Falling sulfur dioxide emissions in the United States are expected to substantially increase rainfall in Africa’s semi-arid Sahel, while bringing slightly more rain to much of the U.S., according to a new study in the Journal of Geophysical Research: Atmospheres.

Pollution filters placed on coal-fired power plants in the United States starting in the 1970s have dramatically cut emissions of sulfur dioxide, a toxic gas that contributes to acid rain and premature deaths from respiratory and cardiovascular diseases. If U.S. sulfur dioxide emissions are cut to zero by 2100, as some researchers have projected, rainfall over the Sahel could increase up to 10 percent from 2000 levels, computer simulations published in the study suggest.

The wildfire that has raged across more than 150,000 acres of the Okefenokee Swamp in Georgia and Florida has sent smoke billowing into the sky as far as the eye can see. Now, new research published by the Georgia Institute of Technology shows how that smoke could impact the atmosphere and climate much more than previously thought.

Researchers have found that carbon particles released into the air from burning trees and other organic matter are much more likely than previously thought to travel to the upper levels of the atmosphere, where they can interfere with rays from the sun – sometimes cooling the air and at other times warming it.

An international team of researchers has uncovered the mechanism that allowed Volkswagen to circumvent U.S. and European emission tests over at least six years before the Environmental Protection Agency put the company on notice in 2015 for violating the Clean Air Act. During a year-long investigation, researchers found code that allowed a car’s onboard computer to determine that the vehicle was undergoing an emissions test. The computer then activated the car’s emission-curbing systems, reducing the amount of pollutants emitted. Once the computer determined that the test was over, these systems were deactivated.

High levels of air pollution over time may get in the way of a good night’s sleep, according to new research presented at the ATS 2017 International Conference.

“Prior studies have shown that air pollution impacts heart health and affects breathing and lung function, but less is known about whether air pollution affects sleep,” said lead author Martha E. Billings, MD, MSc, assistant professor of medicine at the University of Washington. “We thought an effect was likely given that air pollution causes upper airway irritation, swelling and congestion, and may also affect the central nervous system and brain areas that control breathing patterns and sleep.”

Contemporary pollutants can reach deep wells that tap fossil aquifers, says a study by an international team of researchers.

Growing plants and then storing the CO2 they have taken up from the atmosphere is no viable option to counteract unmitigated emissions from fossil fuel burning, a new study shows. The plantations would need to be so large, they would eliminate most natural ecosystems or reduce food production if implemented as a late-regret option in the case of substantial failure to reduce emissions. However, growing biomass soon in well-selected places with increased irrigation or fertilization could support climate policies of rapid and strong emission cuts to achieve climate stabilization below 2 degrees Celsius.

Removal of polluted sediment from lake and river bottoms can be costly and time consuming. Ohio Sea Grant researchers are developing a new method using ultrasound and chemical agents that bind to contaminants and render them inactive on the river bottom. The new approach means larger quantities of sediment can be scrubbed more thoroughly with each round of treatment, potentially making pollutant clean up faster and less costly. The overall goal is to treat contaminated sediments right where they are instead of having to dredge them up for treatment or disposal.

Planting trees is a popular strategy to help make cities “greener,” both literally and figuratively. But scientists have found a counterintuitive effect of urban vegetation: During heat waves, it can increase air pollution levels and the formation of ozone. Their study appears in ACS’ journalEnvironmental Science & Technology.

Previous research has shown that planting trees in cities can have multiple benefits, including storing carbon, controlling storm water and cooling areas off by providing shade. This has spurred efforts in cities across the U.S. and Europe to encourage the practice. However, it’s also known that trees and other plants release volatile organic compounds, or VOCs, that can interact with other substances and contribute to air pollution. And when it’s hot, plants release higher levels of VOCs. Galina Churkina and colleagues wanted to investigate what effects heat waves and urban vegetation might have on air pollution.

At the Maji Agricultural Reservoir in Wonju, Gangwond-do, South Korea, that someone is Tae Kwon Lee. Lee regularly jogs around the reservoir. One day he noticed large black birds completely covering the small island in the lake. The black birds were great cormorants, a type of large water bird, and the trees on the islet were completely covered in the birds’ feces. As time passed, Lee made another observation: the lake suffered a severe algal bloom.

Algal blooms deplete oxygen in lakes, produce toxins, and end up killing aquatic life in the lake. This sequence of events got Lee wondering: Did the bird feces cause or contribute to the algal bloom?

The study, just published in the journal Atmospheric Environment, points out that low hedges reduce the impact of pollution from vehicles in cityscapes where there are large buildings close to roads, far more effectively than taller trees. In some environments, trees actually make the pollution more concentrated depending on prevailing wind conditions and built-up configurations.