Lunar eclipse may shed light on climate change

Last month's lunar eclipse not only treated skygazers to a ruddy view of the Moon – it revealed that Earth's atmosphere contains little light-blocking volcanic dust.

Some researchers say the low volcanic dust levels in the atmosphere over the last dozen years could be contributing to global warming, but others dispute the claim.

During a lunar eclipse, Earth blocks sunlight from reaching the Moon directly. But some sunlight still gets through, refracted through Earth's atmosphere. The amount varies, depending mainly on how much dust from volcanic eruptions is floating around at high altitudes.

Because dust can block sunlight from passing through the atmosphere, more dust makes for a darker Moon during lunar eclipses. "All the big dimmings of the Moon during eclipses can be attributed to specific volcanoes," says Richard Keen of the University of Colorado in Boulder, US.

Keen and his collaborators have charted the brightness of eclipses back to 1960 and for a few years around the time of the 1883 eruption of Indonesia's Krakatoa volcano.

They are using the eclipse data to track changes in the opacity of Earth's atmosphere. While most of the light deflected by particles in the atmosphere is just temporarily diverted and eventually reaches the Earth's surface, the effects of atmospheric dust can have a significant, if temporary, impact on the climate, Keen says.

Global average

Earth-orbiting satellites can measure atmospheric opacity, but only for a small part of the atmosphere at any given time. A lunar eclipse, on the other hand, conveniently gives an average over all latitudes, Keen says. Eclipse measurements are also easily compared with old eclipse records, which extend back much further in time than the satellite measurements, he says.

The most recent lunar eclipse, on 20-21 February, was a bright one, measuring a 3 – the second-brightest level – on an eclipse-rating scale that ranges from 0 to 4.

That is in line with eclipse data taken since 1995. In that time, the stratosphere has been especially clear, with very little haze-producing volcanic activity compared to the previous three decades, from 1965 to 1995, Keen says.

Because more sunlight is reaching the surface, Earth should be 0.1 to 0.2° Celsius warmer in recent years than it was back in the late 1960s, Keen and his colleagues calculate. Over the same period, the average surface temperature of the Earth has risen by about 0.6° C.

Many factors

According to the scientists that make up the Intergovernmental Panel on Climate Change (IPCC), which reports to the United Nations, most of the warming since the mid-20th century is due to the greenhouse gases released by human activity. Other factors, including fluctuating patterns in ocean circulation and slight changes in the Sun's brightness, also influence the climate.

"All of these have been contributing to a warming, adding on top of each other," Keen told New Scientist. "The difficulty is, of course, what are the relative magnitudes [of these effects]," he says.

Susan Solomon of the US National Oceanic and Atmospheric Administration in Boulder, Colorado, a member of the Nobel-prize-winning team that put together the 2007 IPCC report, says atmospheric haze, including haze from volcanoes, was included in computer models used for the report.

But she disputes Keen's conclusions. "There's no evidence for a significant warming trend over the last several decades [due to a decline in volcanic haze]," she told New Scientist. "In fact, it's exactly the opposite."

Ocean heating

The amount of haze in the stratosphere has been higher – blocking more sunlight – in the past 40 years compared to the 20 years before that, she says. So over the past 60 years, there would have been a slight cooling trend if volcanic haze were the only influence on climate, she says.

Keen acknowledges that depending on the period chosen, volcanic haze can give a cooling rather than a warming trend. But he argues that the relatively long period with a clear atmosphere since 1995 could be having a big impact on climate, especially if the extra sunshine reaching the Earth's surface could create subtle, longer-term warming effects through the heating of ocean water, as some scientists propose.

He is now compiling more precise estimates of the brightness of the most recent eclipse by comparing the Moon's brightness to that of reference stars during the eclipse. This will allow the amount of haze in the stratosphere during the eclipse to be calculated more precisely.

Original here

The clones are coming - to a supermarket near you

This week the first cattle born to a cloned cow in Britain will be sold. Opponents say this is a leap into the unknown but scientists claim it holds the key to solving food shortages

The first cattle born to a cloned cow in Britain will this week be sold at public auction. The sale - at a cattle market outside Bristol - marks the opening of a new chapter in food technology in this country, say scientists.

They expect that Dundee Paradise, whose mother was the clone of a prize-winning Holstein cow, and her brother, Dundee Paratrooper, will be bought by breeders in the first step towards the creation of new generations of cattle in Britain.

The move has been hailed by many breeders who believe that cloned cattle offer the only effective prospect of continuing to provide top-quality meat at a time when the world faces shortages in supplies of key foodstuffs. Only the creation and use of genetically manipulated plants and animals can prevent this, it is argued.

'These animals will not be sold for meat,' said Simon Best, chairman of the BioIndustry Association. 'They will cost far too much for that. Instead they will be bought by other breeders to create offspring that will go on to help to improve Britain's livestock.'

Scientists now predict that beef burgers from clone-farmed cattle will soon be approved in the United States and that Europe will eventually give the go-ahead for the sale of cloned meat as well.

This prospect causes alarm among green groups, however, and the sale of Dundee Paradise and Dundee Paratrooper - whose mother was Vandyk-K Integ Paradise 2, a clone created from cells taken from the ear of a Holstein, a milking cow, in the US - may become the focus of protests by groups opposed to the creation of what they call 'Frankenstein' foods. They say the manipulation of animals in the laboratory could trigger unforeseen, potentially harmful changes to beef and other meats. This charge is vigorously rejected by scientists, however, and by bodies such as the Food Standards Agency and the European Food Safety Authority.

More to the point, cloned meat will become increasingly important, say scientists, as Britain strives to make its farms more environmentally friendly by reducing its use of nitrates and other harmful chemicals as well as its output of carbon dioxide and other greenhouse gases. In the case, of Dundee Paradise and Dundee Paratrooper, this has been done by creating a clone of a top milk-producing Holstein. Such animals mean that more milk can be generated on a farm without increasing use of fertilisers and fodder.

'Normally it takes generations to introduce new improved traits into cattle - by carefully cross-breeding different cows and bulls,' added Best. 'However, by creating a clone of an ideal animal, in this case one that is a top milk-producer, you have done it in a single generation. Thus you can make improvements to livestock, and to the nation's beef and milk, far more quickly than by using traditional breeding techniques.'

The only concern for UK scientists is the fact that the technology used to create the cattle was invented in Britain - by the team, led by Ian Wilmut and Keith Campbell, responsible for the cloning of Dolly the Sheep. But now virtually all commercial cloning work of livestock is done in the US, and farmers and breeders in Britain, as with Dundee Paradise and Dundee Paratrooper, have to buy from companies on the other side of the Atlantic.

In addition, news of the sale of the cattle - which are owned by Smiddiehill Holsteins, based at Albrighton, Shropshire - comes as ministers and their advisers are warning that significant food shortages could arise in Britain unless urgent moves are taken to ensure that the country adopts a sensible, balanced food policy. A national debate on the issue is urgently needed, they say.

The problem is that consumers expect cheap and plentiful meat, fruit, vegetables and groceries, yet their production causes harmful greenhouse gases and is unsustainable because of the UK's limited availability of land, oil and water, said Tim Lang, of the government's sustainable development commission (SDC). 'We've had an orgy of choice unparalleled in human history in the past 50 years, but many analysts agree that, unless there is fundamental change, food supply chains could even collapse,' said Lang, who is also professor of food policy at City University, London.

Suggested ways for transforming the attitudes of consumers and the food industry include rationing by putting up prices and encouraging supermarkets to stock a smaller range of identical products. But encouraging the public to behave differently is a complex process, added Lang. More than 30 per cent of people claim to care about companies' environmental and social records, for example, but only 3 per cent reflect these beliefs in their purchases.

'We are missing the point if we put all the onus of choice onto consumers,' said Lang. 'Choice is part of the problem, not the solution. Do you load responsibility on every consumer or do you constrain their choice? We can't ask consumers to spend 24 hours thinking about which of an aisle-full of nearly identical products to buy when so many are inappropriate - too high in carbon, for example.'

Instead, said Lang, policies need to be introduced that shape the choices consumers make. 'We all like to think we choose our diets but choice is already structured by history, price and policy.'

Production, distribution and consumption of food in Britain is responsible for around a fifth of total UK greenhouse gas emissions. The Stern report in 2006 said agriculture alone globally accounts for 31 per cent of emissions.

'The UK situation is being stressed not just by water and oil shortages but also land availability, labour skills and affordability,' said Lang, who is calling for a national debate about future policies to engage the public and how to transform consumption. 'We have to involve the public in this process of change.

'So far, expert debate is about the existence of problems and not enough is about involving the public,' said Lang, who will discuss the issue in early March in a speech at City University titled Food Security: Are we sleep-walking into a crisis?

'There are those who believe we can use hi-tech solutions to get out of the problem and others just believe markets will resolve it. But the key will be public acceptance. The paradox is that Britain was never better fed than during the Second World War, when rationing was in place. This was because the public saw its purpose; it didn't like it, but it accepted necessity. In a future crisis, rationing will be designed for sustainability, not just health and equity.'

Lang's call is supported by the Sustainable Consumption Roundtable - a joint initiative between the SDC and the National Consumer Council (NCC), which explores ways that the government can help create a shift to more sustainable lifestyles and is funded by the Department for Environment, Food and Rural Affairs and the Department for Business, Enterprise and Regulatory Reform .

'There is not enough evidence to suggest that consumers on their own are able to change mainstream product markets,' said Ed Mayo, chair of the Roundtable and chief executive of the NCC.

"'Choice editing" for quality and sustainability by regulators, retailers and manufacturers has been the critical driver towards more sustainable consumption. Early announcement of legislation to set minimum standards can also drive a virtuous cycle of rapid innovation and further choice editing,' he added.

Original here

Suicidal Anorexics: Determined to Die?

Deciding not to eat sounds to most people the very definition of suicide. It is perhaps no surprise then that a new study concludes that when anorexics choose to take their own lives, they tend to employ some of the most lethal methods available. Yet, in many ways, the new research conducted at the University of Vermont represents a landmark shift in how doctors understand suicidal tendencies in patients suffering from anorexia nervosa.

Anorexia has the highest mortality rate of any psychiatric disorder. But psychologists previously believed that those high rates of death were due to patients' already deteriorated physical state. The hypothesis was that these are people already on the verge of death — they were so malnourished and underweight that even the slightest suicide attempt could easily lead to death.

The new study's authors have shown this assumption is wrong in most cases. Extrapolating from nine case studies of anorexics in Germany and Boston, they concluded that such suicides are not simply a call for help gone wrong, but that anorexics are genuinely determined to die when they attempt to kill themselves. Some of the disturbing means the nine patients profiled used included jumping in front of moving trains, ingesting dangerous household cleaners and setting oneself on fire. These patients also tended to isolate themselves before their suicide attempt, most likely in order to reduce the possibility they would receive life-saving help. "We established that these patients' death had little to do with their low body weight," says lead author Jill Holm-Denoma, a professor of clinical psychology at Vermont and an expert on treating eating disorders. "The methods that they chose could have killed anyone."

Holm-Denoma's work reaffirms, among many others, a 2003 Harvard University study that concluded anorexic women are, by nature of their illness, self-destructive, leading them to have a likelier propensity toward suicide as well as alcohol abuse. That study of about 250 women suffering eating disorders showed the risk of death by suicide among by anorexic women to be as much as 57 times the expected rate of a healthy woman. Research on suicide in 2006 by psychologist Thomas Joiner at Florida State University took those conclusions one step further and suggested anorexics habituate to pain, making them fearless of death, and thus more likely choose a more lethal means to end their lives. Holm-Denoma's research, however, is one of the first studies of the specific methods that suicidal anoxerics use. The gruesome methods they chose as well as how they isolated themselves from rescue, Holm-Denoma says, leaves little doubt that they wished to die.

The new findings, to be published this spring in the Journal of Affective Disorders, come during this year's National Eating Disorder Awareness Week. As many as 10 million women and one million men in the United States suffer from an eating disorder such as anorexia or bulimia, according to the National Eating Disorder Association (NEDA). Females between the ages of 15 and 24 are 12 times more likely to die from anorexia than all other causes of death, the NEDA reports. And suicide is the primary cause of death for anorexics, greater even than starvation. Holm-Denoma stresses her research highlights how seriously treatment providers must take suicide risks amongst those suffering from eating disorders. "The likelihood of whether a patient wants to lethally hurt herself must be assessed right away," Holm-Denoma says, adding, "Addressing psychiatric needs must be paramount."

For the families of anorexics, Holm-Denoma's research only affirms their worst fears. One of the biggest frustrations these families face when their loved one is diagnosed with anorexia is how they can obtain affordable psychiatric help. Insurers rarely pick up the bill. Most health plans argue that eating disorders require mental health treatment not covered by most policies and therefore refuse to pay for long-term care. In the direst cases, health plans will often cover a brief hospitalization to stabilize a patient's weight. But once she begins to gain weight again, she will be sent home. "The biological crisis may have passed," says Barbara Anthony, a Boston-based lawyer and executive director of Health Law Advocates, an organization that aids families. "But hospitals and health plans have done little to provide these patients with the mental health care they desperately need."

Meanwhile, costs related to in-patient treatment for an eating disorder can range from $25,000 to $30,000 a month. Many families are forced to take out second mortgages or deplete savings. Such situations are tragic, Holm-Denoma says. "Anorexia is one of the most serious psychiatric diseases our society faces," she says. "Our work shows even further that more needs to be done to prevent it."

Original here