Yahoo News 13 Nov 08;
BEIJING (AFP) – Enormous brown clouds of pollution hanging over Asia are killing hundreds of thousands of people, melting glaciers, changing weather patterns and damaging crops, the United Nations said Thursday.
Car traffic, factory emissions and indoor cooking are among the culprits for the "Atmospheric Brown Clouds", which are up to three kilometres (1.8 miles) thick, according the UN's Environment Programme (UNEP).
Releasing a landmark report on the phenomenon, the UNEP said getting rid of the clouds could help ease many environmental problems in Asia.
"The Atmospheric Brown Cloud is both complex and in need of a great deal more attention," UNEP executive director Achim Steiner told reporters.
Unlike greenhouse gas emissions blamed for global warming, which take decades or longer to disperse, the clouds would disappear in a matter of weeks if the sources of the problem ceased to pollute, the report said.
Five Atmospheric Brown Cloud (ABC) hotspots have been detected around the world, three of which are in Asia.
Asia's dense population and heady development of recent decades are two of the main reasons for the clouds, with one vast expanse of soot hovering across the Arabian Peninsula through to China and the western Pacific Ocean.
The clouds are so prevalent that black soot has been detected at Mount Everest base camp at levels normally expected in urban areas, according to the report.
The soot that has fallen on the glaciers of the Himalayas and other mountainous regions of Asia have amplified the effects of climate change, because the black particles absorb more heat.
However the clouds can both magnify and mask climate change, because the pollutants also block sunlight.
But the report said many of the consequences of the clouds were indisputable, such as accelerating the melting of glaciers, which in turn has a long-term negative impact on water resources and crop yields across Asia.
The pollutants have also contributed to decreases in the Indian summer monsoons and a north-south shift in rainfall patterns in China.
"The human fatalities from indoor and outdoor exposures to ABC-relevant pollutants have also become a source of grave concern," the report said.
The UNEP estimated that as many as 340,000 people died each year in China and India alone from cardiovascular, respiratory and other diseases linked to exposure to the pollutants.
UN: Clouds of pollution threaten glaciers, health
Tini Tran and John Heilprin, Associated Press Yahoo News 14 Nov 08;
BEIJING – A dirty brown haze sometimes more than a mile thick is darkening skies not only over vast areas of Asia, but also in the Middle East, southern Africa and the Amazon Basin, changing weather patterns around the world and threatening health and food supplies, the U.N. reported Thursday.
The huge smog-like plumes, caused mainly by the burning of fossil fuels and firewood, are known as "atmospheric brown clouds."
When mixed with emissions of carbon dioxide and other gases blamed for warming the earth's atmosphere like a greenhouse, they are the newest threat to the global environment, according to a report commissioned by the U.N. Environment Program.
"All of this points to an even greater and urgent need to look at emissions across the planet," said Achim Steiner, head of Kenya-based UNEP, which funded the report with backing from Italy, Sweden and the United States.
Brown clouds are caused by an unhealthy mix of particles, ozone and other chemicals that come from cars, coal-fired power plants, burning fields and wood-burning stoves. First identified by the report's lead researcher in 1990, the clouds were depicted Thursday as being more widespread and causing more environmental damage than previously known.
Perhaps most widely recognized as the haze this past summer over Beijing's Olympics, the clouds have been found to be more than a mile thick around glaciers in the Himalaya and Hindu Kush mountain ranges. They hide the sun and absorb radiation, leading to new worries not only about global climate change but also about extreme weather conditions.
"All these have led to negative effects on water resources and crop yields," the report says.
Health problems associated with particulate pollution, such as cardiovascular and respiratory diseases, are linked to nearly 350,000 premature deaths in China and India every year, said Henning Rohde, a University of Stockholm scientist who worked on the study.
Soot levels in the air were reported to have risen alarmingly in 13 megacities: Bangkok, Beijing, Cairo, Dhaka, Karachi, Kolkata, Lagos, Mumbai, New Delhi, Seoul, Shanghai, Shenzhen and Tehran.
Brown clouds were also cited as dimming the light by as much as 25 percent in some places including Karachi, New Delhi, Shanghai and Beijing.
The phenomenon complicates the climate change scenario, because the brown clouds also help cool the earth's surface and mask the impact of global warming by an average of 40 percent, according to the report.
Though it has been studied closely in Asia, the latest findings, conducted by an international collaboration of scientists, reveal that the brown cloud phenomenon is not unique to Asia, with pollution hotspots seen in North America, Europe, South Africa and South America.
More specifically, researchers found, brown clouds are forming over eastern China; northeastern Pakistan, India, Bangladesh and Myanmar; Cambodia, Indonesia, Thailand, and Vietnam; sub-Saharan Africa southward into Angola, Zambia and Zimbabwe; and the Amazon Basin in South America.
The enormous cloud masses can move across continents within three to four days. Although they also form over the eastern U.S. and Europe, winter snow and rain tend to lessen the impact in those areas.
An international response is needed to deal with "the twin threats of greenhouse gases and brown clouds and the unsustainable development that underpins both," said the lead researcher, Veerabhadran Ramanathan, a professor of climate and ocean sciences at the University of California in San Diego.
One of the most serious problems, Ramanathan said, is retreat of the glaciers in the Himalaya and Hindu Kush and in Tibet. The glaciers feed most Asian rivers and "have serious implications for the water and food security of Asia," he said.
Monsoon rains over India and southeast Asia decreased between 5 and 7 percent overall since the 1950s, the report says, naming brown clouds and global warming as a possible cause. Likewise, they may have contributed to the melting of China's glaciers, which have shrunk 5 percent since the 1950s. The volume of China's nearly 47,000 glaciers has fallen by 3,000 square kilometers (1,158.31 square miles) in the past 25 years, according to the Chinese Academy of Sciences.
Soot winds up on the surface of the glaciers that feed the Ganges, Indus, Yangtze and Yellow rivers, which makes the glaciers absorb more sunlight and melt more quickly and also pollutes the rivers, the researchers say.
But the U.N., which began studying the problem six years ago, still finds "significant uncertainty" in understanding how brown clouds affect conditions regionally, Ramanathan cautioned.
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Associated Press Writer John Heilprin contributed to this report from the United Nations.
Giant Asian smog cloud masks warming impact: U.N.
Emma Graham-Harrison, Reuters 13 Nov 08;
BEIJING (Reuters) - A three-kilometer thick cloud of brown soot and other pollutants hanging over Asia is darkening cities, killing thousands and damaging crops but may be holding off the worst effects of global warming, the U.N. said on Thursday.
The vast plume of contamination from factories, fires, cars and deforestation contains some particles that reflect sunlight away from the earth, cutting its ability to heat the earth.
"One of the impacts of this atmospheric brown cloud has been to mask the true nature of global warming on our planet," United Nations Environment Program head Achim Steiner said at the launch in Beijing of a new report on the phenomenon.
The amount of sunlight reaching earth through the murk has fallen by up to a quarter in the worst-affected areas and if the brown cloud disperses, global temperatures could rise by up to 2 degrees Celsius.
But the overall effect of slowing climate change is not the silver lining to a dark cloud that it appears to be.
The choking soup of pollutants may hold temperatures down overall, but the mix of particles means it is also speeding up warming in some of the most vulnerable areas and exacerbating the most devastating impacts of higher temperatures.
The complex impact of the cloud, which tends to cool areas near the surface of the earth and warm the air higher up, is believed to be causing a shortening of the monsoon season in India while increasing flooding there and in southern China.
Soot from the cloud is also deposited on glaciers, which are at the center of environmentalists' and politicians' concerns because they feed Asia's key rivers and provide drinking water for billions who live along them.
There the particles capture more solar heat than white, reflective snow and ice -- speeding up melting of a key resource. At a monitoring station near Mount Everest, soot has been found at levels which scientists say would be expected in urban areas.
There is also a high human cost. The report estimates round 340,000 people are dying prematurely because of damage to their lungs, hearts and risk of cancer.
DARKER CITIES, SMALLER HARVESTS?
Scientists are still studying the impact on crops, but possible problems include falling harvests because of less energy for photosynthesis and higher ozone concentrations.
There may also be damage from acidic and toxic particles in the cloud that land on plants, and wider changes to weather patterns may dry up or flood fields.
"The emergence of the atmospheric brown cloud problem is expected to further aggravate the recent dramatic escalation of food prices and the consequent challenge for survival among the world's most vulnerable populations," the report said.
One consolation, however, is that if the world stopped emitting the particles that form the cloud, it could be expected to vanish in weeks, unlike many longer-lasting greenhouse gasses.
The ingredients that make up the cloud are little different from the smog that cloaks many of the world's large cities, particularly in developing nations.
But scientists have realized this local pollution is a global problem, because of the way it rises and spreads.
"We used to think of the brown cloud as a regional-scale urban problem, now we know because of fast transport it travels vertically for three to four kilometers and spreads," said Professor Veerabhadran Ramanathan, head of the U.N. scientific panel which is carrying out the research.
There are similar brown clouds over parts of Europe, North America, Africa and the Amazon Basin, though research so far has been focused on the Asian cloud which stretches from the Arabian Peninsula to the Pacific Ocean.
(Editing by Valerie Lee)
Wide Spread and Complex Climatic Changes Outlined in New UNEP Project Atmospheric Brown Cloud Report
Cities Across Asia Get Dimmer: Impacts on Glaciers, Agriculture and the Monsoon Get Clearer
UNEP website 13 Nov 08;
Beijing/Nairobi, 13 November 2008 - Cities from Beijing to New Delhi are getting darker, glaciers in ranges like the Himalayas are melting faster and weather systems becoming more extreme, in part, due to the combined effects of man-made Atmospheric Brown Clouds (ABCs) and greenhouse gases in the atmosphere.
These are among the conclusions of scientists studying a more than three km-thick layer of soot and other manmade particles that stretches from the Arabian Peninsula to China and the western Pacific Ocean.
Today the team, drawn from research centres in Asia including China and India, Europe and the United States, announced their latest and most detailed assessment of the phenomenon.
The brown clouds, the result of burning of fossil fuels and biomass, are in some cases and regions aggravating the impacts of greenhouse gas-induced climate change, says the report.
This is because ABCs lead to the formation of particles like black carbon and soot that absorb sunlight and heat the air; and gases such as ozone which enhance the greenhouse effect of CO2.
Globally however brown clouds may be countering or 'masking' the warming impacts of climate change by between 20 and up to 80 per cent the researchers suggest.
This is because of particles such as sulfates and some organics which reflect sunlight and cool the surface.
The cloud is also having impacts on air quality and agriculture in Asia increasing risks to human health and food production for three billion people.
Achim Steiner, UN Under-Secretary General and Executive Director, UN Environment Programme (UNEP) said: "One of UNEP's central mandates is science-based early warning of serious and significant environmental challenges. I expect the Atmospheric Brown Cloud to be now firmly on the international community's radar as a result of today's report".
The phenomenon has been most intensively studied over Asia. This is in part because of the region's already highly variable climate including the formation of the annual Monsoon, the fact that the region is undergoing massive growth and is home to around half the world's population.
But the scientists today made clear that there are also brown clouds elsewhere including over parts of North America, Europe, southern Africa and the Amazon Basin which also require urgent and detailed research.
"Combating rising CO2 levels and climate change is the challenge of this generation but it is also the best bet the world has for Green Growth including new jobs and new enterprises from a booming solar and wind industry to more fuel efficient, vehicles, homes and workplaces. Developed countries must not only act first but also assist developing economies with the finance and clean technology needed to green energy generation and economic growth," said Mr Steiner.
"In doing so, they can not only lift the threat of climate change but also turn off the soot- stream that is feeding the formation of atmospheric brown clouds in many of the world's regions. This is because the source of greenhouse gases and soot are often one and the same - unsustainable burning of fossil fuels, inefficient combustion of biomass and deforestation," he added.
Professor Veerabhadran Ramanathan, head of the UNEP scientific panel which is carrying out the research said: "I would like to pay tribute to my distinguished colleagues, drawn from universities and research centres in Asia including China, India, Japan, Korea, Singapore and Thailand as well as Europe and the United States".
"Our preliminary assessment, published in 2002, triggered a great deal of awareness but also skepticism. That has often been the initial reaction to new, novel and far reaching, counter-intuitive scientific research," he said.
"We believe today's report brings ever more clarity to the ABC phenomena and in doing so must trigger an international response - one that tackles the twin threats of greenhouse gases and brown clouds and the unsustainable development that underpins both," added professor Ramanathan who is based at the Scripps Institution of Oceanography, La Jolla, California.
"One of the most serious problems highlighted in the report is the documented retreat of the Hind Kush-Himalayan-Tibetan glaciers, which provide the head-waters for most Asian rivers, and thus have serious implications for the water and food security of Asia," he said.
"The new research, by identifying some of the causal factors, offers hope for taking actions to slow down this disturbing phenomenon; it should be cautioned that significant uncertainty remains in our understanding of the complexity of the regional effects of ABCs and more surprises may await us " added Professor Ramanathan.
Highlights from Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia
Five regional hotspots for ABCs have been indentified. These are:
* East Asia, covering eastern China;
* The Indo-Gangetic plains in South Asia from the northwest and northeast regions of eastern Pakistan across India to Bangladesh and Myanmar;
* Southeast Asia, covering Cambodia, Indonesia, Thailand, and Vietnam;
* Southern Africa extending southwards from sub-Saharan Africa into Angola, Zambia and Zimbabwe; and
* The Amazon Basin in South America.
There are hotspots too in North America over the eastern seaboard and in Europe - but winter precipitation tends to remove them and reduce their impact.
Cities and 'Dimming'
Around 13 megacities have so far been identified as ABC hotpots.
Bangkok, Beijing, Cairo, Dhaka, Karachi, Kolkata, Lagos, Mumbai, New Delhi, Seoul, Shanghai, Shenzhen and Tehran where soot levels are 10 per cent of the total mass of all human-made particles.
ABCs can reduce sunlight hitting the Earth's surface in two ways.
Some of the particles such as sulphates, linked with burning coal and other fossil fuels, reflect and scatter rays back into space.
Others, also linked with fossil fuel and biomass burning, in particular black carbon in soot, absorb sunlight before it reaches the ground. The overall effect is to make 'hot spot' cities darker or dimmer.
* 'Dimming' of between 10-25 per cent is occurring over cities such as Karachi, Beijing, Shanghai and New Delhi
* Guangzhou is among several cities that have recorded a more than 20 per cent reduction in sunlight since the 1970s
* For India as a whole, the dimming trend has been running at about two per cent per decade between 1960 and 2000 - more than doubling between 1980 and 2004.
* "In China the observed dimming trend from the 1950s to the 1990s was about 3-4 per cent per decade, with the larger trends after the 1970s," says the report.
Impact on Cloud Formation and a Further Dimming Effect
* Regions with large concentrations of ABCs may be getting cloudier which can also contribute to dimming but data are not sufficient to quantify this effect.
* Particles and aerosols in the ABCs may act to inhibit the formation of rain drops and rainfall. "The net effect is an extension of cloud life-times," says the report.
Masking the Impacts of Climate Change
ABCs shield the surface from sunlight by reflecting solar radiation back to space and by absorbing heat in the atmosphere.
These two dimming phenomena can act to artificially cool the Earth's surface especially during dry seasons. The pollution can also be transported around the world via winds in the upper troposphere (above 5 km in altitude).
* As a result global temperature rises - linked with greenhouse gas emissions - may currently be between 20 per cent and 80 per cent less as a result of brown clouds around the world says the report.
* If brown clouds were eliminated overnight, this could trigger a rapid global temperature rise of as much as to 2 degrees C.
* Added to the 0.75 degrees C rise of the 20th century, this could push global temperatures well above 2 degrees C - considered by many scientists to be a crucial and dangerous threshold.
* Thus simply tackling the pollution linked with brown cloud formation without simultaneously delivering big cuts in greenhouse gases could have a potentially disastrous effect.
Complex Regional Impacts on Temperature
The science of ABCs, woven with the science of greenhouse gases, is not simple and may be behind some highly complex warming and cooling patterns witnessed on Continents and in different regions of specific countries.
* The masking of greenhouse warming by ABCs may in part be the explanation for the lack of a strong warming trend over India since the 1950s during the dry season which runs from January to May.
* ABCs may explain in part why the warming trend in India's night time temperatures is much larger than the trend in day time temperatures.
* Annual mean temperatures in mainland China have risen by over one degree C in the past half century.
* However the trends have not been uniform with the Tibetan Plateau and the North, Northeast and Northwest of China experiencing the highest temperature rises.
* Conversely Southwest and central Eastern China has experienced a strong cooling trend of between 0.1 to 0.3 degrees C per decade.
* "The combined effects of greenhouse gases, ABCs and rapid urbanization are required to explain the complex pattern of warming and cooling trends in China," says the report.
Impacts on Weather Patterns Including the East Asian Monsoon
The large heating and cooling effects of ABCs respectively in the atmosphere and at the surface, combined with the impacts of greenhouse gases, may be also triggering sharp shifts in weather patterns.
This is being aggravated by dimming over the Northern Indian Ocean versus the relatively clean Southern Indian Ocean setting up new gradients in surface sea temperatures and surface sea evaporation rates.
ABCs, along with the global warming may thus be acting to trigger significant drying in northern China and increased risk of flooding in southern China while in part also triggering other environmental and economic effects.
* Overall decrease in monsoon precipitation over India and Southeast Asia by between five and seven per cent since the 1950s.
* Since the 1950s the Indian summer monsoon is not only weakening but shrinking with a decrease in early and late season rainfall and a decline in the number of rainy days.
* In both China and India extreme rain events of more than 100 mm a day have increased.
* In both India and China very heavy rainfall of more than 150 mm a day have nearly doubled.
Impact on Glaciers
The Hindu Kush-Himalaya-Tibetan glaciers provide the head-waters for the major river systems including the Ganges, Brahmaputra, Mekong and Yangtze rivers.
The Ganges basin is home to over 400 million people and holds 40 per cent of India's irrigated croplands.
The Chinese Academy of Sciences estimates that the glaciers have shrunk five per cent since the 1950s and the volume of China's nearly 47,000 glaciers has fallen by 3,000 square km over the past quarter century.
Glaciers in India such as the Siachen, Gangotri and Chhota Shigiri glaciers are retreating at rates of between 10 and 25 metres a year. The retreat has accelerated in the past three and-a-half decades.
The Gangotri glacier alone provides up to 70 per cent of the water in the Ganges.
* ABC solar heating of the atmosphere, due to the absorption of soot and black carbon pollution "is suggested to be as important as greenhouse gas warming in accounting for the anomalously large warming trend observed in the elevated regions" such as the Himalayan-Tibetan region says the report.
* Decreased reflection of solar radiation by snow and ice due to increasing deposits of black carbon is emerging as another major contributor to the melting of ice and snow.
* Elevated regions of the Himalayas within 100 km of Mount Everest experience large black carbon concentrations ranging from a few hundred to a few thousand nano grammes per cubic metre.
Impacts on Agriculture
Impacts of ABCs on food production and farmers' livelihoods may be many.
However there remains a great deal more research to undertake in terms of crops at risk and the precise role various ABC-linked effects - separately or in combination with those of greenhouse gases - may or may not be having.
Possible effects may include
* Damage to crops as a result of increased ground level ozone. In Europe a threshold concentration at which damage can occur is deemed to be 40 parts per billion
* The report says that in parts of Asia ground level ozone can reach 50 parts per billion during February to June and peaking again between September and November at 40 parts per billion
* The studies suggest that growing season mean ozone concentrations in the range 30 - 45 parts per billion could see crop yield losses in the region of 10 - 40 per cent for sensitive cultivars of important Asian crops such as wheat rice and legumes
* A recent study translated such impacts on yield into annual economic losses estimating that for four key crops - wheat, rice, corn and soya bean - these may amount to around $5 billion a year across China, the Republic of Korea and Japan
* Other effects may include damage linked with the various acidic and toxic particles from brown clouds depositing on plants from the atmosphere
* Reduced levels of photosynthesis and thus crop production due to 'dimming'
Health Impacts of ABCs
Brown clouds contain a variety of toxic aerosols, carcinogens and particles including particulate matter (PM) of less than 2.5 microns in width. These have been linked with a variety of health effects from respiratory disease and cardio-vascular problems.
* Outdoor exposure - Increases in concentrations of PM 2.5 of 20 microgrammes per cubic metre could lead to about 340,000 excess deaths per year in China and India
* Indoor exposure - the World Health Organization estimates that over 780,000 deaths in the two countries can be linked to solid fuel use in the home
* Economic losses due to outdoor exposure to ABC-related PM2.5 has been crudely estimated at 3.6 per cent of GDP in China and 2.2 per cent of GDP in India
Notes to Editors
Project Atmospheric Brown Cloud was established by the United Nations Environment Programme (UNEP) in 2002 following the documentation of brown clouds and haze by the Indian Ocean Experiment (INDOEX).
The science secretariat of ABC is located at the Center for Clouds, Chemistry and Climate, Scripps Institution of Oceanography, UCSD.
The current project is funded by UNEP with support from the governments of Italy, Sweden and the United States.
Atmospheric Brown Clouds: Regional Assessment Report with Focus on Asia can be found at www.unep.org
