Tag Archives: Black carbon

Soot 'melted Alps glaciers, not heat'

FOR IMMEDIATE RELEASE
The Alps of central Europe began melting many years before there was any influence from climate change. Scientists now say it was not rising temperatures that triggered the melt, but pollution.

LONDON, 4 September – Scientists think they know why some European glaciers started to shrink decades before climate change had begun to raise temperatures.

It wasn’t warming that attacked the glaciers, they say in the Proceedings of the National Academy of Sciences. It was soot from industry, steam locomotives and domestic fires.

Glaciologists have for years been puzzled by the sudden start in the middle of the 19th century of the retreat of the Alpine glaciers, which number around 4,000.

They had survived in good condition from the 13th century throughout the fairly cool 500-year period called the Little Ice Age. They reached their greatest extent in the mid-1800s, about double what they are now.

But even though it remained cool the glaciers suddenly began shrinking, leading scientists to believe that the Little Ice Age had ended around 1850.

Average global temperatures, though, did not rise significantly – until the end of the 19th century. In fact, Alpine climate records – among the most extensive and reliable in the world  – suggest that the glaciers should have continued to grow for another 50 years or more, until about 1910.

Risk of dirty washing

The scientists acknowledge that other parts of the world may also have been affected, but point out that the decline was well documented only in the Alps.

However, soot is also a big concern in the Himalayas, at high altitudes in some regions bigger than temperature rises. The burgeoning economies of China and India contribute huge amounts.

“Something gnawed on the glaciers that climate records don’t capture,” said Georg Kaser, a glaciologist at the University of Innsbruck in Austria and a member of the team that identified black carbon, or soot, as the cause.

“A strong decline in winter snowfall was often assumed to be the culprit. But from all that we know, no such decline occurred.”

Because darker surfaces absorb more heat than lighter, more reflective ones, if enough soot is deposited on snow and ice it can accelerate melting.

Records suggest that by the mid-19th century the air in some Alpine valleys was laden with pollution. “Housewives in Innsbruck refrained from drying laundry outdoors,” says Kaser.

Gone by 2100?

Scientists used to think soot was unlikely to have been carried high enough to start the glaciers melting, but they now appear to have been mistaken.

When Kaser’s team looked at ice cores previously drilled at two sites high in the western Alps – the Colle Gnifetti glacier saddle 4,455 m up on Monte Rosa near the Swiss–Italian border, and the Fiescherhorn glacier at 3,900 m in the Bernese Alps – they found that in around 1860 layers of glacial ice started to contain large amounts of soot.

The team measured the effect the soot would have had on glaciers at the time in terms of  equivalent changes in air temperature. They found that the melting effect of black carbon provided a good explanation of the observed glacier retreat.

Andreas Vieli, a glaciologist at the University of Zurich in Switzerland (who was not involved in the study) said: “…[T]his study offers a very elegant and plausible explanation for the glacier conundrum. It appears that in central Europe soot prematurely stopped the Little Ice Age.”

Only after around 1970, when air quality began to improve, did accelerated climate warming become the dominant driver of Alpine glacier retreat, Kaser says.

He says that if glaciers in the region continue to melt at the rate seen during the past 30 years, there is a risk that nearly all of them will vanish before the end of the century. – Climate News Network

FOR IMMEDIATE RELEASE
The Alps of central Europe began melting many years before there was any influence from climate change. Scientists now say it was not rising temperatures that triggered the melt, but pollution.

LONDON, 4 September – Scientists think they know why some European glaciers started to shrink decades before climate change had begun to raise temperatures.

It wasn’t warming that attacked the glaciers, they say in the Proceedings of the National Academy of Sciences. It was soot from industry, steam locomotives and domestic fires.

Glaciologists have for years been puzzled by the sudden start in the middle of the 19th century of the retreat of the Alpine glaciers, which number around 4,000.

They had survived in good condition from the 13th century throughout the fairly cool 500-year period called the Little Ice Age. They reached their greatest extent in the mid-1800s, about double what they are now.

But even though it remained cool the glaciers suddenly began shrinking, leading scientists to believe that the Little Ice Age had ended around 1850.

Average global temperatures, though, did not rise significantly – until the end of the 19th century. In fact, Alpine climate records – among the most extensive and reliable in the world  – suggest that the glaciers should have continued to grow for another 50 years or more, until about 1910.

Risk of dirty washing

The scientists acknowledge that other parts of the world may also have been affected, but point out that the decline was well documented only in the Alps.

However, soot is also a big concern in the Himalayas, at high altitudes in some regions bigger than temperature rises. The burgeoning economies of China and India contribute huge amounts.

“Something gnawed on the glaciers that climate records don’t capture,” said Georg Kaser, a glaciologist at the University of Innsbruck in Austria and a member of the team that identified black carbon, or soot, as the cause.

“A strong decline in winter snowfall was often assumed to be the culprit. But from all that we know, no such decline occurred.”

Because darker surfaces absorb more heat than lighter, more reflective ones, if enough soot is deposited on snow and ice it can accelerate melting.

Records suggest that by the mid-19th century the air in some Alpine valleys was laden with pollution. “Housewives in Innsbruck refrained from drying laundry outdoors,” says Kaser.

Gone by 2100?

Scientists used to think soot was unlikely to have been carried high enough to start the glaciers melting, but they now appear to have been mistaken.

When Kaser’s team looked at ice cores previously drilled at two sites high in the western Alps – the Colle Gnifetti glacier saddle 4,455 m up on Monte Rosa near the Swiss–Italian border, and the Fiescherhorn glacier at 3,900 m in the Bernese Alps – they found that in around 1860 layers of glacial ice started to contain large amounts of soot.

The team measured the effect the soot would have had on glaciers at the time in terms of  equivalent changes in air temperature. They found that the melting effect of black carbon provided a good explanation of the observed glacier retreat.

Andreas Vieli, a glaciologist at the University of Zurich in Switzerland (who was not involved in the study) said: “…[T]his study offers a very elegant and plausible explanation for the glacier conundrum. It appears that in central Europe soot prematurely stopped the Little Ice Age.”

Only after around 1970, when air quality began to improve, did accelerated climate warming become the dominant driver of Alpine glacier retreat, Kaser says.

He says that if glaciers in the region continue to melt at the rate seen during the past 30 years, there is a risk that nearly all of them will vanish before the end of the century. – Climate News Network

Soot ‘melted Alps glaciers, not heat’

FOR IMMEDIATE RELEASE The Alps of central Europe began melting many years before there was any influence from climate change. Scientists now say it was not rising temperatures that triggered the melt, but pollution. LONDON, 4 September – Scientists think they know why some European glaciers started to shrink decades before climate change had begun to raise temperatures. It wasn’t warming that attacked the glaciers, they say in the Proceedings of the National Academy of Sciences. It was soot from industry, steam locomotives and domestic fires. Glaciologists have for years been puzzled by the sudden start in the middle of the 19th century of the retreat of the Alpine glaciers, which number around 4,000. They had survived in good condition from the 13th century throughout the fairly cool 500-year period called the Little Ice Age. They reached their greatest extent in the mid-1800s, about double what they are now. But even though it remained cool the glaciers suddenly began shrinking, leading scientists to believe that the Little Ice Age had ended around 1850. Average global temperatures, though, did not rise significantly – until the end of the 19th century. In fact, Alpine climate records – among the most extensive and reliable in the world  – suggest that the glaciers should have continued to grow for another 50 years or more, until about 1910.

Risk of dirty washing

The scientists acknowledge that other parts of the world may also have been affected, but point out that the decline was well documented only in the Alps. However, soot is also a big concern in the Himalayas, at high altitudes in some regions bigger than temperature rises. The burgeoning economies of China and India contribute huge amounts. “Something gnawed on the glaciers that climate records don’t capture,” said Georg Kaser, a glaciologist at the University of Innsbruck in Austria and a member of the team that identified black carbon, or soot, as the cause. “A strong decline in winter snowfall was often assumed to be the culprit. But from all that we know, no such decline occurred.” Because darker surfaces absorb more heat than lighter, more reflective ones, if enough soot is deposited on snow and ice it can accelerate melting. Records suggest that by the mid-19th century the air in some Alpine valleys was laden with pollution. “Housewives in Innsbruck refrained from drying laundry outdoors,” says Kaser.

Gone by 2100?

Scientists used to think soot was unlikely to have been carried high enough to start the glaciers melting, but they now appear to have been mistaken. When Kaser’s team looked at ice cores previously drilled at two sites high in the western Alps – the Colle Gnifetti glacier saddle 4,455 m up on Monte Rosa near the Swiss–Italian border, and the Fiescherhorn glacier at 3,900 m in the Bernese Alps – they found that in around 1860 layers of glacial ice started to contain large amounts of soot. The team measured the effect the soot would have had on glaciers at the time in terms of  equivalent changes in air temperature. They found that the melting effect of black carbon provided a good explanation of the observed glacier retreat. Andreas Vieli, a glaciologist at the University of Zurich in Switzerland (who was not involved in the study) said: “…[T]his study offers a very elegant and plausible explanation for the glacier conundrum. It appears that in central Europe soot prematurely stopped the Little Ice Age.” Only after around 1970, when air quality began to improve, did accelerated climate warming become the dominant driver of Alpine glacier retreat, Kaser says. He says that if glaciers in the region continue to melt at the rate seen during the past 30 years, there is a risk that nearly all of them will vanish before the end of the century. – Climate News Network

FOR IMMEDIATE RELEASE The Alps of central Europe began melting many years before there was any influence from climate change. Scientists now say it was not rising temperatures that triggered the melt, but pollution. LONDON, 4 September – Scientists think they know why some European glaciers started to shrink decades before climate change had begun to raise temperatures. It wasn’t warming that attacked the glaciers, they say in the Proceedings of the National Academy of Sciences. It was soot from industry, steam locomotives and domestic fires. Glaciologists have for years been puzzled by the sudden start in the middle of the 19th century of the retreat of the Alpine glaciers, which number around 4,000. They had survived in good condition from the 13th century throughout the fairly cool 500-year period called the Little Ice Age. They reached their greatest extent in the mid-1800s, about double what they are now. But even though it remained cool the glaciers suddenly began shrinking, leading scientists to believe that the Little Ice Age had ended around 1850. Average global temperatures, though, did not rise significantly – until the end of the 19th century. In fact, Alpine climate records – among the most extensive and reliable in the world  – suggest that the glaciers should have continued to grow for another 50 years or more, until about 1910.

Risk of dirty washing

The scientists acknowledge that other parts of the world may also have been affected, but point out that the decline was well documented only in the Alps. However, soot is also a big concern in the Himalayas, at high altitudes in some regions bigger than temperature rises. The burgeoning economies of China and India contribute huge amounts. “Something gnawed on the glaciers that climate records don’t capture,” said Georg Kaser, a glaciologist at the University of Innsbruck in Austria and a member of the team that identified black carbon, or soot, as the cause. “A strong decline in winter snowfall was often assumed to be the culprit. But from all that we know, no such decline occurred.” Because darker surfaces absorb more heat than lighter, more reflective ones, if enough soot is deposited on snow and ice it can accelerate melting. Records suggest that by the mid-19th century the air in some Alpine valleys was laden with pollution. “Housewives in Innsbruck refrained from drying laundry outdoors,” says Kaser.

Gone by 2100?

Scientists used to think soot was unlikely to have been carried high enough to start the glaciers melting, but they now appear to have been mistaken. When Kaser’s team looked at ice cores previously drilled at two sites high in the western Alps – the Colle Gnifetti glacier saddle 4,455 m up on Monte Rosa near the Swiss–Italian border, and the Fiescherhorn glacier at 3,900 m in the Bernese Alps – they found that in around 1860 layers of glacial ice started to contain large amounts of soot. The team measured the effect the soot would have had on glaciers at the time in terms of  equivalent changes in air temperature. They found that the melting effect of black carbon provided a good explanation of the observed glacier retreat. Andreas Vieli, a glaciologist at the University of Zurich in Switzerland (who was not involved in the study) said: “…[T]his study offers a very elegant and plausible explanation for the glacier conundrum. It appears that in central Europe soot prematurely stopped the Little Ice Age.” Only after around 1970, when air quality began to improve, did accelerated climate warming become the dominant driver of Alpine glacier retreat, Kaser says. He says that if glaciers in the region continue to melt at the rate seen during the past 30 years, there is a risk that nearly all of them will vanish before the end of the century. – Climate News Network

Frack first, repent at leisure

FOR IMMEDIATE RELEASE The arguments for and against fracking seem clear-cut. But it’s not that simple, and there is mounting evidence that exploiting shale gas may be neither necessary nor sensible. LONDON, 17 August – As the international debate intensifies over the arguments for and against exploiting shale gas, the largest British nature conservation charity has objected to proposals to drill at two sites in Britain. The Royal Society for the Protection of Birds is concerned that fracking – hydraulic fracturing of underground rock – at a site in northern England close to an internationally important protected area for pink-footed geese and whooper swans could disturb the birds. With the second site, in the south of England, the RSPB is objecting because it says the developers have not carried out an assessment of the environmental impact of the exploitation. But significantly, the conservationists are raising a second objection as well: that “increasing oil and gas use will scupper our chances of meeting climate targets.” Some supporters of shale exploitation say the cheaper and (relatively) cleaner energy it would produce could serve as a bridge to usher the UK into an era of secure supplies and low-carbon emissions. Others see shale not as a bridge but as a dead end. The RSPB concludes: “…concentrating our resources on extracting fossil fuel from the ground instead of investing in renewable energy threatens to undermine our commitment to avoiding dangerous levels of climate change.”

Coal’s silver lining

But one climate scientist uses a different argument against shale gas: he says exploiting it could in fact worsen climate change, the very problem it is meant to solve. Tom Wigley, of the National Center for Atmospheric Research in Boulder, Colorado, reported as long ago as 2011 in the journal Climatic Change that replacing coal with gas could increase the rate of global warming for decades to come. Dr Wigley concluded that carbon dioxide emissions from fossil fuel combustion could certainly be cut by burning natural gas rather than coal, as gas produces about half as much CO2 for each unit of primary energy as coal does. But coal does something else as well. It releases a lot of sulphur dioxide and black carbon, which help to cool the climate. The British journalist Fred Pearce, writing in the journal New Scientist, says Wigley told a recent conference that these releases counteract up to 40% of the warming effect of burning coal. Additionally, the technology used in fracking also causes methane to leak into the atmosphere. Methane is at least 23% more potent as a greenhouse gas than CO2, and Dr Wigley says a change from coal to gas will bring benefits this century only if leakage rates are below 2%.

Easier low-tech solution

If they reached 10%, the highest current US estimate, the gas would increase rather than decrease global warming until the middle of the next century, though the overall effects on global average temperature over that century would be small. And even if resorting to shale gas does not worsen climate change, it can still be an unnecessarily hi-tech solution which blinds its supporters to a far simpler answer, some critics argue. The London Guardian quotes the UK’s Anaerobic Digestion and Biogas Association as saying a tenth of the country’s domestic gas needs could be supplied by biogas, given the UK’s wealth of waste and agricultural products. This, the Association says, could save the UK at least 7.5m tonnes of CO2 a year, because the waste would otherwise be sent to landfill or left to rot and release methane. The country is estimated to produce 15 million tonnes of food waste a year, and about 90 m tonnes of another potent source of energy, animal waste. But only a small part of both is used for producing energy. One British company which is successfully exploiting the bio-waste market is producing electricity and fertiliser, and also preventing the release of thousands of tonnes of CO2 annually. – Climate News Network

FOR IMMEDIATE RELEASE The arguments for and against fracking seem clear-cut. But it’s not that simple, and there is mounting evidence that exploiting shale gas may be neither necessary nor sensible. LONDON, 17 August – As the international debate intensifies over the arguments for and against exploiting shale gas, the largest British nature conservation charity has objected to proposals to drill at two sites in Britain. The Royal Society for the Protection of Birds is concerned that fracking – hydraulic fracturing of underground rock – at a site in northern England close to an internationally important protected area for pink-footed geese and whooper swans could disturb the birds. With the second site, in the south of England, the RSPB is objecting because it says the developers have not carried out an assessment of the environmental impact of the exploitation. But significantly, the conservationists are raising a second objection as well: that “increasing oil and gas use will scupper our chances of meeting climate targets.” Some supporters of shale exploitation say the cheaper and (relatively) cleaner energy it would produce could serve as a bridge to usher the UK into an era of secure supplies and low-carbon emissions. Others see shale not as a bridge but as a dead end. The RSPB concludes: “…concentrating our resources on extracting fossil fuel from the ground instead of investing in renewable energy threatens to undermine our commitment to avoiding dangerous levels of climate change.”

Coal’s silver lining

But one climate scientist uses a different argument against shale gas: he says exploiting it could in fact worsen climate change, the very problem it is meant to solve. Tom Wigley, of the National Center for Atmospheric Research in Boulder, Colorado, reported as long ago as 2011 in the journal Climatic Change that replacing coal with gas could increase the rate of global warming for decades to come. Dr Wigley concluded that carbon dioxide emissions from fossil fuel combustion could certainly be cut by burning natural gas rather than coal, as gas produces about half as much CO2 for each unit of primary energy as coal does. But coal does something else as well. It releases a lot of sulphur dioxide and black carbon, which help to cool the climate. The British journalist Fred Pearce, writing in the journal New Scientist, says Wigley told a recent conference that these releases counteract up to 40% of the warming effect of burning coal. Additionally, the technology used in fracking also causes methane to leak into the atmosphere. Methane is at least 23% more potent as a greenhouse gas than CO2, and Dr Wigley says a change from coal to gas will bring benefits this century only if leakage rates are below 2%.

Easier low-tech solution

If they reached 10%, the highest current US estimate, the gas would increase rather than decrease global warming until the middle of the next century, though the overall effects on global average temperature over that century would be small. And even if resorting to shale gas does not worsen climate change, it can still be an unnecessarily hi-tech solution which blinds its supporters to a far simpler answer, some critics argue. The London Guardian quotes the UK’s Anaerobic Digestion and Biogas Association as saying a tenth of the country’s domestic gas needs could be supplied by biogas, given the UK’s wealth of waste and agricultural products. This, the Association says, could save the UK at least 7.5m tonnes of CO2 a year, because the waste would otherwise be sent to landfill or left to rot and release methane. The country is estimated to produce 15 million tonnes of food waste a year, and about 90 m tonnes of another potent source of energy, animal waste. But only a small part of both is used for producing energy. One British company which is successfully exploiting the bio-waste market is producing electricity and fertiliser, and also preventing the release of thousands of tonnes of CO2 annually. – Climate News Network

Black carbon flows from soil to seas

FOR IMMEDIATE RELEASE Charcoal and other forms of black carbon do not, as previously thought, stay where they are buried: they migrate to the oceans and recirculate the carbon they contain. LONDON, 25 April – Climate scientists may have to rethink some of their old assumptions about carbon. US and European researchers have just established that black carbon, soot and biochar – the burnt remains from countless forest fires –  doesn’t stay in the soil indefinitely. Around 27 million tons of the stuff gets dissolved in water and washed down the rivers into the oceans each year. Black carbon or biochar has been hailed as one possible way of limiting greenhouse gas emissions, by taking carbon out of circulation. But this study, according to a report in the journal Science, “closes a major gap in the global charcoal budget and provides critical information in the context of geo-engineering”. Forest, bush, scrub and peat fires produce somewhere between 40 and 250 million tons of black carbon every year. Had this burning been complete, this would have ended up as carbon dioxide, back in the atmosphere. So researchers have counted the biochar locked in the soil – where it enhances fertility – as carbon out of circulation for millions of years. But analysis of water from the world’s 10 largest rivers – the Amazon, the Yangtse, the Congo and so on – told a different story. “Each sample included a significant amount of black carbon”, said Anssi Vähätalo, now of the University of Jyväskylä in Finland. “On average, the amount of black carbon was 10% of the amount of dissolved organic carbon. “The results prove that the proportion of water-soluble carbon may be as much as 40% of black carbon created annually.” The sampled rivers carry one third of the water running to the oceans, from a catchment area that embraces 28% of the planet’s land area.

More CO2 released

  The research is yet another step in the long and tricky international effort to understand just how the world works: how life’s raw materials are consumed, exploited and recycled, and why greenhouse gas emissions are stubbornly on the increase. Fossil fuel burning puts back into the atmosphere the carbon dioxide – and the warmth – locked away in the Carboniferous period and buried for 300 million years. Log fires simply restore carbon dioxide to the atmosphere that was locked up a few decades earlier, in the growing tree: log fires in that sense are carbon neutral, or even carbon negative, since a lot of the carbon lingers and is buried as ash, soot or charcoal. Some environmentalists have argued that greater use of biochar could slow and perhaps ultimately reduce global warming by taking carbon out of circulation. The accounting may not be so simple. “Most scientists thought charcoal was resistant. They thought, once it is incorporated in the soils, it would stay there,” said Rudolf Jaffé from Florida University. “When charcoal forms it is typically deposited in the soil. From a chemical perspective, no one really thought it dissolves, but it does. “It doesn’t accumulate, like we had for a long time believed. Rather, it is transported into wetlands and rivers, eventually making its way into the oceans.” – Climate News Network

FOR IMMEDIATE RELEASE Charcoal and other forms of black carbon do not, as previously thought, stay where they are buried: they migrate to the oceans and recirculate the carbon they contain. LONDON, 25 April – Climate scientists may have to rethink some of their old assumptions about carbon. US and European researchers have just established that black carbon, soot and biochar – the burnt remains from countless forest fires –  doesn’t stay in the soil indefinitely. Around 27 million tons of the stuff gets dissolved in water and washed down the rivers into the oceans each year. Black carbon or biochar has been hailed as one possible way of limiting greenhouse gas emissions, by taking carbon out of circulation. But this study, according to a report in the journal Science, “closes a major gap in the global charcoal budget and provides critical information in the context of geo-engineering”. Forest, bush, scrub and peat fires produce somewhere between 40 and 250 million tons of black carbon every year. Had this burning been complete, this would have ended up as carbon dioxide, back in the atmosphere. So researchers have counted the biochar locked in the soil – where it enhances fertility – as carbon out of circulation for millions of years. But analysis of water from the world’s 10 largest rivers – the Amazon, the Yangtse, the Congo and so on – told a different story. “Each sample included a significant amount of black carbon”, said Anssi Vähätalo, now of the University of Jyväskylä in Finland. “On average, the amount of black carbon was 10% of the amount of dissolved organic carbon. “The results prove that the proportion of water-soluble carbon may be as much as 40% of black carbon created annually.” The sampled rivers carry one third of the water running to the oceans, from a catchment area that embraces 28% of the planet’s land area.

More CO2 released

  The research is yet another step in the long and tricky international effort to understand just how the world works: how life’s raw materials are consumed, exploited and recycled, and why greenhouse gas emissions are stubbornly on the increase. Fossil fuel burning puts back into the atmosphere the carbon dioxide – and the warmth – locked away in the Carboniferous period and buried for 300 million years. Log fires simply restore carbon dioxide to the atmosphere that was locked up a few decades earlier, in the growing tree: log fires in that sense are carbon neutral, or even carbon negative, since a lot of the carbon lingers and is buried as ash, soot or charcoal. Some environmentalists have argued that greater use of biochar could slow and perhaps ultimately reduce global warming by taking carbon out of circulation. The accounting may not be so simple. “Most scientists thought charcoal was resistant. They thought, once it is incorporated in the soils, it would stay there,” said Rudolf Jaffé from Florida University. “When charcoal forms it is typically deposited in the soil. From a chemical perspective, no one really thought it dissolves, but it does. “It doesn’t accumulate, like we had for a long time believed. Rather, it is transported into wetlands and rivers, eventually making its way into the oceans.” – Climate News Network

Nepal's glaciers retreat – but why?

EMBARGOED until 0001 GMT Saturday 23 February
One of the Climate News Network’s editors, Kieran Cooke, was among a group of journalists recently investigating the impact of climate change in Nepal and the Himalayas. In the last of his reports from the region he describes the difficulties of establishing why so many of Nepal’s glaciers appear to be shrinking.

KATHMANDU, 21 February – Mohan Bdr. Chand is at the sharp end of glacier research. A climate researcher at Kathmandu University, Chand is carrying out vital field work, looking at high mountain glaciers as indicators of climate change.

The work involves spending time clambering up and down the ice, taking measurements and readings to calculate mass balance – the sum of the snowfall which builds up on a glacier and the melting that shrinks it.

“Getting to a glacier can take five days from Kathmandu – two days driving and three days trekking”, says Chand, one of only a few native glacier specialists in Nepal. “We stay on the glacier for over two weeks at heights of between 5,000 and 6,000 metres. Conditions are tough, with altitude sickness a big problem.

“What we’re seeing is that almost all glaciers in Nepal are in retreat”, says Chand. “There are a few in the far west of the country which appear to be stable or increasing in size, but these – influenced by westerly winds rather than the Indian monsoon – are very much the exception.”

Calculating mass balance is seen as critical to understanding a glacier’s long-term behaviour. According to a 2011 study by the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD), there are an estimated 54,000 individual glaciers in the Hindu Kush-Himalayan region, an area of mountains stretching from Afghanistan in the west to Yunnan in southwest China in the east.

“The glaciers in much of the region show signs of shrinking, thinning and retreating”, said the study.

What is noteworthy is how little detailed knowledge there is of this region, which is considered to be highly vulnerable to climate change and to be warming faster than many other areas on the planet.

Retreat rates vary

 

“A serious lack of reliable and consistent data severely hampers scientific knowledge about the state of Himalayan glaciers”, said a late 2012 report by the United Nations Environment Programme’s global environmental alert service.

The region has been referred to as a “white spot”, a term in the 2007 IPCC (Intergovernmental Panel on Climate Change’s) Fourth Assessment Report used to describe an area with “little or no data”.

Confusion was added to the debate when, in the same IPCC report, it was suggested that the probability of  the Himalayan glaciers disappearing by 2035 “is very high if the Earth keeps warming at the present rate.”

It was a claim the IPCC later said should never have been published, but one that was eagerly seized on by climate sceptics in efforts to try to undermine the whole body of the Panel’s work.

Mohan and his team are investigating two glaciers – one at Rikhashambha in north-central Nepal at 6,000 metres, described as a valley glacier, and one at Yala to the east, on the border with Tibet at between 5,100 and 5,700 metres, described as a plateau-type glacier.

“In general plateau-type glaciers – mostly found in Tibet – seem to be retreating faster than valley types”, says Dr Mohan. “The number of glacial lakes at high altitudes is increasing, with between 20 and 26 in Nepal. If these burst, they pose a serious danger.

“Rising temperatures and sudden rainfalls of great intensity are factors that seem to be causing the retreat of some glaciers. But recently it’s been realised that black carbon could have a major impact on the mass balance of glaciers.”

Black carbon – particulate matter that in South Asia comes mainly from the burning of wood and waste and from cooking fires, or from coal-burning and diesel exhausts – falls on snow and darkens the surface, in the process reducing reflectivity and causing the surface to absorb more heat.

Data too sparse

 

Most of the black carbon falling on the Himalayas and the south of the Tibetan plateau comes from the plains of India, while that of the eastern and northern sections of the plateau comes mainly from China.

According to recent ICIMOD estimates, black carbon is probably responsible for a large part – around 30% by some calculations – of glacial retreat in the region.

ICIMOD and other bodies admit there is far too little field data available to draw solid conclusions, whether on overall glacial melt or on the influence of black carbon. Part of this is to do with the inhospitable terrain. Also, in a tense region where transboundary cooperation is severely limited, studies that have been done often use differing methodologies.

Advances in satellite technology have significantly increased the volume and quality of data gathering across the region. However, satellite survey results have shown considerable variation, with one survey finding large glacial retreat and another a much smaller rate of melt. Scientists say there is often no substitute for fieldwork but admit that the extent of such activity is still woefully inadequate.

“We will return to the glaciers in May to take more measurements”, says Chand. It is gruelling work but needs to be done if a full picture of what’s going in the glaciers of the Himalayas is to emerge. – Climate News Network

EMBARGOED until 0001 GMT Saturday 23 February
One of the Climate News Network’s editors, Kieran Cooke, was among a group of journalists recently investigating the impact of climate change in Nepal and the Himalayas. In the last of his reports from the region he describes the difficulties of establishing why so many of Nepal’s glaciers appear to be shrinking.

KATHMANDU, 21 February – Mohan Bdr. Chand is at the sharp end of glacier research. A climate researcher at Kathmandu University, Chand is carrying out vital field work, looking at high mountain glaciers as indicators of climate change.

The work involves spending time clambering up and down the ice, taking measurements and readings to calculate mass balance – the sum of the snowfall which builds up on a glacier and the melting that shrinks it.

“Getting to a glacier can take five days from Kathmandu – two days driving and three days trekking”, says Chand, one of only a few native glacier specialists in Nepal. “We stay on the glacier for over two weeks at heights of between 5,000 and 6,000 metres. Conditions are tough, with altitude sickness a big problem.

“What we’re seeing is that almost all glaciers in Nepal are in retreat”, says Chand. “There are a few in the far west of the country which appear to be stable or increasing in size, but these – influenced by westerly winds rather than the Indian monsoon – are very much the exception.”

Calculating mass balance is seen as critical to understanding a glacier’s long-term behaviour. According to a 2011 study by the Kathmandu-based International Centre for Integrated Mountain Development (ICIMOD), there are an estimated 54,000 individual glaciers in the Hindu Kush-Himalayan region, an area of mountains stretching from Afghanistan in the west to Yunnan in southwest China in the east.

“The glaciers in much of the region show signs of shrinking, thinning and retreating”, said the study.

What is noteworthy is how little detailed knowledge there is of this region, which is considered to be highly vulnerable to climate change and to be warming faster than many other areas on the planet.

Retreat rates vary

 

“A serious lack of reliable and consistent data severely hampers scientific knowledge about the state of Himalayan glaciers”, said a late 2012 report by the United Nations Environment Programme’s global environmental alert service.

The region has been referred to as a “white spot”, a term in the 2007 IPCC (Intergovernmental Panel on Climate Change’s) Fourth Assessment Report used to describe an area with “little or no data”.

Confusion was added to the debate when, in the same IPCC report, it was suggested that the probability of  the Himalayan glaciers disappearing by 2035 “is very high if the Earth keeps warming at the present rate.”

It was a claim the IPCC later said should never have been published, but one that was eagerly seized on by climate sceptics in efforts to try to undermine the whole body of the Panel’s work.

Mohan and his team are investigating two glaciers – one at Rikhashambha in north-central Nepal at 6,000 metres, described as a valley glacier, and one at Yala to the east, on the border with Tibet at between 5,100 and 5,700 metres, described as a plateau-type glacier.

“In general plateau-type glaciers – mostly found in Tibet – seem to be retreating faster than valley types”, says Dr Mohan. “The number of glacial lakes at high altitudes is increasing, with between 20 and 26 in Nepal. If these burst, they pose a serious danger.

“Rising temperatures and sudden rainfalls of great intensity are factors that seem to be causing the retreat of some glaciers. But recently it’s been realised that black carbon could have a major impact on the mass balance of glaciers.”

Black carbon – particulate matter that in South Asia comes mainly from the burning of wood and waste and from cooking fires, or from coal-burning and diesel exhausts – falls on snow and darkens the surface, in the process reducing reflectivity and causing the surface to absorb more heat.

Data too sparse

 

Most of the black carbon falling on the Himalayas and the south of the Tibetan plateau comes from the plains of India, while that of the eastern and northern sections of the plateau comes mainly from China.

According to recent ICIMOD estimates, black carbon is probably responsible for a large part – around 30% by some calculations – of glacial retreat in the region.

ICIMOD and other bodies admit there is far too little field data available to draw solid conclusions, whether on overall glacial melt or on the influence of black carbon. Part of this is to do with the inhospitable terrain. Also, in a tense region where transboundary cooperation is severely limited, studies that have been done often use differing methodologies.

Advances in satellite technology have significantly increased the volume and quality of data gathering across the region. However, satellite survey results have shown considerable variation, with one survey finding large glacial retreat and another a much smaller rate of melt. Scientists say there is often no substitute for fieldwork but admit that the extent of such activity is still woefully inadequate.

“We will return to the glaciers in May to take more measurements”, says Chand. It is gruelling work but needs to be done if a full picture of what’s going in the glaciers of the Himalayas is to emerge. – Climate News Network

Soot fingered as climate threat

FOR IMMEDIATE RELEASE A study has found that black carbon, often called soot, is damaging the climate more than researchers had realised, and that cutting emissions could help to lower global temperatures. LONDON, 16 January – Climate scientists have just conceded that they may have been wrong about one aspect of man-made climate change – they have underestimated the dangerous impact of fumes from diesel exhausts and other sources of soot. Black carbon, as soot is also known, could be twice as bad as previously estimated as an agent of global warming. The news comes in an exhaustive, 232-page study published in the Journal of Geophysical Research – Atmospheres, written by 31 scientists from the US, Europe, Japan, China and India. They calculate that, in various ways, black carbon has a warming effect of 1.1 watts per square metre. This makes it two-thirds as influential as the principal man-made greenhouse gas, carbon dioxide. So the second biggest contributor to the global atmospheric crisis is soot. Soot has, say the scientists of the International Global Atmospheric Chemistry Project, “a unique combination of physical properties.” It strongly absorbs visible light, it is insoluble in water and it sticks around for a long time. It comes from the burning of coal and wood and dung in Africa and Asia, while diesel engines provide most of the black carbon in the air above Europe, North America and Latin America. The researchers reckon that 7.5 million tonnes a year of black carbon could be dumped in the atmosphere from power stations, cooking stoves, diesel engines and forest fires, although they also concede that total emissions are difficult to measure precisely. Black carbon was blamed for a sudden, dramatic melting of Greenland’s ice in the summer of 2012: the source of the soot was wildfires in the Arctic tundra.

“…we need to tackle air pollution and climate change as one joined-up problem.”

The research is a reminder that alarm about atmospheric pollution by human action is not new: soot was a component of notorious urban smog that ultimately claimed hundreds of thousands of lives in the great European cities each year before the introduction of clean air legislation. According to the World Health Organisation, the smoke just from cooking stoves in the developing world probably contributes to two million deaths from respiratory diseases every year. So there have always been reasons for worrying about black carbon.  But its role as a component of global warming has not been seriously and publicly addressed until now. The tiny spheres of dark carbon absorb the heat from the sun, can affect cloud formation, and smear and darken the surface of snow and ice, to accelerate warming and melting. Black carbon is now seen as a significant cause of rapid warming in the mid- to high latitudes of the northern hemisphere, but it can also trigger changes in the patterns of monsoon rainfall in the tropics. So the reduction of emissions could reduce both the risk of respiratory diseases and the rate of climate change in a large region of the globe. “If we did everything we could to reduce these emissions we could buy ourselves up to half a degree (Celsius) less warming – or a couple of decades of respite,” said Piers Forster of the University of Leeds in the UK, one of the co-authors. But, he warned, the solution was not straightforward: black carbon is not the only product from fire, and some discharges from burning vegetation might instead have a cooling effect. Alastair Lewis, an atmospheric chemist at the University of York, UK, who is not one of the research team, said: “This new study helps us see the bigger picture: that we need to tackle air pollution and climate change as one joined-up problem.” – Climate News Network

FOR IMMEDIATE RELEASE A study has found that black carbon, often called soot, is damaging the climate more than researchers had realised, and that cutting emissions could help to lower global temperatures. LONDON, 16 January – Climate scientists have just conceded that they may have been wrong about one aspect of man-made climate change – they have underestimated the dangerous impact of fumes from diesel exhausts and other sources of soot. Black carbon, as soot is also known, could be twice as bad as previously estimated as an agent of global warming. The news comes in an exhaustive, 232-page study published in the Journal of Geophysical Research – Atmospheres, written by 31 scientists from the US, Europe, Japan, China and India. They calculate that, in various ways, black carbon has a warming effect of 1.1 watts per square metre. This makes it two-thirds as influential as the principal man-made greenhouse gas, carbon dioxide. So the second biggest contributor to the global atmospheric crisis is soot. Soot has, say the scientists of the International Global Atmospheric Chemistry Project, “a unique combination of physical properties.” It strongly absorbs visible light, it is insoluble in water and it sticks around for a long time. It comes from the burning of coal and wood and dung in Africa and Asia, while diesel engines provide most of the black carbon in the air above Europe, North America and Latin America. The researchers reckon that 7.5 million tonnes a year of black carbon could be dumped in the atmosphere from power stations, cooking stoves, diesel engines and forest fires, although they also concede that total emissions are difficult to measure precisely. Black carbon was blamed for a sudden, dramatic melting of Greenland’s ice in the summer of 2012: the source of the soot was wildfires in the Arctic tundra.

“…we need to tackle air pollution and climate change as one joined-up problem.”

The research is a reminder that alarm about atmospheric pollution by human action is not new: soot was a component of notorious urban smog that ultimately claimed hundreds of thousands of lives in the great European cities each year before the introduction of clean air legislation. According to the World Health Organisation, the smoke just from cooking stoves in the developing world probably contributes to two million deaths from respiratory diseases every year. So there have always been reasons for worrying about black carbon.  But its role as a component of global warming has not been seriously and publicly addressed until now. The tiny spheres of dark carbon absorb the heat from the sun, can affect cloud formation, and smear and darken the surface of snow and ice, to accelerate warming and melting. Black carbon is now seen as a significant cause of rapid warming in the mid- to high latitudes of the northern hemisphere, but it can also trigger changes in the patterns of monsoon rainfall in the tropics. So the reduction of emissions could reduce both the risk of respiratory diseases and the rate of climate change in a large region of the globe. “If we did everything we could to reduce these emissions we could buy ourselves up to half a degree (Celsius) less warming – or a couple of decades of respite,” said Piers Forster of the University of Leeds in the UK, one of the co-authors. But, he warned, the solution was not straightforward: black carbon is not the only product from fire, and some discharges from burning vegetation might instead have a cooling effect. Alastair Lewis, an atmospheric chemist at the University of York, UK, who is not one of the research team, said: “This new study helps us see the bigger picture: that we need to tackle air pollution and climate change as one joined-up problem.” – Climate News Network