Climate: Tracking atmospheric aerosols

New satellite data shows volcanoes are a bigger factor than industrial emissions, at least high in the atmosphere

Alaska's Redoubt Volcano erupting in 1990. Photo courtesy USGS/R.J. Clucas.

Alaska’s Redoubt Volcano erupting in 1990. Photo courtesy USGS/R.J. Clucas.

By Summit Voice

FRISCO — Scientists have long known that aerosols can have a major effect on climate, and with measurements from sensitive satellite-based instruments, they’re getting a better handle on the formation, distribution and sources of various sulfur compounds in the atmosphere.

In a new study, researchers with the Karslruhe Institute of Technology say they’ve compiled one of the most comprehensive overview of sulfur dioxide measurements.

“Sulfur compounds up to 30 km altitude may have a cooling effect,” said KIT researcher Michael Höpfner, explaining that sulfur dioxide and water vapor react to sulfuric acid that forms aerosols, that reflect solar radiation back into universe. Continue reading

Study: Volcanic eruptions offset small part of greenhouse gas-driven global warming during the past 10 years

Researchers gaining a better understanding of stratospheric aerosols

Photo courtesy U.S. Fish and Wildlife Service.

Photo courtesy U.S. Fish and Wildlife Service.

By Bob Berwyn

FRISCO —A series of small to mid-sized volcanic eruptions the past 10 years were the main factor in the formation of stratospheric sulfuric acid that reflected the sun’s energy and partially offset the effects of heat-trapping greenhouse gases.

“This new study indicates it is emissions from small to moderate volcanoes that have been slowing the warming of the planet,” said Ryan Neely, a researcher at the Cooperative Institute for Research in Environmental Science and doctoral student at CU Boulder.

Neely said previous observations suggest that increases in stratospheric aerosols since 2000 have counterbalanced as much as 25 percent of the warming scientists blame on human greenhouse gas emissions. Continue reading

Environmental groups challenge EPA’s sulfur-dioxide emission exemptions for Southwest power plants

Fight over regional haze plans now at the federal appeals court level

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Conservation groups continue to fight for air pollution cleanup in the Southwest.

By Summit Voice

SUMMIT COUNTY — Clean Air Act loopholes in regional EPA-approved air quality plans are unacceptable, according to a coalition of environmental and community groups who last renewed their challenge to the regs in a Denver-based federal appeals court.

According to the groups, the plans allow coal-fired power plants in Utah, New Mexico and Wyoming to escape federal requirements to reduce their emissions of haze-causing pollutants. Of particular concern are exemptions for sulfur dioxide emissions, responsible for obscuring visibility and for significant human health impacts.

The exemptions are being challenged by HEAL Utah, National Parks Conservation Association, Powder River Basin Resource Council, and Sierra Club, represented by Earthjustice. Continue reading

Environment: Study tracks historic changes in atmospheric acidity in Greenland ice sheet

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A NASA satellite photo shows Greenland’s ice sheet.

Fossil fuels leave clear fingerprint

By Summit Voice

FRISCO — Researchers find all sorts of climate clues in Greenland’s ice sheet, and now, a new study of isotopes shows a distinct fingerprint of the long-term increase in atmospheric acidity.

The research by University of Washington researchers shows a decrease in levels of the isotope nitrogen-15 in core samples from Greenland ice starting around the time of the Industrial Revolution.

The decrease has been attributed to a corresponding increase in nitrates associated with the burning of fossil fuels. But the new evaluation links the decline increased acidity in the atmosphere — primarily from sulfur dioxide, which in the atmosphere is transformed to sulfuric acid, according Lei Geng, a UW research associate in atmospheric sciences. Following the Industrial Revolution, sulfur dioxide emissions increased steadily because of coal burning. Continue reading

Colorado clean-air plan gets early OK from EPA

A new clean air plan could help reduce the brown cloud over Colorado's Front Range and in national parks and wilderness areas in the region. PHOTO VIA UCAR.

Collaborative effort to cut power plant emissions gets bipartisan thumbs up

By Summit Voice

SUMMIT COUNTY —A state clean-air plan has a preliminary thumbs-up from the EPA, pending another round of public comment. The agency aims to finalize its decision by September.

A key component of the overall plan is the 2010 Clean Air-Clean Jobs Act passed by the Colorado General Assembly that will reduce harmful pollution through emissions controls; retire old, inefficient coal-fired power plants; and convert certain electric generating units from coal to cleaner-burning natural gas.

By 2018, the plan will result in more than 70,000 tons of pollutant reductions annually, including 35,000 tons of nitrogen oxides, which leads to ground-level ozone formation. In total, the plan covers 30 units at 16 facilities throughout Colorado, including coal-fired power plants and cement kilns. Continue reading

NASA satellite confirms air quality improvements

Sulfur dioxide emissions down by half since 2005

Darker areas indicate higher levels of sulfur dioxide.

By Summit Voice

SUMMIT COUNTY — Sulfur dioxide levels in the vicinity of major coal power plants in the Northeast have fallen by nearly half since 2005, according researchers studying data compiled by instruments on NASA’s Aura satellite.

The new findings confirm ground-based measurements of declining sulfur dioxide levels and demonstrate that scientists can potentially measure levels of harmful emissions throughout the world, even in places where ground monitoring is not extensive or does not exist.

The results of the study suggest that the EPA’s 2005 Clean Air Interstate Rule, calling for deep cuts in emissions, is working.

“What we’re seeing in these satellite observations represents a major environmental accomplishment,” said Bryan Bloomer, an Environmental Protection Agency scientist familiar with the new satellite observations. “This is a huge success story for the EPA and the Clean Air Interstate Rule,” he said. Continue reading

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