Forest fire emissions ‘poisoning Arctic environment’


Forest fires and straw and stubble burning in North America and Eastern Europe are leading to record-high concentrations of the environmental toxin PCB over the Arctic island of Svalbard, a report warns.

Take Cover library imageOver the past decades, persistent organic pollutants (POPs) have been found in large concentrations in Arctic areas.

These substances accumulate in living organisms and are enriched throughout the food chain.

Polychlorinated biphenyl (PCB) is one of the most important environmental toxins of this type.

“We wanted to draw attention to the causes of the environmental impact in the Arctic and trace the sources of the problem,” said Sabine Eckhardt, a researcher at the Norwegian Institute for Air Research (NILU).

When biomass from trees and dead grass and leaves catches fire, it releases both PCB and other environmental toxins and creates yet another source of PCB emissions.

In 2004 and 2006, big fires ravaged these areas. About 5.8m hectares of coniferous forest burned down in North America, while Eastern Europe experienced extensive emissions from agriculture due to straw and stubble burning.

Several weeks later, the researchers found record-high values of PCB in the atmosphere above Svalbard.

“As far as we know, this is the first study that shows a connection between the burning of biomass and PCB concentrations in the atmosphere far away,” said Sabine Eckhardt.

“With a climate that is constantly changing, we expect the extent of such fires to increase.

“In such case, it also means that the fires may represent an increasing environmental problem in the Arctic.

“That in turn will reduce the effect of the international agreements that aim to reduce emissions of these environmental toxins,’ said Ms Eckhardt.

PCB is a group of synthetically-produced persistent toxic compounds., and can be stored in the fatty parts of the organism and accumulates in the food chain.

Humans, fatty fish and carnivores (such as polar bears) can therefore accumulate concentrations in their bodies that are so high that they are poisoned.

As the primary emissions of organic environmental toxins are reduced, the researchers believe that fires caused by climate change will become more important.

They point to the fact that there has been little focus on the significance of burning biomass, and the potential consequences of this for the Arctic environment.

“For the first time, we have proved that burning biomass is also an important source of persistent organic pollutants in polar areas,” Ms Eckhardt observed.

“This can be of great importance to international agreements that aim to protect the environment in Arctic areas.”

Source: The Research Council of Norway

Date: 31/05/2010

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Human activity ‘triggers rise in Borneo forest fires’


Severe fires in Indonesia – responsible for some of the worst air quality conditions worldwide – are linked not only to drought, but also to changes in land use and population density, according to a new study in Nature Geoscience.

“During the late 1970s, Indonesian Borneo changed from being highly fire-resistant to highly fire-prone during drought years, marking the period when one of the world’s great tropical forests became one of the world’s largest sources of pollution,” said lead researcher Robert Field, a PhD student of atmospheric physics at the University of Toronto, Canada.

“Ultimately, this abrupt transition can be attributed to rapid increases in deforestation and population growth,” he explained.

“The resulting occurrences of haze currently rank among the world’s worst air pollution episodes, and are a singularly large source of greenhouse gas emissions.”

Sumatra has suffered from large fires since at least the 1960s, but Indonesian Borneo seems to have been resistant to large fires, even in dry years, until population density and deforestation increased substantially and land use changed from small-scale subsistence agriculture to large-scale industrial agriculture and agro-forestry.

“We’ve had a good understanding of fire events since the mid 1990s, but little before this due to the absence of fire data from satellites,” said Mr Field.

“However, one of the major impacts of large-scale fires is a reduction in visibility due to the smoke produced.

“Visibility is recorded several times a day at airports in the region, and these records proved to be an excellent indicator of severe fire activity.

“We were able to piece together visibility observations back to the 1960s, and hence develop a longer term record of the fires.”

Having a long-term record of the fires allowed the scientists to better understand their causes.

“Using weather records, we were able to estimate the specific rainfall level below which large fires have occurred in the previous two decades,” Mr Field added.

“In turn, we found that the rainfall over Indonesia was influenced equally by the Indian Ocean Dipole and the El Nino Southern Oscillation phenomena.”

Mr Field concluded: “Hopefully, this information can be used to better anticipate and prevent future haze disasters in Indonesia.”

He said that there was a direct link between the increased prevalence of severe fires and haze disasters and the man-made change in land use.

“The visibility record also showed, quite strikingly, the impact of human settlement on a previously pristine tropical forest.

“This should give pause to further agro-forestry expansion in Indonesia, particularly for oil palm as a source of biofuel.”

Source: EurekAlert

Date: 22/02/2009

Report: Trees in the urban realm


Although the findings from the UK’s Tree and Design Action Group were published in 2008, it is worth reprising here.

The group, comprising of professionals and organisations, looked at the threat facing urban trees, while highlighting the benefits they bring to local communities.

It says that trees enrich the urban landscape by “improving health and well-being for people and the environment”.

It goes on to say that the report also highlights that urban trees mitigate temperature extremes, reduce pollution and increase real estate values.

“In terms of climate change,” the group suggests, “trees have been identified as being a key element of any urban climate change adaptation strategy.

“Trees are uniquely placed to be widely integrated into the urban fabric, providing a shading and cooling mechanism.

“Without this cooling mechanism, cities of the future – London in particular – are likely to be very inhospitable places.”

However, the group says that while there is awareness about the role trees can play in making cities habitable in the future, current design and planning systems make it very difficult to plan for the future.

“The services and infrastructure needed in cities to achieve high densities living generally militates against the presence of trees.

“Climate change will add to these pressures and create a landscape devoid of large trees unless practical steps are taken by a range of professional bodies working in partnership.”

It builds on the London Assembly Environment Committee’s 2007 report “Chainsaw Massacre“, which highlighted the loss of street trees in London. It found that more large tree species were being cut down rather than being replaced.

The Trees in Towns II report, commissioned by the Department for Communities and Local Government, echoed this findings for the rest of England.

Source: Trees and Design Action Group (TDAG)

Date: December 2008

Africa’s urban trees are casualties of overcrowded cities


It is not only the rural regions in developing nations that are losing tree cover.

In an article published by the Ugandan website, New Vision, environmental journalist Ebenezer Bifubyeka highlights the issue of urban trees being felled.

The reason? Apparently, it is because of the rising population in cities, which is increasing the demand for urban open spaces to be converted into housing.

In his article, reproduced below, he highlights why authorities’ decisions to sacrifice the green urban spaces are is not without consequence:

On January 2, The New Vision published an article quoting the director of Natural Resources in the National Forestry Authority, Hudson Andura, as saying:

“Fifteen urban forest reserves are to be degazzated to cater for the growing population and development in 15 towns countrywide.”

Do we ever ask ourselves why trees stand side by side with skyscrapers in cities within developed countries? The reason is to mitigate city noise and absorb pollutant gases. Trees reduce on noise and absorb toxic gases.

The move by the National Forest Authority to degazzate forest reserves in 15 towns is not only a miscalculation but also a disastrous move. It is in urban centres that greenhouse gases are most emitted from factories and trees are the immediate reducers of such pollutant gases.

Is anybody bothered about the loss of national tree cover from 28% in 1988 to 13% by 2008? The loss of water catchment areas has led to poor and filthy water quality, thus the subsequent deaths of fish.

Besides, ornamental and ambient roles, trees in urban compounds, streets, recreational centres and hospitals keep the cycle of air flow fresh. In public hospitals like Mbarara Hospital, there used to be enough shed trees purposely to reduce noise of vehicles for the sick. It is unfortunate that these trees are being felled.

Trees reflect noise upwards in the atmosphere, according to Jeconious Musingwire, the western regional environment awareness officer.

As Uganda moves towards development circles, we have started going more brown (non-green environment). Despite pressure from investors and politicians to develop urban areas, development should be in harmony with conservation. Otherwise, we shall head for desertification and famine.

The escalating global warming – evidenced by climate change – warns us to stop further degradation of other green belts such as swamps, parks, green grass and forests.

In this regard I implore the Government to take environment concerns seriously and discourage cementing pavements and compounds. The green grasses are vital, for they ease the percolation of water into the soil.

Source: New Vision website

Date: 14/01/2009

Trees ‘can cut emissions from poultry farms’


Planting just three rows of trees around poultry farms can cut nuisance emissions of dust, ammonia, and odours from poultry houses and help reduce complaints from neighbouring properties, US researchers suggest.

A Science Daily article quotes George Malone from the University of Delaware as saying the tree barrier can cut some of the emissions by almost a half.

Dr Malone presented his findings at the annual conference of the American Chemical Society (ACS).

The team of researchers said planting vegetation could reduce ammonia and particulates that may degrade surrounding air and water quality.

“We were aware of the concerns locally,” said Malone. “We looked at what we could do to address them and the whole area of air quality as it relates to the emission of ammonia from poultry houses.”

In response, they proposed planting trees to serve as a vegetative filter that could capture emissions from family-run farms, which can house an average of 75,000 chickens.

In their six-year study, Dr Malone and his team found that a three-row plot of trees of various species and sizes reduced total dust by 56% percent, ammonia by 53%, and odour levels were cut by about 18%.

However, Dr Malone added that certain tree species were more effective as barriers than others.

“We’ve certainly been on a learning curve since 2001 about the different plant materials suitable for this practice,” he said.

“We typically recommend the first row nearest the fans to be either a deciduous tree or a tree with a waxy leaf surface and the other two rows be an evergreen.

“It’s very important to realise there are a number of criteria that you use in tree selection and planting design. What works for our soil types and climate on the Delmarva Peninsula may not be suitable for other locations.”

The living filter system also has other benefits, the University of Delaware researcher noted.

For instance, it conserves energy by increasing shade and cooling in the summer and acts as a buffer to reduce heating costs in the winter.

Not only do trees enhance air quality, they also improve the water quality around poultry farms because they can filter pollutants from soil and groundwater.

Source: Science Daily

Date: 22/08/2008

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