The UK Government has revealed a year-on-year increase in the amount of sulphur dioxide emissions, which reverses a 40-year downward trend.

For the first time since the Seventies, official statistics show a small increase in the emissions of the sulphur dioxide of 2.3 per cent between 2009 and 2010.

The Defra report blamed the rise on a harsher winter and resulting increases in fuel consumption for heating and electricity generation.

However, the release pointed out that emissions of sulphur dioxide had still fallen by 89 per cent between 1990 and 2010, from 3.7 to 0.41 million tonnes.

The main source of sulphur dioxide (SO2) emissions is from combustion in energy production and transformation (58 per cent in 2010), followed by combustion in manufacturing industries (18 per cent in 2010).

It is these sources that have been the strongest drivers for the long term trend of falling emissions, by switching from coal to gas and improved efficiency.

Sulphur dioxide triggers chemical reactions in the atmosphere, which creates acidic air pollution which can cause harm to vegetation and buildings, including as acid-rain.

The report reveals the UK is still ahead of meeting current international targets to reduce emissions of sulphur dioxide and are 31 per cent below the lowest goal.

Article continues : http://www.clickgreen.org.uk/analysis/general-analysis/122960-after-40-year-decrease%2C-figures-show-rise-in-uk-acid-rain-pollution.html

A groundbreaking new study has found an increase in air pollution can reduce rainfall in drought-affected regions and worsen the severity of storms in wet regions or seasons.

Researchers have discovered that increases in air pollution and other particulate matter in the atmosphere can strongly affect cloud development in ways that reduce precipitation in dry regions or seasons.

This while increasing rain, snowfall and the intensity of severe storms in wet regions or seasons, according to results of a new study.

The research provides the first clear evidence of how aerosols - soot, dust and other particulates in the atmosphere - may affect weather and climate.

The findings have important implications for the availability, management and use of water resources in regions across the United States and around the world.

"Using a 10-year dataset of atmospheric measurements, we have uncovered the long-term, net impact of aerosols on cloud height and thickness and the resulting changes in precipitation frequency and intensity," says Zhanqing Li, an atmospheric scientist at the University of Maryland and lead author of a paper reporting the results.

The paper was published today in the journal Nature Geoscience.

Human use of Earth's natural resources is making the air, oceans, freshwaters, and soils more acidic, according to a U.S. Geological Survey — University of Virginia study available online in the journal, Applied Geochemistry. This comprehensive review, the first on this topic to date, found the mining and burning of coal, the mining and smelting of metal ores, and the use of nitrogen fertilizer are the major causes of chemical oxidation processes that end generate acid in the Earth-surface environment.

These widespread activities have increased carbon dioxide in the atmosphere, increasing the relative acidity of oceans; produced acid rain that has increased the acidity of freshwater bodies and soils; produced drainage from mines that has increased the acidity of freshwater streams and groundwater; and added nitrogen to crop lands that has increased the acidity of soils.

Although there are many mechanisms of global acidification, the focus in this new study is on the major ones, including emissions from combustion of fossil fuels and smelting of ores, mining of coal and metal ores, and application of nitrogen fertilizer to soils.

These widespread activities have resulted in:
(1) Increased CO2 concentration in the atmosphere that acidifies the oceans;
(2) Acidic atmospheric deposition that acidifies soils and bodies of freshwater;
(3) Acid mine drainage that acidifies bodies of freshwater and groundwaters;
(4) Nitrification that acidifies soils.

There are natural geochemical reactions of mineral weathering and ion exchange work to buffer acidification, the slow reaction rates or the limited abundance of reactant phases are not enough. Relatively recent modifications of resource extraction and usage in some regions of the world have begun to ameliorate local acidification, but expanding use of resources in other regions is causing environmental acidification in previously unnoticed places. In other words, some countries try to reduce these effects while others are more eager to expand and develop.

"We believe that this study is the first attempt to assess all of the major human activities that are making Earth more acidic," said USGS scientist Karen Rice, who led the study. "We hope others will use this as a starting point for making scientific and management progress to preserve the atmosphere, waters, and soils that support human life."

To examine the global impact of acidification, the researchers developed a series of world maps to show current coal use, nutrient consumption, and copper production and smelting by country. By combining this information with the anticipated population growth through 2050 and the impact of changing technology, regulations and other factors, the researchers address shifting trends in acidification.

"Looking at these maps can help identify where the current hotspots are for producing acidity, The population increase map can help guide policymakers on possible future trends and areas to watch for the development of new hotspots." said Rice.

For example, the populations of some countries in Africa are projected to increase in the near future. To support the growing populations, these countries likely will be forced to apply more nitrogen fertilizer to their crops than they currently use, increasing the acidification of soils and freshwater resources in a region that had not previously been affected.

To look at the impact of the acid producing activities, the researchers characterized the scale of environmental damage from major activities and their components as local, regional, global, or some combination of the three. Generating power by burning coal, for instance, can have local, regional and global impacts. Locally, it can cause acid mine drainage where the coal is mined; regionally, burning it can cause acid rain; globally, the increased carbon dioxide in the atmosphere increases the acidity of the ocean.

Acidification caused by acid rain precipitation has been, and remains, a major environmental issue because of its life-threatening effects on biota, its global spread, and the prolonged recovery period associated with it. International cooperation to reduce the precursors of acid precipitation has provided a textbook example of how society can address a complex environmental pollution problem with support from science. A key step in that success was the achievement of a broad scientific consensus that acid precipitation was a serious threat to ecosystems in sensitive regions. That consensus was built during two decades of scientific research starting with the first United Nations conference on the environment in 1972 and continuing to 1990 with the conclusion of major research programs in Europe and in the United States. But is this the only cause? A new study of the role of dissolved organic carbon, which comes from living organisms and can also make lakes acidic, suggests that power station emissions may have played less of a role than previously thought. Martin Erlandsson of the University of Reading, United Kingdom, and his colleagues wondered whether it was possible to distinguish the historical effects of organic acids and power station emissions by assessing findings during the 20 years since lake acidification started to decrease in Sweden. They describe their results in the August issue of BioScience.

Although there are few measurements of the amount of dissolved organic carbon in Swedish lakes before the 1980s, the amount of dissolved organic carbon in them has continued to increase despite the stabilization of power station emissions around 1990. The reason is unknown, but the increase supports the idea that as power station emissions increased during the 20th century they may have partly suppressed organic acidity in lakes that was present in pre-industrial times—at higher levels than when it was assessed in 1990.

Erlandsson and colleagues estimated the pre-industrial acidity of 66 lakes under different assumptions about the amount of dissolved organic carbon in them, and found that the assumptions had a large effect on estimates of how much the lakes had been affected by power station emissions. Studies of sediments in some of the lakes seem to bear out the idea that preindustrial organic carbon levels were at least as high as they are today—and considerably higher than they were in 1990. That in turn means the power station emissions did not contribute as much to lake acidification as was thought when liming programs were instigated.

The DOC concentrations in freshwaters vary over both historical and recent time scales. At present, there is no sign that the decadal trends of increasing DOC are abating in Sweden, even though sulfate concentrations in rain and surface waters are stabilizing. The results demonstrated in this study are not intended to imply that the question of what preindustrial DOC concentrations really were has been resolved, but rather to exemplify the significance of using different DOC reference levels.

Application of study technique to four lakes in southern Sweden indicates 15%—50% higher organic matter concentrations around 1850 relative to those in 2009. For two of these lakes, the reconstructed preindustrial DOC is actually sufficiently high for DOC suppression to completely compensate for acid deposition with no net change in the pH relative to preindustrial conditions. For the other two lakes, however, much higher DOC levels than what the paleolimnological reconstructions suggest are required for full pH compensation.

What this study shows is that acidification of a lake is a complex matter which is not yet clearly understood. Multiple cause may exists.

What are aerosols?

In this case they are tiny particles of dust, soot, salts, mist and all sorts of small stuff suspended in the air. This is what causes a hazy day, light scattering and sun light absorption. Aerosols have a great effect on climate but little is known about them.

Aerosols can be natural such as volcanic in source or manmade.

Some aerosols, particularly sulfate aerosols from fossil fuel combustion, exert a cooling influence (by the reflection or absorption of sunlight before it reaches the earth) on the climate which partly counteracts the warming induced by greenhouse gases such as carbon dioxide. Other effects are far from clear or known.

Recent studies of the Sahel drought and major increases since 1967 in rainfall over the Northern Territory, Kimberley, Pilbara and around the Nullarbor Plain have led some scientists to conclude that the aerosol haze over South and East Asia has been steadily shifting tropical rainfall in both hemispheres southward.

So now more than 60 scientists from a dozen institutions have converged on this California urban area to study how tiny particles called aerosols affect the climate. Sending airplanes and weather balloons outfitted with instruments up in the air, the team will be sampling aerosols in the Sacramento Valley June 2-28.

Researchers from the Department of Energy's Pacific Northwest National Laboratory in will be leading the month long study, coordinating air and ground operations at three sites in the Central Valley. The data they are collecting will help researchers improve computer models that simulate the climate and project climate changes.

To better understand aerosols' role in climate, the DOE's climate research program studies how aerosol particles in the air scatter and absorb the sun's radiation, and how much of it hits Earth.

The team of researchers will take daily measurements of trace gases and aerosols the city emits (known as the Sacramento urban plume) under relatively well defined and regular weather conditions. The knowledge gained will eventually be used in regional and global computer models that simulate the effects of aerosols on climate.

About half of the researchers will take measurements on the ground at two sites. The rest of the team will take similar measurements from the air flown on a Gulfstream-1 aircraft at about 1,000 feet. NASA will fly a King Air B-200 even higher at 28,000 feet.

In addition, the team will be sending weather balloons up for additional sampling from the ground sites. The simultaneous measurements from ground, plane and balloon will provide a comprehensive view of the atmospheric aerosols. From all this the scientists hope to piece together how the aerosols (and the various sub types of aerosols) affect the climate.