A Central New York congressman, seeing an opportunity that may never come again, has introduced a bill requiring the most drastic cuts in U.S. history to the pollution responsible for acid rain.

Rep. John McHugh said he wants to tie his "Acid Rain and Mercury Control Act" into a landmark energy and climate change bill that Congress will begin considering this week, with the goal of a vote by June. The climate legislation to control greenhouse gases received a boost last week when the U.S.

Environmental Protection Agency ruled that global warming is a danger to public health and welfare. The EPA's action sets the stage for the federal government to regulate carbon dioxide pollution and five other greenhouse gases linked to climate change.

But the EPA, and the separate global warming bill making its way through Congress, do not address all of the pollution from coal-fired power plants. The pollution contributes to acid rain, which has devastated lakes and forests in New York for decades. Among the pollutants that McHugh wants to target is mercury, which also poses a risk to human health.

McHugh, R-Pierrepont Manor, who proposed a similar bill to tackle acid rain in 2007, said he believes now is the best chance to finally solve the problem with federal legislation.

"One of the primary motivators for reintroducing the bill at this time is because of the debate surrounding climate change," McHugh said. "I didn't want acid rain to be left out."

Moderate increases in temperature and nitrogen from atmospheric pollution actually improve forest productivity. After more than 20 years of research in the northern hardwood forests of Michigan, scientists at Michigan Technological University's School of Forest Resources and Environmental Science have reached this surprising conclusion.

Andrew Burton, an associate professor at Michigan Tech and head of the National Institute for Climatic Change Research's Midwestern Regional Center, is part of a team of researchers that has been monitoring and measuring the temperature, moisture levels and nitrogen deposited by acid rain or varying levels of experimental nitrogen at four forest sites ranging from northwestern to southern Michigan since 1987. He's found that the trees grow faster at higher temperatures and store more carbon at greater concentrations of nitrogen, a chemical constituent of acid rain, providing there is sufficient moisture.

"It may well be that increasing temperature and nitrogen deposition are good things, up to a point," Burton said.

The rise in temperature is extending the growing season, he explained. So far, Burton and colleagues have measured 10 to 11-day longer growing seasons. "Our growing season isn't that long in the first place," he pointed out, "so 10 or 11 days is significant."

A longer growing season could benefit the timber industry, enabling them to harvest more wood. Now that woody biomass is being investigated as an alternative energy source by Michigan Tech and others, increased forest productivity could become a critical factor.

The research, which started out as an acid rain study in 1987, has grown into one of the longest continuous research studies supported by the National Science Foundation. A new five-year grant of $151,628 will fund the research through 2012.

"It is really unusual to receive NSF funding for nearly 20 years," Burton remarked.

The latest grant will fund ongoing measurements tree growth and the the build-up of organic matter in the soil at the four sites: near Twin Lakes in the northwestern Upper Peninsula of Michigan, at Pellston, near Petoskey, Mich., at Mesick, near Traverse City, and north of Grand Rapids near the Silver Lake Sand Dunes in southern Michigan.

Burton and his fellow researchers, Don Zak at the University of Michigan and Kurt Pregitzer at the University of Nevada-Reno, want to discover if the increased annual growth of the forests is offset by an increase in tree mortality. They also will examine whether the woody debris on the forest floor will decompose more slowly as nitrogen levels are increased, further increasing the ecosystem's ability to store carbon.

Burton calls the new work "a window into the future," an opportunity to see if there is a tipping point beyond which increased nitrogen harms rather than helps the forests.

Michigan Technological University is a leading public research university, conducting research, developing new technologies and preparing students to create the future for a prosperous and sustainable world. Michigan Tech offers more than 120 undergraduate and graduate degree programs in engineering, forestry and environmental sciences, computing, technology, business and economics, natural and physical sciences, arts, humanities and social sciences.

When an equal amount of sulphate (deposited by acid rain) was added, it reduced methane emission by 43 per cent.

Adding sulphate to soil in paddy fields is a popular method of controlling methane emission, to the tune of up to 70 per cent. In highly polluted countries such as India and China, acid rain also deposits a substantial amount of sulphate. This leads to more than required sulphate, which can be harmful for paddy. In such cases it becomes imperative to use sulphate sparingly, says a new study published in the Journal of Geophysical Research.

Vincent Gauci of the Department of Earth and Environmental Sciences, Open University, Milton Keynes, UK, simulated acid rain conditions and used it to reduce GHG emissions from paddy.

He found that the emissions reduced by 24 per cent during grain filling and the ripening stages of rice, which account for half the methane emissions in the cultivation period.

When an equal amount of sulphate (deposited by acid rain) was added, it reduced methane emission by 43 per cent.

"It is a known fact that sulphate is used to retard methane emissions but the paper overlooks several factors.

Both India and China are major paddy producers but the research has set acid rain levels in China as its benchmark. The levels in India are much lower and hence is not applicable here," explains C Sharma of National Physical Laboratory, New Delhi.

He adds that methane formation and its emissions are high where the soil is rich in organic carbon. "In India, the soil is poor in carbon. Moreover, since the research has been conducted only on the root system it fails to study the effect of acid rain on the leaves and the final crop. Besides, acid rain is disastrous for the ecology."

The research has also been criticised for being just an observation without going a step ahead to examine the impact of acid of cultivar. Sharma suggests that methane emissions could be controlled by proper water management and better drainage system in the rain fed areas.

WASHINGTON (Reuters) - To keep coral reefs from being eaten away by increasingly acidic oceans, humans need to limit the amount of climate-warming greenhouse gases in the atmosphere, a panel of marine scientists said on Wednesday. "The most logical and critical action to address the impacts of ocean acidification on coral reefs is to stabilize atmospheric carbon dioxide concentration," the scientists said in a document called the Honolulu Declaration, for release at a U.S. conference on coral reefs in Hawaii.

Ocean acidification is another threat to corals caused by global warming, along with rising sea levels, higher sea surface temperatures and coral bleaching, the scientists said.

Coral reefs are a "sentinel ecosystem," a sign that the environment is changing, said one of the experts, Billy Causey of the U.S. National Marine Sanctuary Program.

"Although ocean acidification is affecting the health of our oceans, the same thing -- increased carbon dioxide in the atmosphere -- is going to in fact be affecting terrestrial environments also," Causey said by telephone from Hawaii. Coral reefs offer economic and environmental benefits to millions of people, including coastal protection from waves and storms and as sources of food, pharmaceuticals, jobs and revenue, the declaration said.

But corals are increasingly threatened by warming sea surface temperatures as well as ocean acidification.

Oceans are getting more acidic because they have been absorbing some 525 billion tons of the greenhouse gas carbon dioxide over the last two centuries, about one-third of all human-generated carbon dioxide for that period. The carbon dioxide combines with sea water to form carbonic acid.

Marine researchers have long recognized acidification in deep ocean water far from land, but a study published this year in the journal Science found this same damaging phenomenon on the Pacific North American continental shelf from Mexico to Canada, and quite likely elsewhere around the globe.

The water became so corrosive that it started dissolving the shells and skeletons of starfish, clams and corals.

Stabilizing carbon dioxide emissions was the Honolulu Declaration's top long-term recommendation. The key short-term recommendation was to nurture coral reefs that seem to have natural resilience against acidification. This could be adopted immediately by managers of protected marine areas, Causey said.

The Honolulu Declaration will be presented to the United Nations and to other global, regional and national forums.

Acid rain caused by industrial pollution could actually help reduce the greenhouse gas emissions of agriculture, say scientists. Research led by the Open University's Dr Vincent Gauci suggests that sulphur-based acid rain from atmospheric pollution could cut the methane emissions associated with cultivating rice by almost a quarter.

Tonne for tonne, methane is more than 20 times more potent than carbon dioxide in terms of global warming.

Dr Gauci's findings suggest that, ironically, the high levels of pollution associated with China's rapid industrialisation may actually be going some small way towards mitigating its soaring CO2 output.

"Acid rain is one of several pollution problems in Asia that need solving in the coming decades but we need to appreciate the potential consequences of that clean up, one of which could be an increase in methane emissions as the effect of the acid rain wears off," said Dr Gauci.

"The reduction in pollution happens during a stage of the lifecycle when the rice plant is producing grain. This period is normally associated with around half of all methane emissions from rice and we found that simulated acid rain pollution reduced this emission by 24 per cent." said Dr Gauci.

The project , funded by the Natural Environment Research Council, used rice soils and grain from Portuguese paddies which have a similar chemical properties to Asian rice soils prior to their pollution.

To simulate acid rain experienced in polluted parts of China, the researchers added frequent small doses of sulphate.

"We need to do further research but it looks like there could be a combination of processes at work. One line of investigation we'd like to confirm is that the sulfate component of acid rain may actually boost rice yields," said Dr Gauci.

"This might, paradoxically, have the effect of reducing a source of food for the methane producing micro-organisms that live in the soil."

"There is also likely to be competition between these micro-organisms and sulphate-reducing bacteria. Normally in these conditions sulphate-reducers win which results in less methane."

This is not the first occasion where pollution has been shown to have a silver lining which goes some way towards offsetting its overall negative impacts.

Reducing smog in western Europe, for example, has improved air quality but potentially hastened warming, as the clouds of smog provided shading from the sun's rays.