Acid rain can kill people

Acid rain keeps global warming in check

Sulfur counteracts methane emissions

Acid rain limits global warming by reducing methane emissions from natural wetlands. The science magazine New Scientist reports on a current study on this topic by the Open University in the UK. Acid rain is the result of industrial pollutant emissions that add small amounts of acidic components such as sulfuric and nitric acid to rainwater.

Polluted rainwater can interfere with the ecosystem of rivers and lakes, kill fish and other organisms, and damage plants, trees and buildings. The new study shows that the sulfur in acid rain also has advantages. By counteracting the natural production of methane gases by the microbes in the wetlands, it limits global warming. Methane accounts for around 22 percent of the man-made greenhouse effect.

The microbes in the wetlands are by far the largest methane producers. They deposit substrates such as hydrogen and acetate in the peat and in the methane emitted into the atmosphere. Global warming will continue to drive methane production by heating the microbes to produce even more methane. The new model assumes that sulfur pollution from industry will reverse this process. Experiments have shown that sulfur deposits reduce methane production by up to 30 percent, activating sulfur-eating bacteria.

"The study underscores the importance of including the whole earth system in the climate model," said Richard Betts, a climate expert from the Hadley Center for Climate Prediction and Research. “You have to observe the interaction between greenhouse gases and other effects on the biosphere.” Even so, acid rain remains a major problem for the environment. The study attempted to determine how sulfur pollution is affecting wetlands around the world. To do this, the experts created a computer model to simulate the interaction. The simulation took into account the latest data on global methane emissions and sulfur pollution, along with climate change models and data on the wetlands. “Basically, we investigated where wetlands and acid rain intersect,” says research director Vincent Gauci.

The model examined the interaction between sulfur pollution and natural methane emissions from wetlands between 1960 and 2080. "As early as 1960, methane was suppressed by sulfur pollution," said Gauci. The model also assumes that sulfur pollution will continue to suppress methane emissions, despite the feedback effect that global warming has on this process. The model predicts a reduction in methane emissions from the current eight percent to 15 percent in 2030 due to sulfur emissions. Sulfur pollution has already reduced methane emissions from wetlands from 175 to 160 million tons in 2001. Experts predict a further reduction to 155 million tons by 2030.

All news from the category: Earth sciences

The geosciences are fundamentally concerned with the earth and play a major role in the supply of energy and the general supply of raw materials.

Geosciences are joined by subjects such as geology, geography, geoinformatics, paleontology, mineralogy, petrography, crystallography, geophysics, geodesy, glaciology, cartography, photogrammetry, meteorology and seismology, early warning systems, earthquake research and polar research.

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