When oil runs out
Jessica Marshall suggests it will be “biology to the rescue” in the face of oil shortages (7 July, p 28). This appears to be at odds with Andy Coghlan’s article in the same issue (p 15), in which Helmut Haberl is quoted as saying: “…we’re asking for trouble… if we expand production of biofuels” and “If we want full-scale replacement of fossil fuels by biofuels, this would have dramatic implications for ecosystems.”
From David Ayre
Your cover for the 7 July issue talks of “Living Without Oil” and the corresponding article is entitled “Who needs oil?” Given that the article talks only about substitutes for the 3.4 per cent of oil used to produce petrochemicals, and barely mentions the 70.6 per cent that is used for transport fuels, I think both the cover line and the title exaggerate. Please follow up by running the numbers on transport fuel substitution.
Nelson, New Zealand
Flexi-law amendments
I wholeheartedly agree with Paul Davies that what we regard as physical laws may well have been different at earlier times in the universe (30 June, p 30). However, the attempts to rationalise this phenomenon in his article are clearly flawed because they assume that the laws of quantum physics and information theory are themselves constant and multi-universal.
The problem is clearly illustrated when Davies asks us to consider the universe as a giant computer, with a finite capacity for performing calculations, and later proposes that this capacity (the Lloyd limit) potentially leads to ways of observing the effects of changing laws. Lloyd’s limit and, for that matter, the size and history of the observable universe, are arbitrarily fluctuating quantities if the laws of physics change with time or across multiple universes.
Since there is no possible way of accounting for the infinite array of possible alternative physical laws, the problem of reconciling current and past laws is intractable.
From Dave Holtum
Aren’t the laws of physics more the result of our need to make patterns of everything, rather than any “true” representation of reality? Things only have a name and a category when we give these to them 鈥� everything is really different to everything else. Once you start grouping things you can do some useful generalisation 鈥� but this also leads to issues that are a result of the process of generalisation.
Bath, Somerset, UK
From Mark Gendala
May I suggest you recall and destroy all copies of Davies’s article. Otherwise the theories expressed in it might be affected through reverse quantum causality, should anyone laugh at them in the future.
Elwood, Victoria, Australia
Ocean of doubt
Victor Smetacek advocates research into seeding the oceans with iron to increase the growth of calcium carbonate-secreting phytoplankton as a mechanism for sequestering carbon on the sea floor (30 June, p 9). He, and others advocating this, should inform themselves about the variation in carbonate solubility with depth in our oceans.
Below the carbonate compensation depth (CCD), calcium carbonate is soluble in seawater. Calcium carbonate falling below the CCD dissolves and eventually returns to the sea surface through oceanic upwelling. As a result, there are no calcium carbonate-rich sediments on modern sea floors, except in regions of relatively shallow waters 鈥� where the sea floor is above the CCD.
Even if iron seeding were carried out in shallow seas, because phytoplankton are free-floating they could easily be carried into regions of deeper water before dying and sinking to the sea floor. In that case the planned carbonate sequestering would be quite ephemeral and the investment unwarranted.
Plankton periodicity
Hans van Haren’s explanation for zooplankton’s migrating synchronously with the phases of the moon is that it “has nothing to do with physical processes, but a biochemical clock could explain it” (7 July, p 17). The self-evident next question is: how and why did the biochemical clock become synchronised with the phases of the moon in the first place?
Languages evolve
Dan Dediu and Robert Ladd suggest that the brain development genes linked to non-tonal languages are of more recent origin than those linked to tonal languages such as Chinese (2 June, p 15). The usual view of linguists is that tonal languages are the more recent development, evolving from earlier non-tonal inflected languages 鈥� those with grammar dependent on word endings and the like.
I have read that the last vestiges of inflection can still be found in the earliest records of Chinese, but that over the centuries all inflections were lost as Chinese developed into a monosyllabic language. It was the development of monosyllabism which then led to the emergence of tone as a way of differentiating the meaning of the many homophones that resulted.
This would suggest that, if indeed there is a genetic component to the ability to learn tonal languages, we would expect the variation linked to tonality to be the more recently evolved.
Can anyone explain this apparent contradiction?
Uranium reserves
Guy Cox questions the logic behind a major building programme for nuclear power stations (23 June, p 22) when, according to David Cohen’s report, uranium deposits will be exhausted in 59 years (26 May, p 34).
Data from the British Geological Survey indicates that world production of uranium metal in 2005 was about 42,000 tonnes, from countries including Australia, Canada, Kazakhstan, Russia, Niger and Namibia. Normally reliable figures from the Organization for Economic Cooperation and Development suggest that current “recoverable resources” of uranium globally are about 4.74 million tonnes, well over 100 years of supply at current rates of consumption.
Very little exploration for uranium was carried out between 1980 and 2003. Driven by recent price rises, exploration activity is now intense and new mines are under development in Africa, Asia, Australasia and North America. Past experience suggests that further finds are inevitable.
The uranium-copper-gold deposit at Olympic Dam in South Australia is of a type that was completely unknown 30 years ago. It now constitutes a significant portion of the global uranium reserve.
Boycott or not?
The two letters by Norman Klein and Mike Barnes on boycotting Israeli academic institutions show two aspects of the issue but do not go far enough in the analysis (7 July, p 20). We need to ask: how is public opinion affected in the concerned countries? Who is really hit by a boycott? What are the consequences of the boycott and do they operate in the direction the boycott aims for?
An academic boycott hits scientists, who are likely to be among those Israelis who are aware of the complex problems of the Israel-Palestine issue and who are, I believe, less prone to extremism. They may influence public opinion, but scientists are probably not sufficiently powerful to change the way Israel acts in relation to Palestine.
The real decision-makers 鈥� politicians, business people, labour unions 鈥� are not really hit by any boycott of academic exchange. An economic boycott could affect them. Concerned people in Europe and the US, the main markets of Israel, could boycott goods and services from companies which are not actively working for peace and which do not treat equally Israelis and Arabs, whether Palestinians or “second-class” Israeli citizens.
Go out to a living fire
David Prichard mentions seven criteria for recognising a life form: assimilation, excretion, growth, locomotion (movement), reaction to stimulus (irritability), reproduction and respiration (7 July, p 21). I would suggest all you need to do is travel to another planet and start a fire. Fire exhibits all seven vital functions, and accordingly a fire on Mars would count as an alien life form.
Of course in most cases an oxygenated atmosphere would be necessary for fire to survive and procreate, as I observe at work as a firefighter. But the same could be said for many species on Earth.
Pedantic syndrome
In her thought-provoking article on “impossible awakenings” Helen Phillips says that persistent vegetative state “is not so much a diagnosis as a symptom…” (7 July, p 40). At the risk of pedantry, I have to say that PVS patients cannot by definition have symptoms. Symptoms are subjective and reported by the patient 鈥� for example, nausea or itching. Objective observations 鈥� such as rash or pallor 鈥� made by someone such as a doctor are called signs.
Many mansions
Jay Bear says the Bible contradicts itself from one chapter to the next when listing the order of creation: plants, animals, man, woman and so on (30 June, p 23). Obviously, creation is in a quantum superposition until some outside observer measures it.
For the record
鈥� We said that Russia is claiming 1.2 square kilometres of oil and gas-rich Arctic sea floor around the North Pole (7 July, p 4). That should have been 1.2 million square kilometres.
鈥� We said the Pierre Auger cosmic ray observatory in Argentina was 3000 kilometres square (7 July, p 8). It actually covers 3000 square kilometres.
鈥� Apologies to Veronica Beccabunga who was misnamed by Feedback (7 July).
Sulphurous aliens?
I was interested by Douglas Fox’s discussion of the possibilities of life based on a biochemistry other than what we know (9 June, p 34). It seems to me that there is one element that has been overlooked. Sulphur is second only to carbon in its ability to catenate, or form covalent bonds between one sulphur atom and another. Its chemistry is also given variety by its ability to take on a range of oxidation states, namely -2, +4 and +6.
There is one body in the solar system whose surface is composed largely of sulphur compounds. Jupiter’s moon Io has large active volcanoes spewing out such compounds, which cover the geologically active surface. If life forms based on an exotic sulphur chemistry could exist, than maybe somewhere below the surface of Io would be a suitable environment for them.
Badger balance
Discussions about tuberculosis, badgers and cattle in the UK (or elsewhere) omit the trend since the 1960s of keeping cattle in large herds together indoors for intensive farming, mostly bolstered by various agricultural grants, subsidies or other economic pressures (see, for example, 23 June, p 9).
Keeping any group of animals indoors in close quarters, in conditions of poor ventilation, stress or restricted diet, whether they be humans or cattle, creates the breeding grounds for diseases such as tuberculosis. It should be no surprise that cattle in these conditions are susceptible. The conditions under which cattle being monitored for studies are kept (and those of neighbouring farms) must be taken into account.
When I was dairy farming in Lancashire in the UK, with cattle outdoors in the fresh air, they didn’t contract anything from local badgers. If TB is transmissible from badgers to cattle, then the reverse infection path is just as likely. Is continuing to blame the badger (or human) for the source of TB any excuse?
On top of all this is the possibility that existing government compensation schemes could encourage unscrupulous vets or farmers to give a TB diagnosis where none existed.
Carbon rebound
I read the results of your US poll on global warming with interest (23 June, p 16). It said that the results of the poll challenged “some common preconceptions”. However, it went on to conclude that, of the options presented to them, the American public preferred the ones that cost them the least and that they were suspicious of taxes. Not much challenge there.
In all that has been written about global warming in recent months, not much 鈥� if anything 鈥� has been made of another way in which financial considerations undermine current attempts to encourage people to reduce their carbon dioxide emissions.
“Carbon shifting” is the tendency for people to increase emissions in one area of their lifestyle as a result of cutting emissions elsewhere. It is frequently said that being good to the environment is also good for your wallet. Walking to work, turning down the heating and switching off rather than using standby are all good for the environment and all save money.
Crucially, how good they are for the environment depends on how those savings are spent. If cycling to work means I can now afford an extra city break then my lifestyle may have become more damaging to the environment rather than less so.
Wealth destruction
Fat is a climate change issue, Ian Roberts writes (30 June, p 21). But there is a bigger question over the rich. Usually, talk about wealth and sustainability deals with north-south divides, with rich and poor nations. This grand categorisation obscures the large and growing disparities in wealth within countries and the pan-national, multi-location character of the reinvented and expanding jet-set classes, whose consumption decisions disproportionately affect the environmental future of all populations.
The world’s wealthiest people are a rather elusive group, despite their popularisation in published “rich lists”. Below them, a much larger and growing cohort of high-net-worth individuals (HNWIs) has emerged 鈥� those with assets of over $1 million, excluding their primary home.
In 2005-2006 the number of HNWIs grew by 8.3 per cent to around 9.5 million worldwide and their combined purchasing power grew 11.4 per cent to $37.2 trillion 鈥� an average of $4 million each. Though the majority come from traditionally wealthy countries, the highest growth rates are in places such as India, South Korea, China and Russia 鈥� where wealth inequalities are also stark.
As wealth and income increase so the consumption of carbon-intensive products such as meat and gas-guzzling cars rises. The wealthy are more likely to take carbon-heavy private jets and to fly more in general, when most of the world’s population have no possibility of flying at all. But carbon emissions are only part of the environmental problems associated with concentrated wealth. For example, the wealthy can afford the astronomical prices of products derived from rare species, helping to drive them to extinction. Criticising wealth, its increasingly uneven distribution and consumerism is one of the great taboos of modern society, but given the scale of the environmental crisis we face, it has become an imperative.
It is surprising how little we know about the environmental cost of today’s wealthy lifestyles or how sustainable affluent lifestyles might be created, but we can safely say that targeting the consumption and lifestyle habits of these relatively few individuals will bring the largest benefits in terms of progress towards sustainability and social justice.