Preposterous Guru

Outbreaks of mirid bugs, which can devastate around 200 varieties of fruit, vegetable and corn crops, have risen dramatically in the past decade, as cotton farmers have shifted from traditional cotton crops to GM varieties, scientists said.

Traditional cotton famers have to spray their crops with insecticides to combat destructive bollworm pests, but Bt cotton produces its own insecticide, meaning farmers can save money by spraying it less.

But a 10-year study across six major cotton-growing regions of China found that by spraying their crops less, farmers allowed mirid bugs to thrive and infest their own and neighbouring farms.

The infestations are potentially catastrophic for more than 10m small-scale farmers who cultivate 26m hectares of vulnerable crops in the region studied.

"The news is not good," said Ahmed Djoglaf, executive secretary of the UN Convention on Biological Diversity (CBD).

"We continue to lose biodiversity at a rate never before seen in history - extinction rates may be up to 1,000 times higher than the historical background rate."

The global abundance of vertebrates - the group that includes mammals, reptiles, birds, amphibians and fish - fell by about one-third between 1970 and 2006, the UN says.

But the best efforts of the British energy giant have yielded no progress so far, and engineers are frantically constructing a giant dome that could be placed over the leaks as a back-up plan to try and stop the oil spreading.

The US authorities said they were considering a controlled burn of oil captured in inflatable containment booms floating in the gulf to protect the shorelines of Louisiana and other southern states.

"I am going to say right up front: the BP efforts to secure the blowout preventer have not yet been successful," Rear Admiral Mary Landry said, referring to a 450-tonne machine that could seal the well.

Asked to compare the accident to the notorious 1989 Exxon Valdez oil tanker disaster, Mr Landry declined but said: "If we don't secure the well, yes, this will be one of the most significant oil spills in US history."

The US government promised a "comprehensive and through investigation" into the deadly explosion that sank the platform and pledged "every resource" to help stave off an environmental disaster.

The rig, which BP leases from Houston-based contractor Transocean, went down last Thursday 130 miles southeast of New Orleans, still burning off crude two days after a blast that killed 11 workers.

The Engineering the Future alliance of professional engineering bodies says this is unsustainable, given population growth and climate change.

It says countries such as the UK must help poorer nations curb water use.

"We must take account of how our water footprint is impacting on the rest of the world," said Professor Roger Falconer, director of the Hydro-Environmental Research Centre at Cardiff University and a member of the report's steering committee.

The term perfect storm was used last year by the UK government's chief scientist, Professor John Beddington, to describe future shortages of energy, food and water.

Forecasts suggest that when the world's population soars beyond 8bn in 20 years time, the global demand for food and energy will jump by 50%, with the need for fresh water rising by 30%.

But developing countries are already using significant proportions of their water to grow food and produce goods for consumption in the West, the report says.

"The burgeoning demand from developed countries is putting severe pressure on areas that are already short of water," said Professor Peter Guthrie, head of the Centre for Sustainable Development at Cambridge University, who chaired the steering group.

The average UK consumer uses about 150 litres per day, the size of a large bath.

Ten times as much is embedded in the British-made goods bought by the average UK consumer; but that represents only about one-third of the total water embedded in all the average consumer's food and goods, with the remainder coming from imports.

The UK is not unique in this - the same pattern is seen in most developed countries.

UK-funded aid projects should have water conservation as a central tenet, the report recommends, while companies should examine their supply chains and reduce the water used in them.

This could lead to difficult questions being asked, such as whether it is right for the UK to import beans and flowers from water-stressed countries such as Kenya.

While growing crops such as these uses water, selling them brings foreign exchange into poor nations.

In the West, the report suggests, concerns over water could eventually lead to goods carrying a label denoting their embedded water content, in the same way as electrical goods now sport information about their energy consumption.

The Engineering the Future alliance includes the Institution of Civil Engineers (ICE), the Royal Academy of Engineering (RAE) and the Chartered Institute of Water and Environmental Management (CIWEM).

They identified a link between fewer sunspots and atmospheric conditions that "block" warm, westerly winds reaching Europe during winter months.

"By recent standards, we have just had what could be called a very cold winter and I wanted to see if this was just another coincidence or statistically robust," said lead author Mike Lockwood, professor of space environment physics at the University of Reading, UK.

Professor Lockwood explained that studies of activity on the Sun, which provides data stretching back over 9,000 years, showed that it tended to "ramp up quite slowly over about a 300-year period, then drop quite quickly over about a 100-year period".

"Europe is particularly susceptible because, firstly, it lies underneath the (northern hemisphere's) jet stream," he explained.

A "blocking" occurs when the jet stream forms an "s" shape over the north-eastern Atlantic, causing the wind to fold back over itself.

"If you haven't got blocking, then the jet stream brings the mild, wet westerly winds to give us the weather we are famous for."

But, he added, if the jet stream is "blocked", and pushed further northwards, then cold, dry winds from the east flow over Europe, resulting in a sharp fall in temperatures.

"This... 'blocking' does seem to be one of the things that can be modulated by solar activity," he said.

Recent studies suggest that when solar activity is low, "blocking" events move eastwards from above north-eastern North America towards Europe, and become more stable.

A prolonged "blocking" during the most recent winter was responsible for the long spell of freezing conditions that gripped Europe.

Written observations from the period of the Maunder Minimum referred to the wind coming from the east during particularly cold winters, which strengthened the team's "blocking" hypothesis.

The way in which solar activity affects the behaviour of blocking episodes is linked to the amount of ultraviolet (UV) emissions being produced by the Sun.

Solar UV heats the stratosphere (20-50km above the surface), particularly the equatorial stratosphere. This results in a temperature gradient, which leads to the formation of high level winds.

Studies have shown that the state of the stratosphere can make a considerable difference to what happens in the troposphere, which is where the jet stream occurs, Professor Lockwood explained.

"There has been some quite simple modelling that indicated that heating the equatorial stratosphere with more UV would actually move the jet streams a little bit, by just a few degrees.

To illustrate the point, he said that while the CET record showed that this winter was the UK's 14th coldest in 160 years, global figures listed it as the fifth warmest.

One of the professor's colleagues at the University of Reading referred to Europe as "blocking central".

"The reason is largely because the jet stream has to come to us over the Atlantic Ocean and it is slowed down when it hits the land in Europe.

"You don't quite have the same combination of circumstances anywhere else in the world that gives you such strong blocking."

While the current decline in solar activity is expected to continue in the coming decades, he cautioned that more frequent "blocking" episodes would not result in Europe being plunged into sub-zero temperatures every winter.

"If we look at the last period of very low solar activity at the end of the 17th Century, we find the coldest winter on record in 1684, but the very next year - when solar activity was still low - saw third warmest winter in the entire 350-year (CET) record."

A number of other meteorological factors also influenced the weather systems over Europe, so a number of parameters had to be met before a "blocking" occurred, he observed.

Responding to the team's findings, Dr Peter Stott, head of climate monitoring and attribution at the UK Met Office, said: "This paper provides some additional evidence that what happens in the stratosphere could be important for climate at the surface."

But he added: "The findings are suggestive of a possible effect but more research is needed to pin down the mechanisms and determine how significant such effects could be for determining the probability of cold winters in the UK.

"At the Met Office, we are already working on research into incorporating better representation of the stratosphere into our seasonal and decadal forecasting models."

But the key phrase is in paragraph three where the author writes: "Create a clear understanding of the CA's [Copenhagen accord's] standing and the importance of operationalising ALL elements."

They noticed its brightness dip for more than a year every few decades and surmised that it was part of a binary system consisting of two objects, where one was invisible.

The second object - the ''companion'' - was assumed to be a smaller star, orbited by a thick disk of dust.

The new images support this theory, showing a geometrically thin, dark, dense but partially translucent cloud passing in front of Epsilon Aurigae.

John Monnier, an associate professor at the University of Michigan's department of astronomy, said the images depicted a system unlike any other known to scientists.

''This really shows that the basic paradigm was right, despite the slim probability,'' he said.

''It kind of blows my mind that we could capture this. There's no other system like this known.

''On top of that, it seems to be in a rare phase of stellar life. And it happens to be so close to us. It's extremely fortuitous.''

The images were produced using the Michigan Infra-Red Combiner (MIRC) instrument which allows astronomers to see the shape and surface characteristics of stars.

A new theory put forward by according to Professor Bill Napier, from the Cardiff University Astrobiology Centre suggests it occurred when the Earth strayed into a dense trail of fragments shed by a large comet.

The impacts would have triggered wildfires covering whole continents, filling the atmosphere with smoke and soot and blotting out the Sun.

What caused a sudden cooling of up to 8C just as the Earth was warming at the end of the last ice age has puzzled scientists.

The change caused glaciers to re-advance and coincided with the rapid extinction of 35 families of North American mammals.

Evidence exists of an extraterrestrial event, such as an asteroid or comet impact.

Experts have found a ''black mat'' of soot a few centimetres thick thought to be left by continental-scale wildfires.

Microscopic ''nanodiamonds'' produced by massive shocks and only found in meteorites or impact craters have also been discovered dating back to the disaster.

These findings led to suggestions that an object from space four kilometres across smashed into the Laurentide ice sheet, which at the time covered what is now Canada and the northern US.

But the likelihood of the Earth being struck by such a large object only 13,000 years ago are a thousand to one against.

Also, a single impact cannot explain the occurrence of such widespread fires.

The fragmenting comet theory is more plausible, according to Professor Bill Napier, from the Cardiff University Astrobiology Centre.

He believes there is ''compelling evidence'' to indicate that such a comet entered the inner solar system between 20,000 and 30,000 years ago and has been breaking apart ever since.

The destruction of the comet has given rise to a number of closely related meteor streams known as the Taurid Complex.

''A large comet has been disintegrating in the near-Earth environment for the past 20,000 to 30,000 years and running into thousands of fragments from this comet is a much more likely event than a single collision,'' said Prof Napier.

His model, published in the journal Monthly Notices of the Royal Astronomical Society, suggests that the ''hailstorm'' would have only lasted about an hour.

It would have caused thousands of impacts, generating global fires and depositing nanodiamonds at the ''extinction boundary'' marking the point in time when many species died out.

One recent impact that may have come from the comet is known as the Tagish Lake meteorite, said Prof Napier.

The object fell on Yukon Territory in Canada in January 2000. It contained the largest amount of nanodiamonds of any meteorite studied so far.