Political Mind: Why you can’t understand 21st-century American politics with an 18thcentury brain, (31 May, p 48) left

much to be desired. The book has two parts: one scientific and one pointing out the political consequences of the science. There is a received view of mind, absorbed into popular culture and similar to that of the philosopher René Descartes, that I refer to as “Enlightenment reason”. It goes like this: reason is conscious, disembodied, dispassionate, literal (it fits the world directly), logical (it leads from facts to correct conclusions), universal and serves self-interest. This is widely taken as defining “rationality”. I surveyed results from neuroscience and the cognitive sciences that contradict all these supposed properties. Reason is mostly unconscious and physical – it uses the brain. It requires emotion and uses frames, metaphors and melodramatic narratives. It also varies depending on world view and is used at least as much in the service of empathy as self-interest. This is real reason, how people really think, and it requires a new account of rationality that calls for a New Enlightenment. Each of these results is crucial for understanding politics. Conservatives, using marketing techniques taken from psychology, have marketed their big ideas effectively: the nature of national security, government, the market, taxes, responsibility, family values, religion, and so on. Progressives have failed to build institutions (such as think tanks) to get their big ideas out in public honestly. An awareness of brain mechanisms could help map effective communication. The Political Mind is an exercise in the democratisation of knowledge. It opens up the cognitive science of politics for all to see. Journalists, policy-makers, most economists, and even many academics are stuck on the old view of reason, which leads them to fall prey to effective political marketing, mostly from the conservative side. Berkeley, California, US

It’s a wonderful cosmos From Stephen Wilson As another atheist without qualms, it worries me that Lawrence Krauss so badly misses the point in his diatribe against religious belief (7 June, p 50). It does no good to caricature the “intellectually lazy creations of fundamentally ignorant minds”. Religious people don’t merely see the heavens as “more intimate and more magical”; they see them as more meaningful than we do. It is lazy to underestimate the true horror science and especially Darwinism presents to the religious: that the universe can be sensibly understood to be without purpose. They take this to mean that life has no meaning. We face today an urgent practical need to reposition ethics and a good deal of the law within an amoral universe. This inherently philosophical project is arcane, highly technical and inaccessible to most, including scientists. Krauss is not going to redress the yearning for meaning with his appeal to squillions of beautiful supernovae. Five Dock, New South Wales, Australia

From Merle Arrowsmith I am usually a great fan of Lawrence Krauss’s commentary – except when it comes to his pitiful attempts at denigrating religion. What you consider to be the representatives of faith worldwide are, statistically speaking, a loud but shrinking minority of (mainly American) fundamentalists who think they have to be afraid of www.newscientist.com