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Newsletter 13th July 2007

- Spud they don't like - Should we worry about milk from clones? - Ruminants, methane and climate change - The Sun and climate change

Spud they don’t like

This week, it has been reported on the Indymedia website that the only current GM potato field trial in the UK was destroyed over the weekend. The trial was of blight-resistant potatoes, and run by NIAB (the National Institute for Agricultural Botany) in Cambridge. Part of the message, from “Digger” reads “The potato plants were already flowering, spreading genetic contagion into the surrounding countryside. Public concern and demonstrations had failed to sway NIAB, the National Institute for Agriculture and Botany, who are carrying out the five-year trial on behalf of BASF.”
 
Such wilful destruction is inexcusable, and use of such emotive terms as “genetic contagion” certainly provide no justification for it. It is evident that a small group of people are dead set against agricultural biotechnology, and will try any means to get their way. Do they realise the problems which potato blight can cause? Not only was it the disease which led to the massive loss of life and enforced migration of the Irish potato famine of the 19th century, but it still causes crop losses amounting to about £2 billion annually.
 
Farmers in the UK routinely spray their potato fields with fungicide as much as 15 times a season to prevent blight, at a cost of about £200 per hectare. In developing countries, this is not usually an option, and blight causes significant crop losses against a background of yields which are already low. In-built blight resistance has the potential to raise yields and eliminate most spraying, but this small group of activists ignore these benefits.
 
Instead, they focus on what they see as the risks. They ignore the fact that the trial they have destroyed was set up – with the approval of scientific experts – to look at the performance and environmental impact of the crop. They also ignore the reality of potato cultivation. Potatoes are not raised from true seed; instead “seed” potatoes (small tubers) are planted, to give a field of genetically identical clones. Although the plants do flower (some varieties more so than others), pollination of other potato plants within the field is minimal, and, since the crop was introduced from the Americas, there are no natural relatives with which they can cross-pollinate.
 
The likelihood of gene flow from potatoes is therefore pretty remote. In the unlikely event that it did occur, the transference of blight resistance to plants which are not in any case susceptible to the disease offers no selection advantage. Hardly “genetic contagion”. Whatever the motivation of the vandals, be it political, religious or other, the effect is only to ruin a perfectly sensible scientific experiment.
 
In the meantime, we are told that another GM potato from the same company, producing high-amylopectin starch for industrial use, is reaching the end of the EU approval process. Although a number of new approvals have been forthcoming in the last year or so, all have been for crops to be imported rather than grown in Europe. Approval of this potato for cultivation would give a clear signal that the regulatory system, flawed and politicised as it is, can finally give the result recommended by independent scientists.
 
Should we worry about milk from clones?

Eating cloned potatoes is one thing, but what about cloned animals? The US Food and Drug Administration last year concluded that there were no human health or safely risks associated with meat or milk from cloned animals, and the European Food Safety Agency is currently conducting its own study. The problem seems to lie more in the perception than the reality. Clones are simply genetically identical individuals (this includes twins of any species, including humans), and there is absolutely no reason to suppose that cloned dairy cattle, for example, would produce milk which differed in any way from that of more conventionally bred stock. But there is still the ethical dimension; perhaps we are in danger of moving beyond boundaries which society will accept. But in the lifetimes of many of us, procedures which initially caused real concerns – heart transplants and in-vitro fertilisation, for example – are now considered normal. Will we think the same about cloned animals in ten years’ time?
 
Farm animals today are the result of hundreds of years of selective breeding, and bear little resemblance to their wild cousins. The proposal is to take this a step further, by cloning particularly fine examples of certain animals and then using them to breed further generations. Already, prize bulls sire thousands of offspring via artificial insemination; cloning merely makes those bulls even more valuable. The real issues raised are about animal welfare and the ethical nature of our use animals for our own needs. To us, the well-controlled use of cloning for livestock farming seems a natural next step, but to some it will look like a slippery slope. Time alone will tell what the majority will find acceptable.
 
Ruminants, methane and climate change

It is well known that, weight for weight, methane has a much greater potential to warm the Earth’s surface than does carbon dioxide, although it is present in the atmosphere at much lower levels. But reducing fossil fuel use will not cut methane emissions: the majority comes from such agricultural sources as rice paddies and livestock farming. In particular, ruminants release large quantities of methane into the atmosphere because of the action of fermentation of feed by bacteria in their digestive systems. Cows, for example, produce up to 500 litres of the gas each day, mainly by belching, and there have been efforts in recent years to find ways to reduce this.
 
A group from IGER, the Institute for Grassland and Environmental Research in Aberystwyth, has now publicised some of their work, which includes developing new types of feed and breeding grasses with a higher sugar content. However, one of the most intriguing suggestions is to add garlic extract to feed, which has the potential to reduce methane emissions by 50%. Since cows are responsible for about 3% of the UK’s total greenhouse gas emissions, this is significant. However, other measurements suggest that, for as yet unknown reasons, the level of methane in the air has fallen back somewhat in recent years. Clearly, there is still plenty of research needed.
 
The Sun and climate change

A group of researchers, led by Mike Lockwoood of the Rutherford-Appleton laboratory, has recently published a paper in a Royal Society journal in which they investigate the purported link between solar activity and global climate. Their widely-reported conclusion is that, since solar activity has been declining recently, it cannot explain the rise in average temperatures over the last two decades. According to Dr Lockwood, “this should settle the debate”.
 
Maybe. This study is certainly a useful contribution to our current imperfect state of knowledge, and makes any simple short-term solar activity-climate link look most unlikely. However, in our opinion, this is not proof positive that anthropogenic carbon dioxide is the overwhelming driver. To make it clear, we do not say that the IPCC view of climate is wrong, just that it is supported by essentially circumstantial evidence and still has a number of important areas where observation differs significantly from theory (relative warming of the upper troposphere and Earth’s surface, for example). In recent weeks we have also seen apparently conflicting views on the melting of terrestrial ice sheets, with some researchers suggesting that the Greenland icecap is more vulnerable than previously thought and others reporting that it has been more resilient than expected to significant historical temperature changes. There is plenty of work still to be done.
 
The greatest progress is likely to be made by keeping as open a mind as possible on evidence which may threaten a key theory, whether it relates to carbon dioxide or solar activity. In the meantime, we have real and present dangers from extreme weather, whatever its cause. We also cannot continue to rely almost exclusively on fossil fuels to supply our energy needs. Lots of ingenuity and resources will be needed to protect communities from the vagaries of the weather and to provide energy security for all.