Global Warming & Climate Change: The Phenomenon

[ramonmercado]

Published online: 8 November 2006; | doi:10.1038/news061106-11
Climate warming 'seesaws' between the poles
Antarctic ice-drilling reveals linked cycle of warming and cooling.
Michael Hopkin



Researchers trying to understand sudden, seesawing changes in the Arctic's prehistoric climate have found some answers in an unusual place: buried in the Antarctic ice, half a world away. Their work could help to predict the future consequences of sudden polar warming.

By digging more than 2,500 metres down into the Antarctic ice, climate scientists have shown that changes at one pole influence the other. This 'climate seesaw' moves heat from south to north along the length of the Atlantic Ocean.

Similar studies from Greenland have shown that the Arctic climate can warm by as much as 16 °C in just a few decades. The results from Antarctica confirm a theory that these warming episodes, and their subsequent cooling periods, swing back and forth between the poles.

The theory's confirmation could help climatologists to predict the effects of current and future polar warming, says team member Eric Wolff, of the British Antarctic Survey in Cambridge. "If we are sure that climate change in the past has been caused by ocean circulation, we can gauge what might happen."

Fine detail

Members of the European Project for Ice Coring in Antarctica (EPICA) extracted an ice core from Dronning Maud Land, in the Atlantic sector of Antarctica. Bubbles trapped in the ice preserve traces of the atmosphere — and therefore climate — dating back some 150,000 years.

This is not EPICA's longest record of Antarctic climate — their core from Dome C near Vostok dates back 800,000 years — but it is the most detailed. The rate of snowfall at Dronning Maud was more than double that at Dome C, meaning that the new core has much better resolution, revealing climate shifts over centuries or even decades.

As the Antarctic warms, the ocean currents that carry water away from the continent become stronger. Warm water flows as a surface current to the Arctic. Stronger currents transfer more heat to the North Pole, and cool the South. Cold water flows back southward along the ocean floor.

As the Arctic warms, its ice begins to melt. This adds fresh water to the sea, which disrupts the current, because it is less dense than salt water and therefore means that the diluted cold water sinks less readily.

With the current weakened, the Antarctic retains more of the Sun's heat. This warms the southern oceans, eventually causing the there ice to retreat and allowing water to enter the Atlantic from other oceans, thus strengthening the current again and completing the cycle.

Future trends

The EPICA team deduced the temperature record by studying the oxygen isotopes in the Antarctic core, and found that cold conditions in Greenland tend to be associated with warming in Antarctica, and vice versa. They publish their findings in this week's Nature1.

The poles are warming faster than the rest of the world - Greenland is predicted to warm by another 8 °C by the end of the century, and in recent decades the Antarctic has been warming at three times the global average rate. But it is unlikely that the Gulf Stream will shut down entirely, as in the film The Day After Tomorrow, says Wolff.

During past rapid warming events, ice fields in North America probably melted, he explains. But these no longer exist, so there is less ice available to provide fresh meltwater.

Nevertheless, these prehistoric climate shifts were relatively localized, rather than the worldwide warming being caused by greenhouse gases, Wolff adds. "They were very abrupt," he says. "But they were regional, not global."


References
EPICA Community Members, . Nature, 444 . 195 - 198 (2006). | Article |


Story from [email protected]:
http://news.nature.com//news/2006/061106/061106-11.html

 

[ElishevaBarsabe]

central coastal California update

Update on summer-into-winter in central coastal California:

Changed again! We're in early spring weather now that the date is November 9th. Did have a day of rain, which is normal for November, but now all the clouds have drifted off to drown the State of Washington.

 

[ramonmercado]

Gulf Stream Slowed During Little Ice Age
By Phil Berardelli
ScienceNOW Daily News
29 November 2006

A slowing of the Gulf Stream--the Atlantic Ocean's massive warm-water current--may have been responsible for a minor ice age that occurred between 1200 and 1850 C.E. If true, the finding could have implications for tracking future climate change in the northern hemisphere.
Ocean currents can influence weather on a continental scale. Witness the impact of El Niño, the building up of warm water in the western Pacific Ocean, which causes droughts and severe storms across North and South America. Similar effects can happen with the Gulf Stream, which carries tropical waters from the southeastern United States to Scandinavia--and thereby provides western Europe with a more temperate climate than its latitude would justify. A team of scientists hoped to get a better handle on the Gulf Stream's climatic influence by studying its history during the Little Ice Age. Between 1200 and 1800 C.E., average temperatures in Europe dropped about 4° Celsius.

It turns out that as temperatures chilled in Europe, the Gulf Stream decelerated. The team, led by David Lund, now at the California Institute of Technology, came to this conclusion by analyzing ocean sediment cores going back 1000 years from two widely separated sites in the Florida Straits, where the Gulf Stream originates. In particular, the researchers charted the chemical composition of foraminifera, microscopic creatures whose fossilized shells contain evidence of salinity. From the shells of the forams, as they are called, Lund's team deduced a spike in salinity at the water's surface, suggesting cooler temperatures and a slower current. The team's calculations, reported tomorrow in Nature, indicate the Gulf Stream slowed by about 10% just about the time the Little Ice age began, and resumed its current speed around 1850.

Not everyone is convinced. Some scientists have suggested the core-sample data aren't precise enough. Part of the reason is continuing uncertainty about the entire North Atlantic circulation system itself (ScienceNOW, 17 November). Further skepticism comes from oceanographer Carl Wunsch at MIT in Cambridge, Massachusetts, who thinks the researchers are overinterpreting their data. "There are many problems," he says. For example, it is an "unjustified inference" that a weakened Gulf Stream implies less heat being transported northward, leading to a colder Europe.

http://sciencenow.sciencemag.org/cgi/co ... 006/1129/2

 

[ramonmercado]

Published online: 4 December 2006; | doi:10.1038/news061204-2
Europe's warmest autumn in 500 years
Results hint that Europe may be in for a warm winter.
Quirin Schiermeier



Blooming warm: a late onset of winter can cause horse chestnuts to burst into flower too soon.

Alamy

Do you still have roses in bloom in your English garden? Then you might not be surprised to hear that Europe is experiencing the warmest autumn since Columbus first sailed to America.

Preliminary analysis shows that continental mean temperatures in September and October were 11°C — that's 1.8 °C higher than the long-term average for these months. November was 2.5 °C higher than the average. The results show that 2006 has beaten the 'hottest' autumns of 1772, 1938 and 2000 by about a degree.

Previous research has shown that spring seems to be coming earlier around the world (see 'Warming planet shifts life north and early'). But autumn climate trends have been generally less well investigated.

That's partly because warm autumns pose less stress on plants and animals than do temperature anomalies in spring, says Annette Menzel, a phenologist at the Technical University of Munich, Germany. But warm autumns come with their own problems.

Some flowering trees, such as horse chestnuts, may spring into blossom before winter comes, causing problems later in the year. And butterflies and other animals may face trouble if they miss the signal to reduce their activity for the winter. A disruption in the usual pattern between temperature and food availability can cause starvation, Menzel says.

History lesson

Finding data to support seasonal trends can be tricky, however. The instrumental record doesn't date back much further than the onset of the twentieth century.

To get around this, Elena Xoplaki, a climate historian at the University of Bern in Switzerland, has looked at historic sources in Europe going back to the 1500s, such as weather observations recorded by monks, doctors and scholars1.

She has now updated her reconstruction with the latest temperature data from NASA's Goddard Institute for Space Studies. The unpublished study reveals that the past three months have been uniquely warm in the context of the past half millennium, even when the uncertainties related to the historic data are taken into account.

"Exceptionally warm autumns in one region or another wouldn't be so telling," says Juerg Luterbacher, a climatologist at the University of Bern. "But the signal is consistent over the whole European land mass, from Iceland to Greece."

Going up

The change matches a trend. Autumn temperatures in Europe have been rising by about 0.45 °C per decade over the past three decades. The new data show that the past 30 years has been the warmest such period on record, and the past 10 years has been the warmest decade.

The strongest warming has been observed over the British Isles and Scandinavia.

NASA data show an even more extreme autumn temperature anomaly for parts of the Arctic. By contrast, large parts of the United States have been below average (see map). These data only go back to the 1950s.




Hot times: NASA data shows that Europe is abnormally warm, the United States mainly cool.

NASA

Cause and effect

Weather is in essence a random phenomenon. So extreme anomalies during a single season, such as the European summer heat wave of 2003 or this warm autumn of 2006, can't be pinned to a single cause. However, the autumn warming trend over the past few decades does strongly point to a significant human influence, says Luterbacher.

So what can we expect next? Xoplaki and Luterbacher have also looked at what winters were like after the 30 warmest autumns in their data set. They found that Decembers and Februaries were generally warmer than the 1971-2000 European average, whereas Januaries were slightly cooler.

Seasonal climate forecasts by the British Met Office and the International Research Institute for Climate and Society predict a slightly higher probability of warm rather than cold winter conditions over parts of Europe this year. However, cautions Lutenbacher, the skill of seasonal forecasts is low, and uncertainties rather large.


References
Xoplaki E., et al. Geophysical Research Letters, 32 . L15713 (2005).




Story from [email protected]:
http://news.nature.com//news/2006/061204/061204-2.html

 

[ramonmercado]

Bewilderment As Russian Winter Shrivels In Face Of Global Warming

Picture taken 13 December 2006 shows the St. Basil Cathedral with decorated Christmas Tree at the Red Square in Moscow. Russia's capital, renowned for its trademark frosty winters, started the calendar winter with the warmest day recorded in December, the state weather monitoring unit said. Photo courtesy AFP.
by Sebastian Smith
Moscow (AFP) Dec 14, 2006
There is not quite the drama of a Florida hurricane, or the poignancy of stranded polar bears, but Moscow babushka Larisa Bilik is struggling to sell her wool socks -- and global warming, experts say, is also to blame. The warmest November-December since records began has put Russia's fearsome winter on the back foot.
Mushrooms are sprouting outside Moscow, bears are unable to hibernate, and Bilik, who looks older than her 53 years, is having trouble attracting customers to her stall in the city centre, where she hawks thick socks, slippers and fake fur vests.

"When it's cold, they buy, when it's warm they don't," she says, gold teeth flashing against the gloomy, almost permanent twilight that has oppressed sunless -- and snowless -- Moscow for several weeks.

Gennady Yeliseyev, deputy director of the state's weather service, the Gidrometeocentre, said that since November 20 Russia has experienced the warmest temperatures since records began in the 1870s.

"Average temperatures for the first 10 days of December are minus five degrees Celsius (23 degrees Fahrenheit) and the current abnormalities range as high as plus 10 degrees Celsius (50 Fahrenheit)," he said. "This is the weather we'd normally have in late October."

Scientists here believe Russia has fallen victim to the phenomenon of global warming already blamed for turning European ski resorts into grass meadows, driving exotic fish to British coasts, and whipping up ever more destructive natural disasters.

"The obvious explanation is that very powerful cyclones are forming over the north Atlantic and moving toward the Barents Sea," Yeliseyev said. "But there is also general change to a warmer climate and you cannot deny a link to the greenhouse effect."

Leading weather expert Alexander Bedritskovo said that climate change in Russia is "reality."

Although temperatures will inevitably drop -- wet snow could start falling in Moscow this week, according to forecasters -- weird things are already happening in a country synonymous with harsh, long winters.

In far away Siberia, the ice has begun to melt and break up along a 155-mile (250-kilometre) stretch of the great river Yenise.

At the Moscow zoo, warm temperatures are prompting birds into the love making usually reserved for spring, while the brown bear couple Mushir and Rosa are grumpily insomniac as they wait for snow and hibernation.

"His mood is worse, but she's calmer," zoo spokeswoman Yelena Mendosa said. "She's a female and she deals with his moodiness because she loves him."

Human inhabitants of the capital find the lack of snow a mixed blessing.

"Of course I'm waiting impatiently for winter -- I'm a Russian!" exclaimed economics teacher Nina Babrova, 55, resplendent in one of the few fur hats visible on Moscow's streets.

But joining the huddle of smokers on the pavement outside Soyuz Bank, Vladimir Sharikadze, 20, crossed his fingers that the milder weather would last. "This is great for us smokers. Maybe when winter comes we'll have to give up."

Yekaterina, a 20-year-old student, was also making the most of the phony winter.

While most women are now wrapped in trousers and boots, her legs were clad in nothing but thin tights and a skirt that came well above the knees. "This is easy," she said.

And will she be that brave when the traditional Russian freeze finally strikes? She laughed under her white wool hat.

"You must be crazy!"

Russia

 

[QuaziWashboard]

But what is it that's causing sea levels to rise? Surely it can't just be down to ice melting on land and running into the sea. Surely compaired to the amount of water in all the seas all over the world, the amount of water locked up in ice wouldn't be enough to raise it that much? After all when you look at the Earth, most of it is sea already and what little land there is, only a small amount of it contains ice. Is there any possability that the sea is overpopulated with life and displacing itself? If we could remove all life from the sea (purely a hypothetical thought I assure you) would it make a dramatic difference to sea levels?

 

[OneWingedBird]

this is like something from a disaster movie, an 'iceburg' bigger than Manhattan!

Huge Arctic ice break discovered

Ellesmere island is about 800km (500 miles) from the North Pole
Scientists have discovered that an enormous ice shelf broke off an island in the Canadian Arctic last year, in what could be sign of global warming.

It is said to be the largest break in 25 years, casting an ice floe with an area of 66 sq km (25 square miles).

It occurred in August 2005 but was only recently detected on satellite images.

The chunk of ice bigger than Manhattan could wreak havoc if it moves into oil drilling regions and shipping lanes next summer, scientists warned.


For something that large to move that quickly is quite amazing
Luke Copland, University of Ottawa

"The Arctic is all frozen up for the winter and it's stuck in the sea ice about 50km (30 miles) off the coast," said Luke Copland, an assistant professor at the University of Ottawa.

"The risk is that next summer, as that sea ice melts, this large ice island can then move itself around off the coast and one potential path for it is to make its way westward toward the Beaufort Sea where there is lots of oil and gas exploration, oil rigs and shipping."

'Quite amazing'

The ice break was initially undetected due to the remoteness of the northern coast of Ellesmere island, which is about 800km (500 miles) from the North Pole.



Satellite images showed the 15km (9mile) crack, then the ice floating about 1km (0.6 miles) from the coast within about an hour, said Mr Copland, a specialist in glaciers and ice masses.

"You could stand at one edge and not see the other side, and for something that large to move that quickly is quite amazing," he said.

Mr Copland said a combination of low accumulations of sea ice around the edges of the ice mass, as well as the Arctic's warmest temperatures on record, contributed to the break.

The region was 3C (5.4F) above average in the summer of 2005, he said.

Ice shelves in Canada's far north have shrunk by as much as 90% since 1906.

"It's hard to tie one event to climate change, but when you look at the longer-term trend, the bigger picture, we've lost a lot of ice shelves on northern Ellesmere in the past century.

"This is that continuing and this is the biggest one in the last 25 years," he said.

http://news.bbc.co.uk/1/hi/sci/tech/6218333.stm

 

[eburacum]

But what is it that's causing sea levels to rise? Surely it can't just be down to ice melting on land and running into the sea. Surely compared to the amount of water in all the seas all over the world, the amount of water locked up in ice wouldn't be enough to raise it that much? After all when you look at the Earth, most of it is sea already and what little land there is, only a small amount of it contains ice.

The amount of ice on land is quite well known; the sea level rises which are predicted are based on that ice melting (the sea-ice of course doesn't affect the sea level, as it is floating).
If all the ice on Greenland and other icy parts of the Northern Hemisphere were to melt, the sea levels would rise about 10 metres. If all the ice in Antarctica were to melt as well, the sea levels world wide would rise about 70 metres in total. Sea level changes of this magnitude occur fairly regularly at the beginning and end of each ice age; the difference is that we are now in an interglacial, and sea levels generally don't rise much higher than today's levels in an interglacial. So we are heading into unknown territory.

Is there any possibility that the sea is overpopulated with life and displacing itself? If we could remove all life from the sea (purely a hypothetical thought I assure you) would it make a dramatic difference to sea levels?

Very interesting idea, and worth investigating. The mass of all sea-life is mostly made up of water, and that water comes from the sea, so there would be no change in the sea-level due to the water content of the biomass. But phytoplankton fixes carbon from the atmosphere, so the mass of the sea plus the sea-life is greater than just the sea alone. The total biomass would contribute to a slight elevation in sea-levels; that is right; but the biomass has always been there, so we are essentially measuring the sea+biomass level, and always have been. In recent years there is some indication the the mass of phytoplankton has gone down, so it seems that the biomass can't be held responsible for sea-level rises.

 

[QuaziWashboard]

Is there any possibility that the sea is overpopulated with life and displacing itself? If we could remove all life from the sea (purely a hypothetical thought I assure you) would it make a dramatic difference to sea levels?

Very interesting idea, and worth investigating. The mass of all sea-life is mostly made up of water, and that water comes from the sea, so there would be no change in the sea-level due to the water content of the biomass. But phytoplankton fixes carbon from the atmosphere, so the mass of the sea plus the sea-life is greater than just the sea alone. The total biomass would contribute to a slight elevation in sea-levels; that is right; but the biomass has always been there, so we are essentially measuring the sea+biomass level, and always have been. In recent years there is some indication the the mass of phytoplankton has gone down, so it seems that the biomass can't be held responsible for sea-level rises.

So there is currently more ice-mass on land than biomass in the sea?

What happens if we just remove all the sponges? Does the sea level go up or down?

 

[TinFinger]

a quick question but...


wouldnt the amount of ppl who cook dinners and heat there houses contribute to global warming

just think the amount of gas,coal,nuclear,wind,wave,etc that all gets converted to heat by people
these sorces wouldnt have caused any heat at all mostly,so isnt it prudent to take them into consideration

would be ironic if humans were cooking themselves whilst well cooking


lol

 

[GNC]

Not if they're having a nice salad.

 

[ramonmercado]

Record Temperatures Across Himalayans Spark Climate Change Fears

Northern India Cold Snap Toll Now 57
Lucknow (AFP) India, Jan 7 - The death toll from a cold snap since the start of the month in northern India rose to 57 Sunday as 13 more people died over the weekend, officials said. "The toll in the state has gone up to 44," senior medical official Ramesh Mohan Upadhaya told AFP, referring to northern Uttar Pradesh, of which Lucknow is the capital. Eleven deaths were reported from neighbouring Bihar state in the same period, the Press Trust of India said quoting unnamed sources. Two more deaths were reported from Haryana and West Bengal states. The weather office predicted a further fall in temperatures, which plunged below zero degree celsius (32 degree Fahrenheit) in a few places in northern India.
Officials in Uttar Pradesh have ordered bonfires to be lit in public places so that poor people can warm themselves. Each year scores of homeless people in India die due to cold because of inadequate food and clothing. Almost 200 people froze to death in the country's north last winter.

by Staff Writers
Beijing (AFP) Jan 07, 2007
Temperatures in rugged Tibet have hit record highs in recent days, China's state press said Sunday, as a scientific survey warned of the impact of global warming in the Himalayan region. Friday's temperature in the Qamdo area of eastern Tibet was 21.8 degrees Celsius (71 degrees Fahrenheit), 1.7 degrees higher than the previous record set for the same day in 1996, Xinhua news agency reported.
In Dengqen county, also in eastern Tibet, the mercury reached 16.6 degrees Celsius on Thursday, 2.5 degrees higher than the previous record for the same day set in 2001, it said.

Eight other places across the region also recorded record-breaking daily temperatures over the past few days, it added.

Meteorological data in the Himalayan region began to be collected in 1970.

China's Tibet plateau, seen as a barometer of world climate conditions, is experiencing accelerating glacial melt and other ecological change, the leading People's Daily reported Friday.

The mountainous region's glaciers have been melting at an average rate of 131.4 square kilometers (50 square miles) per year over the past 30 years, the paper said, citing a recent geological study.

Researchers who conducted the survey said that even if global warming did not worsen, the area's glaciers would be reduced by nearly a third by 2050 and up to half by 2090, at the current rate.

The survey, conducted by the Remote Sensing Department of the China Aero Geophysical Survey, also found a rapidly rising snow line, shrinking wetlands, and increased desertification compared with 30 years ago, the paper said.

These problems will worsen as the glacial melt -- which has accelerated in recent years -- continues, further depleting the area's water resources, the researchers predicted.

The Tibet plateau, which includes the Chinese portion of the Himalayas, accounts for nearly one quarter of China's landmass, stretching from Tibet to the adjacent provinces of Qinghai, Sichuan and Yunnan.

A separate national assessment released last week on the impact of climate change said temperatures in China would rise significantly in coming decades, water shortages would worsen, and extreme weather events would intensify.

earlier related report
Tibetan Glacial Melt Accelerating
Beijing (AFP) Jan 5 - China's rugged Tibet plateau, seen as a sensitive barometer of world climate conditions, is experiencing accelerating glacial melt and other ecological change, state media reported on Friday. The mountainous region's glaciers have been melting at an average rate of 131.4 square kilometres (50 square miles) per year over the past 30 years, the People's Daily said, citing a geological study of the region.

Researchers who conducted the survey said that even if global warming did not worsen, the area's glaciers would be reduced by nearly a third by 2050, and up to half by 2090, at the current rate.

The survey, conducted by the Remote Sensing Department of the China Aero Geophysical Survey, also found a rapidly rising snow line, shrinking wetlands, and increased desertification compared with 30 years ago, the paper said.

These problems will worsen as the glacial melt -- which has accelerated in recent years -- continues, further depleting the area's water resources, the researchers predicted.

The plateau, which includes the Chinese portion of the Himalayas, accounts for nearly one quarter of China's landmass, stretching from Tibet to the adjacent provinces of Qinghai, Sichuan and Yunnan.

The snow line on the edges of the plateau had retreated an average 100 to 150 metres, but up to 350 metres in some areas, while wetlands had been reduced by 10 percent, the report said. A separate national assessment of the impact of global climate change released last week said temperatures in China would rise significantly in coming decades, water shortages would worsen, and extreme weather events would intensify.

Himalayas

 

[QuaziWashboard]

I've recently heard that apparently kangaroos have a bacteria in their stomach that does something that stops them farting and it's being looked into in the hope that if introduced to a cow's stomach it would do the same and hopefully have an effect on global warming. Has anyone else heard of this?

 

[Rubyait]

2100: A world of wild weather

Think back to the hottest summer you can remember. Now imagine a summer like that every year. For those of us who are still around by the end of the 21st century, this is what we can expect, according to a new index that maps the different ways that climate change will hit different parts of the world. The map reveals how much more frequent extreme climate events, such as heatwaves and floods, will be by 2100 compared with the late 20th century. It is the first to show how global warming will combine with natural variations in the climate to affect our planet.

"We hope it will help policy-makers gain a quick overview of the scientific facts without getting lost in the detail," says Michèle Bättig of the Swiss Federal Institute of Technology in Zurich, who created the index with colleagues after talking to delegates at the 2005 UN Climate Change Conference in Montreal, Canada. The index allows anyone to compare the severity of the predicted effect of climate change on a chunk of the Amazon rainforest, for example, with its effect on a corner of Antarctica.

The results are presented on a global map (see top image), in which the areas experiencing the greatest changes are shown in the darkest shades. Swathes of the tropics and high latitudes are coloured a foreboding brown, signifying the most marked changes.

Perhaps the most startling feature is how few areas remain unscathed. "This reinforces what much of the piecemeal climate science is telling us - that many places will face severe challenges," says Neil Adger of the UK's Tyndall Centre for Climate Change Research at the University of East Anglia in Norwich, Norfolk. In the coming decades people in these areas could find it difficult or impossible to adapt to the changed conditions, he adds.

For many parts of the world it seems this trend is already under way. Climate scientists announced last week that 2006 has been the hottest year on record for the US, topping nine years of almost continuous rises. Meanwhile, Europe experienced severe heatwaves in both 2003 and 2006, and for the UK 2006 was the warmest year since records began. Nor does it look as if the mercury is going to stop rising. In an energy technology outlook study published last week, the European Commission warns of stark changes for EU countries over the coming century, including shrinking forests, floods, drought and the drying out of fertile land - unless radical steps are taken to combat climate change.

Yet in a global context, even these dramatic changes seem relatively modest. On Bättig's climate change index map Europe, the US and Australia are coloured in shades of yellow and orange, putting them at around 6 or 7 on the scale. Parts of South America's Amazon rainforest and Africa's Congo basin fare much worse, with a predicted climate change index of around 11 (Geophysical Research Letters, DOI: 10.1029/2006GL028159).

The index was calculated from nine separate indicators of climate change. These included years that are hot, dry or wet overall, and also those in which the months of June, July and August, or December, January and February, would be extremely warm, dry or wet. Bättig and her colleagues divided the world into squares measuring 375 by 375 kilometres, and for each indicator they identified the extreme climate events that in the period 1961 to 1990 would have been expected to occur in 1 year in 20.

Using three different global climate models, each based on a mid-range forecast for greenhouse gas emissions, they computed the likely change in frequency of these extreme events during the period 2071 to 2100. The changes were then weighted to provide a single number between 0 and 19 for each grid square. A value of 0 equates to all nine climate indicators remaining as 1-in-20-year events, whereas a value of 19 equates to all climate indicators becoming annual events.

"It is a very striking graphic," says Chris West, director of the UK Climate Impacts Programme at the University of Oxford. While other climate change indices have compared changes in average temperature or precipitation, this is the first global index based on climate extremes. "It focuses the debate on the big events we ought to be worrying about," says Tom Downing of the Stockholm Environment Institute and author of The Atlas of Climate Change.

The new index has its limitations. "Places that become hotter will face different problems to places that become wetter, but the index implies that they have the same level of risk," Downing says. Bättig has addressed this problem with separate maps for each climate indicator. The first of these, representing additional hottest years, shows the world in an ominous deep red (see Map). When it comes to overall temperature, 1-in-20-year temperatures are set to become annual events by the end of this century. "What we take now as a surprise will be normal", says Downing.

Meanwhile, Antarctica and the Arctic can expect exceedingly wet years to become 13 times more likely, while tropical regions like the Amazon rainforest and the Congo basin will suffer droughts around 13 times more frequently (see Map). Rainfall in places in the middle, like Australia and the southern US, is expected to remain fairly close to what it is now.


From issue 2587 of New Scientist magazine, 18 January 2007, page 6-7
Where natural disasters now take their toll
Climate change is not the same as climate impact, as changes in temperature and precipitation will affect people in some regions far more than others. For example, sub-Saharan Africa is a drought hotspot, while south and south-east Asia are vulnerable to storms and flooding. Any changes in climate here could affect people more severely than, say, those in Europe.

Art Lerner-Lam and colleagues from Columbia University in Palisades, New York, have sketched out which natural disasters pose the greatest threat to life on a global map of their own (see bottom image, right). They produced their map by combining data on hazard frequency and intensity from the recent past with population density, GDP and geographical factors such as land use. This has already influenced organisations such as the World Bank in deciding which regions should be prioritised for emergency lending.

The next step will be to overlay the extent of climate change, as revealed by Bättig's index for example, and see how this affects the frequency and severity of future hazards. "We are working on this right now," says Lerner-Lam.

http://environment.newscientist.com/art ... ather.html

 

[Pietro_Mercurios]

Every day, it's a'getting closer,
Going faster, than a rollercoaster

Link:
Surge in carbon levels raises fears of runaway warming
David Adam Environment correspondent. Friday January 19, 2007. The Guardian

· Figures show higher than expected rise in CO2
· Scientists warn earth may be absorbing less gas

Carbon dioxide is accumulating in the atmosphere much faster than scientists expected, raising fears that humankind may have less time to tackle climate change than previously thought.

New figures from dozens of measuring stations across the world reveal that concentrations of CO2, the main greenhouse gas, rose at record levels during 2006 - the fourth year in the last five to show a sharp increase. Experts are puzzled because the spike, which follows decades of more modest annual rises, does not appear to match the pattern of steady increases in human emissions.

At its most far reaching, the finding could indicate that global temperatures are making forests, soils and oceans less able to absorb carbon dioxide - a shift that would make it harder to tackle global warming. Such a shift would worsen even the gloomy predictions of the Stern Review which warned that we had little over a decade to tackle rising emissions to avoid the worst effects of climate change.

David Hofmann of the US National Oceanic and Atmospheric Administration (Noaa), which published the figures, said: "Over this last decade the growth rates in carbon dioxide have been higher. I don't think we can plausibly say what's causing it. It's something we're going to look at."

Peter Cox, a climate change expert at Exeter University, said: " The concern is that climate change itself will affect the ability of the land to absorb our emissions." At the moment around half of human carbon emissions are reabsorbed by nature but the fear among scientists is that increasing temperatures will work to reduce this effect.

Professor Cox added: "It means our emissions would have a progressively bigger impact on climate change because more of them will remain in the air. It accelerates the rate of change, so we get it sooner and we get it harder."

Carbon dioxide concentration in the atmosphere is measured in parts per million (ppm). From 1970 to 2000 that concentration rose by about 1.5ppm each year, as human activities sent more of the gas into the atmosphere. But according to the latest figures, last year saw a rise of 2.6ppm. And 2006 was not alone. A series of similar jumps in recent years means the carbon dioxide level has risen by an average 2.2ppm each year since 2001.

Above-average annual rises in carbon dioxide levels have been explained by natural events such as the El Niño weather pattern, centred on the Pacific Ocean. But the last El Niño was in 1998, when it resulted in a record annual increase in carbon dioxide of 2.9ppm. If the current trend continues, this year's predicted El Niño could see the annual rise in carbon dioxide pass the 3ppm level for the first time.

Prof Cox said that an increase in forest fires, heatwaves across Europe and the Amazon drought of 2005 could have helped to drive up carbon dioxide levels. Such events are predicted to become more frequent with rising global temperatures. He admitted "the jury is still out" on whether the recent spike is evidence of a significant change, although some computer models predict that the Earth will start to absorb less carbon dioxide some time this decade.

"Over the past few years carbon dioxide has been going up faster than we would expect, based on the rate that emissions are increasing," Prof Cox said.

Figures presented to a recent UN climate conference in Nairobi showed that carbon dioxide emissions produced by the worldwide burning of fossil fuels increased by 3.2% from 2000 to 2005.

From 1990 to 1999 the emissions increase was 0.8%. But other experts think rising emissions could yet account for the anomaly. Pieter Tans of Noaa cited contrasting figures from the US Department of Energy, which show much sharper annual emissions increases, up to 4.5% in recent years. The Intergovernmental Panel on Climate Change is expected to announce more robust emissions data when it reports next month.

 

[ramonmercado]

Drumlin formed in a blink of geological time
11:02 26 January 2007
NewScientist.com news service
Catherine Brahic
Researchers camp out on the Rutford Ice Stream in Antarctica (Image: British Antarctic Survey) Graph showing changes in the outline of the bed of the Rutford Ice Stream between 1991and 1997 (top graph) and between 1997 and 2004 (bottom graph); a considerable amount of erosion was noted in 1997, and a large lump of sediment appeared in 2004 (Image: Geology)Advertisement
A new study threatens to overturn our understanding of how glaciers deposit whale-shaped hills known as drumlins. The findings could have implications for the computer models used to predict glacier flow and subsequent changes in sea-level.

Andy Smith of the British Antarctic Survey and his colleagues are the first to see a drumlin during formation. They have visited the same spot of the Rutford Ice Stream in Antarctica three times since 1991. Each time, they have mapped the shape of the glacier bed, which lies 2000 metres under the surface of the ice.

The maps are created by sinking explosives in the ice and recording the echo of the detonation after it is reflected off the riverbed. The time it takes for the echo to return to the surface reveals how deep the riverbed is, while the researchers can judge how hard it is from the echo's quality and loudness.

The most recent data, from 2004, revealed a big surprise: a large lump of sediment, 10 metres high and 100 m wide that "plainly wasn't there last time we looked" in 1997, says Smith's colleague David Vaughan, also at BAS.

"This is the first time anyone has observed a drumlin actually forming under the ice," says Smith. Researchers generally assume that ancient drumlins, which are common in the US, the Alps, Ireland, Finland and Patagonia, grew slowly as sediments set in motion by a meltwater river gradually accumulated underneath the ice.

Wholesale movement
However, the new work shows that this is not necessarily the case, says Vaughan: "What is surprising is that big lumps of sediment are being moved around wholesale rather than being slowly accumulated."

He says the mass of sediment seems like it is encased in the underside of the ice sheet and being dragged along as the glacier moves towards the sea. And it could be bigger yet – the researchers do not know how long it is.

Direct observations of activity under ice sheets are rare. Those from the Rutford Ice Stream suggest that theories about the movement of ice sheets that have been extrapolated from the shape, size, age and location of ancient drumlins could be flawed.

"Predicting the future of the world’s ice masses and their impact on sea level requires an understanding of subglacial processes," write the authors in Geology.

The findings are a reminder, says Vaughan, that "all the theories and supposed understanding that we've got about drumlins come from studying relic drumlins that were formed 10,000 years ago and have undergone changes since".

Journal reference: Geology (vol 35, p127)

Related Articles
Hidden Antarctica: What lies beneath
http://environment.newscientist.com/art ... 225801.800
01 December 2006
Greenland ice cap may be melting at triple speed
http://environment.newscientist.com/article/dn9717
10 August 2006
Giant crater may lie under Antarctic ice
http://environment.newscientist.com/article/dn9268
02 June 2006
Weblinks
British Antarctic Survey
http://www.antarctica.ac.uk/
Drumlins, Wikipedia
http://en.wikipedia.org/wiki/Drumlin


http://environment.newscientist.com/art ... -time.html

 

[rynner2]

Ice island the size of London threatens rigs
A two-million-ton iceberg will be on the move in the Arctic this summer thanks to global warming, putting busy shipping lanes in danger
By Jonathan Owen
Published: 28 January 2007

An enormous iceberg the size of central London is causing alarm among scientists, who predict that it could be on the move in a matter of months, posing a potential threat to shipping and oil rigs in Arctic waters.

The two-million-ton, 25-square-mile block of ice is part of the Ayles ice shelf. Its existence only recently came to light thanks to satellite images from Nasa. Lying 30 miles off Canada's Ellesmere Island, it will be on the move in the summer, as temperatures rise and break up the surrounding pack ice.

"The potential issue here is that the ice island could go into the oil rigs in the Beaufort Sea," said Dr Luke Copland, a specialist in ice masses based at the University of Ottawa. "This hasn't happened in the past, but it could happen."

The ice could move several hundred miles over the summer, taking it closer to busy shipping routes for oil and gas. "If it ever came on a collision course with an oil rig, it is unlikely that we would be able to do much to stop it," said Dr Copland. "Maybe you would have to consider aerial bombardment to break it up, or use lots of tugs to try and move it, but it would be a lot of ice to move."

Tugs are already on permanent standby along Canada's coastline to lasso stray icebergs and tow them away from busy shipping routes, but researchers say controlling the main mass, dubbed "ice island", would be a completely different proposition.

Scientists blame global warming. "This is the most dramatic climate-related event we've seen in recent times in the high Arctic," said Professor Warwick Vincent of Laval University in Quebec. "We think it was associated with record warm temperatures and record minimum sea ice. Of course these days, every year sets a new record. The ice island has already moved 50km [30 miles] to the west, and could eventually end up in shipping and oil-exploration areas."

Scientists in Canada and the US have stepped up their monitoring of the ice as they attempt to predict where and when it is likely to go next. A team of researchers will visit the ice island in March, before it starts to move in the summer. It is thought most likely to follow a clockwise current in the Arctic Ocean, known as the Beaufort Gyre, that could see it reach the eastern coast of Greenland in 10 years. The warmer waters of the Atlantic would prevent it from travelling further south.

Climate change is altering the region's landscape. The Ayles ice shelf, thought to be 4,000 years old, was one of just six remaining on Ellesmere Island, Canada's most northern landmass. The ice shelves there have shrunk by up to 90 per cent in the past century - a loss of 3,500 square miles of ice, along with an unknown number of life forms.

Experts now claim the next 10 years could see massive changes in sea ice in the region. Researchers from the Canadian Ice Service have already seen average temperatures for the past few months 7C higher than they would normally expect.

"There is a lot more fracturing of the sea ice than we'd normally see at this time of year," said Dr Copland. "When you look at Arctic sea ice, it has been reducing dramatically over the past 30 years and it is hard to explain why that would happen without invoking climate warming."

http://news.independent.co.uk/environme ... 192978.ece

 

[rynner2]

Global Warming: The vicious circle
By Steve Connor, Science Editor
Published: 29 January 2007

The effects of man-made emissions of carbon dioxide are being felt on every inhabited continent in the world with very different parts of the climate now visibly responding to human activity.

These are among the main findings of the most intensive study of climate change by 2,000 of the world's leading climate scientists. They conclude that there is now little doubt that human activity is changing the face of the planet.

In addition to rising surface temperatures around the world, scientists have now linked man-made emissions of greenhouse gases to significant increases in ocean temperatures, rises in sea levels and the dramatic melting of Arctic sea ice over the past 35 years.

A draft copy of the fourth report of the Intergovernmental Panel on Climate Change (IPCC) says that global temperature rises this century of between 2C and 4.5C are almost inevitable. Ominously, however, it also says that much higher increases of 6C "or more" cannot be ruled out.

The final version of the IPCC's latest report is to be published on Friday but a draft copy, seen by The Independent, makes it clear that climate change could be far worse than previously thought because of potentially disastrous "positive" feedbacks which could accelerate rising temperatures.

A warmer world is increasing evaporation from the oceans causing atmospheric concentrations of water vapour, a powerful greenhouse agent, to have increased by 4 per cent over the sea since 1970. Water vapour in the atmosphere exacerbates the greenhouse effect. This is the largest positive feedback identified in the report, which details for the first time the IPCC's concern over the uncertainties - and dangers - of feedback cycles that may quickly accelerate climate change.

All the climate models used by the IPCC also found that rising global temperatures will erode the planet's natural ability to absorb man-made CO2. This could lead to CO2 concentrations in the atmosphere rising by a further 44 per cent, causing global average temperatures to increase by an additional 1.2C by 2100.

The IPCC's Fourth Assessment Report will go further than any of its three previous reports in linking the clear signs of global climate change with increases in man-made emissions of CO2 and other greenhouse gases since the start of the Industrial Revolution.

"Confidence in the assessment of the human contributions to recent climate change has increased considerably since the TAR [Third Assessment Report]," says the draft report. This is due to the stronger signs of climate change emerging from longer and more detailed records and scientific observations, it says.

The "anthropogenic signal" - the visible signs of human influence on the climate - has now emerged not just in global average surface temperatures, but in global ocean temperatures and ocean heat content, temperature extremes on the land and the rapidly diminishing Arctic sea ice. "Anthropogenic warming of the climate system is widespread and can be detected in temperature observations taken at the surface, in the free atmosphere and in the oceans," the draft report says. "It is highly likely [greater than 95 per cent probability] that the warming observed during the past half century cannot be explained without external forcing [human activity]."

The report adds that global warming over the past 50 years would have been worse had it not been for the counterbalancing influence of man-made emissions of aerosol pollutants, tiny airborne particles that reflect sunlight to cause atmospheric cooling. "Without the cooling effect of atmospheric aerosols, it is likely that greenhouse gases alone would have caused more global mean temperature rise than that observed during the last 50 years," the draft report says.

"The hypothetical removal from the atmosphere of the entire current burden of anthropogenic sulphate aerosol particles would produce a rapid increase of about 0.8C within a decade or two in the globally averaged temperature."

The IPCC says that over the coming century we are likely to see big changes to the Earth's climate system. These include:

* Heat waves, such as the one that affected southern Europe in summer 2003, are expected to be more intense, longer-lasting and more frequent.

* Tropical storms and hurricanes are likely to be stronger, with increased rainfall and higher storm surges flooding coastlines.

* The Arctic is likely to become ice free in the summer, and there will be continued melting of mountain glaciers, ice caps and ice sheets.

* Sea levels will rise significantly even if levels of CO2 are stabilised. By 2100 sea levels could be 0.43 metres higher on average than present, and by 2300 they could be up to 0.8 metres higher.

The IPCC also finally nails the canard of the climate sceptics who argue that global warming is a myth or the result of natural climate variability; natural factors alone cannot account for the observed warming, the IPCC says. "These changes took place at a time when non-anthropogenic forcing factors (i.e. the sum of solar and volcanic forcing) would be expected to have produced cooling, not warming.

"There is increased confidence that natural internal variability cannot account for the observed changes, due in part to improved studies demonstrating that the warming occurred in both oceans and atmosphere, together with observed ice mass losses."

The report, the first draft of which was formulated last year, will be made public on Friday in Paris.

Key findings of the IPCC's fourth assessment report

* Global temperatures continue to rise with 11 of the 12 warmest years since 1850 occurring since 1995. Computer models suggest a further rise of about 3C by 2100, with a 6C rise a distant possibility

* It is virtually certain (there is more than a 99 per cent probability) that carbon dioxide levels and global warming is far above the range of natural variability over the past 650,000 years

* It is virtually certain that human activity has played the dominant role in causing the increase of greenhouse gases over the past 250 years

* Man-made emissions of atmospheric aerosol pollutants have tended to counteract global warming, which otherwise would have been significantly worse

* The net effect of human activities over the past 250 years has very likely exerted a warming influence on the climate

* It is likely that human activity is also responsible for other observed changes to the Earth's climate system, such as ocean warming and the melting of the Arctic sea ice

* Sea levels will continue to rise in the 21st Century because of the thermal expansion of the oceans and loss of land ice

* The projected warming of the climate due to increases in carbon dioxide during the 21st Century is likely to cause the total melting of the Greenland ice sheet during the next 1,000 years, according to some computer forecasting models

* The warm Gulf Stream of the North Atlantic is likely to slow down during the 21st Century because of global warming and the melting of the freshwater locked up in the Greenland ice sheet. But no models predict the collapse of that warm current by 2100.

http://news.independent.co.uk/environme ... 193672.ece

 

[Anonymous]

What actually is causing global warming?

I've read stories about CO2, about the Sun's core getting hot and 'cold' every 100,000 years, pole reversal, loads of stuff.

Seems like there are as many explanations for global warming as there are for dinosaur extinction.

What is really going on here?

 

[Pietro_Mercurios]

What actually is causing global warming?

I've read stories about CO2, about the Sun's core getting hot and 'cold' every 100,000 years, pole reversal, loads of stuff.

Seems like there are as many explanations for global warming as there are for dinosaur extinction.

What is really going on here?

There are too many people releasing too much fossil carbon into the atmosphere.

Trillions of tons of carbon, that's been stored up steadily over 4 billion years, in solid form, or trapped in the Earth's upper layers, as oil, coal, natural gas, peat, methane hydrates, etc., have been released into the atmosphere in the form of CO2 (carbon dioxide) and CO (carbon monoxide, or methane: several times more potent as a greenhouse gas), etc., in just the last 250 years, as a result of the Industrial Revolution.

The maths are fairly straight forward. The more carbon released as greenhouse gasses, the more heat from the sun is trapped by the Earth's atmosphere, the warmer it gets.

Think of the planet Venus. It's atmosphere is composed of thick clouds of carbonic gasses and the surface temperature is hot enough to melt lead. Of course, we'll drown before we fry.

 

[rynner2]

Trillions of tons of carbon, that's been stored up steadily over 4 billion years, in solid form, or trapped in the Earth's upper layers, as oil, coal, natural gas, peat, methane hydrates, etc., have been released into the atmosphere in the form of CO2 (carbon dioxide) and CO (carbon monoxide, or methane: several times more potent as a greenhouse gas), etc., in just the last 250 years, as a result of the Industrial Revolution.

just to clarify, carbon monoxide is CO,
methane is CH4.

 

[Pietro_Mercurios]

...

just to clarify, carbon monoxide is CO,
methane is CH4.

What rynner said.

 

[QuaziWashboard]

I'm in agreement with coldelephant, and to a cirtain extent, what Mark Mardell says here. We know the earth has natural cycles lasting many thousands of years and with these cycles comes natural change in the natural world.
In my opinion, we should be doing everything we can to stop the unnatural change caused by ourselves but to try and reverse what we have done could be just as harmful.
Because of the unnatural changes, other creatures will have found natural advantages that they maybe wouldn't have otherwise. In other words, they may have been saved from extinction and steered down a slightly different path of evolution that will ensure the survival of their decendants. To suddenly turn the tables on them again just wouldn't seem fair somehow. It'd be like giving a poor man a fortune then taking it away again.
It has to be said, many of todays endangered creatures are endangered because their natural habitat has disappeared, in some cases never to return, so what's the point of breeding programs to restock the wild when there's nowhere for them to go?
Giving one species an advantage subsequently gives another species a disadvantage....and vice versa. The eco-system is such a delecately balanced thing that any change we make in any direction is going to knacker the future of something. So morally, the best thing to do is 'nothing' and let nature take it's natural course from now on, while doing everything we can to ensure the future of our own species (which is after all why we, or any other species, is here) while at the same time making as little change to our surroundings as is feasably possible.

 

[ramonmercado]

From Greenhouse To Icehouse: New Clues On Ancient Climate Shift

"The big fall in temperature can only be explained by a decrease in carbon dioxide (CO2), the principal greenhouse gas, which has natural causes (such as volcanic eruptions) as well as man-made ones."

by Richard Ingham
Paris (AFP) Feb 07, 2007

Nearly 34 million years ago, a plunge in temperatures began to transform Antarctica, then a lush, green continent that for tens of millions of years had been bathed in warmth, into the icy wilderness more familiar to us today. Seafloor evidence taken from around Antarctica testifies to this event, known as the Oligocene glaciation. But it remains shrouded in many mysteries.
While Antarctica gradually froze and thickened into a massive icesheet, what happened in the rest of the world? And, most intriguing of all, why did the great chill happen?

In new studies published on Thursday by Nature, investigators believe they can dispel a bit of the fog surrounding the Oligocene shift, demonstrating that the freeze had a profound impact on climate and biodiversity deep inside the great continents.

Guillaume Dupont-Nivet, of Utrecht University in the Netherlands, led a team that probed layers of sedimentary rock in the Xining basin on the northeastern fringes of the arid Tibetan plateau.

Sedimentary deposits such as these came from lakes that once flooded the region on a rhythmic scale. The researchers constructed a timescale at which this flooding occurred and eventually ended by measuring a minute, residual magnetic signal from particles in the rock.

Earth's magnetic field goes through changes, and each shift can be detected in the polarity of iron particles in rock deposits, providing a calendar of geological history.

Dupont-Nivet found that the drying out of Xining occurred precisely when the Antarctic glaciation began.

That finding is a blow for the leading explanation as to why Asia became arid.

This theory suggests that Asia became drier after the Indian sub-continent collided with the Asian landmass, an impact that drove up the Tibetan plateau and created a "rain shadow" in which heavy precipitation was unable to penetrate beyond the barrier of the Himalayas.

In the continental United States, meanwhile, researchers led by Alessandro Zanazzi of the University of South Carolina measured two stable isotopes of oxygen in teeth enamel and bones of mammal fossils in the northern Great Plans.

These isotopes are indicators of the temperature record at the time the animals lived.

Zanassi's team calculate that over about 400,000 years, the temperature plummeted by 8.2 C (14.75 F), give or take 3.1 C (5.6 F).

That would explain why the fossil records show a dramatic turnover of species during this period. Many species of amphibians, reptiles and gastropods in what is now North America died out during the big chill, but most mammals were unaffected.

The likely reason: cold-blooded species cannot regulate their body temperature but mammals can.

As to the big question -- how did Antarctica's glaciation occur? -- the mainstream idea is tectonic. Antarctica, Australia and South America were glommed together in a supercontinent, which eventually pulled apart.

Antarctica became surrounded by a chill sea that left it climatically isolated, according to this thinking.

But, in a commentary also published by Nature, Gabriel Bowen of Purdue University, Indiana, says that this hypothesis, too, has to be nixed.

For one thing, computer models suggest a change in ocean circulation around Antarctica would warm, rather than cool, the northern continents. And the latest findings prove that the glaciation could not have been a purely local event, but global.

"The early Oligocene was a turning point not just for Antarctica, but for Earth as a whole," says Bowen.

He believes that the big fall in temperature can only be explained by a decrease in carbon dioxide (CO2), the principal greenhouse gas, which has natural causes (such as volcanic eruptions) as well as man-made ones.

Finding out what happened could help understand the current state of the world's climate, which is being driven by man-made warming towards a "potentially ice-free state," believes Bowen.

link!

stu edit - long link quite easily rendered smaller by use of code

 

[Peripart]

It's started snowing again.

 

[Hexebus]

I don't know if it's been posted before, and I apologise if it has, but imho one of the best discussion sites on the net for climate change is here:- http://www.ukweatherworld.co.uk/forum/forums/forum-view.asp?fid=30

There is a real balance between GW and AGW, and many scientists regularly post there.

 

[Rubyait]

Global impact of Asia's pollution

Industrial pollution coming from Asia is having a wider effect on global weather and climate than previously realised, research suggests.

The "Asian haze" of soot is boosting storms in the Pacific, scientists find.

It is also enhancing the growth of large clouds, which play a key role in regulating climate globally.

Writing in the journal Proceedings of the National Academy of Sciences (PNAS), the researchers say impacts may be felt as far away as the Arctic.

"It's a complex picture," observed study leader Renyi Zhang from Texas A&M University in College Station, US.

"But the bottom line is that the aerosols actually enhance convection and increase precipitation over a large domain," he told the BBC News website

Hot water

While clean air legislation has reduced production of industrial aerosols - fine particles of dust, soot and sulphur - in Europe and North America, the opposite trend is seen in Asia.

Here, rapid industrialisation has led to the formation of a pollution haze which is especially marked in winter as coal burning increases.

Sulphur emissions have increased by more than one-third over the last decade.

These aerosols drive cloud formation, as water droplets coalesce around the tiny particles.

When aerosols are abundant, the droplets stay too small to form rain. Under these conditions, clouds may grow bigger and last for longer.

When the clouds are of the type known as deep convective clouds, this means they also transmit more heat from the Earth's surface into the higher atmosphere.

Deep convective clouds play a key role in regulating the global climate; and the role of aerosols in cloud development remains the major uncertainty in forecasting climate change.

Clouding up

In the latest research, Professor Zhang and his colleagues used satellite records to show that the amount of deep convective clouds over the north Pacific has increased.

Coverage for the period 1994-2005 was between 20% and 50% higher than in the preceding decade.

With increased clouds and increased convection came a growth in storminess - the "storm track" - over the ocean.

Computer models suggest that the trends are being driven by Asian aerosol production, rather than by other factors such as changes in ocean temperature.

"The storm track regulates the jet stream," commented Professor Zhang. "And if more heat is being transported from lower to higher latitudes, that is going to have a large effect on the global circulation."

But the link between clouds and aerosols works in the opposite direction too. Clouds transport the tiny particles, and more abundant and persistent clouds will transport them further - even to polar regions, Professor Zhang suggests.

Some studies have suggested that accumulation of these particles is changing the properties of Arctic ice, making it absorb more of the Sun's energy.

This would mean the ice is more prone to melting, as well as reducing the Earth's capacity to reflect solar energy back into space.

http://news.bbc.co.uk/1/hi/sci/tech/6421303.stm

 

[Scunnerlugzz]

I don't care if it was the chairman of Shell himself that discovered the the correlation betwen solar activity and global temperature fits better than the correlation between global temperature and atmospheric CO2.

The FACT that it does should be enough to put the brakes on the CO2 bandwagon by itself. Unfortunately there is no room for that particular inconvenient truth.

Instead of concentrating on the facts people seem to be trying to discredit who discovered them, not really a logical arguement IMHO.

 

[crunchy5]

The thing is, it is undeniable that Co2 among other gasses is what we call a green house gas, that is a FACT, now if the sun is heating up, a position I agree with based upon astronomical observations, our vast increase in the amount of Co2 in the atmosphere at just the wrong time isn't gonna help is it. My biggest worry is that a solar cycle coupled with a man made atmospheric changes could heat the shallow coastal seas by the few degrees necessary to melt the Methane gas hydrates which would cause the runaway global warming that supposedly brought about the Permian extinctions.

 

[Pietro_Mercurios]

The thing is, it is undeniable that Co2 among other gasses is what we call a green house gas, that is a FACT, now if the sun is heating up, a position I agree with based upon astronomical observations, our vast increase in the amount of Co2 in the atmosphere at just the wrong time isn't gonna help is it. My biggest worry is that a solar cycle coupled with a man made atmospheric changes could heat the shallow coastal seas by the few degrees necessary to melt the Methane gas hydrates which would cause the runaway global warming that supposedly brought about the Permian extinctions.

Yes. Not either the Sun getting brighter and the Earth getting warmer, or the Greenhouse Effect, but both.

Double the fun. :splat: