air pollutants

Methane And Wildfires | Earth Wise

May 29, 2023 By EarthWise Leave a Comment

Methane is a colorless and odorless gas that occurs abundantly in nature and is also a product of certain human activities. It’s also a potent greenhouse gas, meaning it affects climate change by contributing to increased warming. In fact, methane gas is known to warm the planet 86 times more effectively than carbon dioxide over a 20-year period.

According to the U.S. EPA, up to 65% of total methane emissions around the world come from the following human activities: raising livestock, leaks from natural gas systems, and waste from landfills.

Scientists from the University of California, Riverside have discovered that wildfires are releasing a massive amount of methane gas into the atmosphere. According to the research team, this source of methane is not currently being tracked by air quality managers in California. And this omission could have significant implications for climate change mitigation efforts in the state.

Methane from wildfires is nothing new. But what is new is just how much of the stuff is being emitted. According to the findings, which were recently detailed in the journal Atmospheric Chemistry and Physics, the amount of methane from the top 20 fires in 2020 was more than seven times greater than the average from wildfires in the previous 19 years. Wildfires were the third largest source of methane emissions in California in 2020.

In 2016, California passed a law requiring a 40% reduction in air pollutants contributing to global warming by 2030. But as wildfires continue to get bigger and more intense, achieving those reduction targets will get increasingly difficult.

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Methane from megafires: more spew than we knew

Detecting Methane

Photo, posted November 30, 2015, courtesy of Daria Devyatkina via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

The Importance Of City Trees | Earth Wise

January 28, 2022 By EarthWise Leave a Comment

It is well known that green spaces can improve the quality of life and create a better climate in cities. City trees and vegetation can help reduce urban heat island effects by shading buildings and roads, deflecting radiation from the sun, and releasing moisture into the atmosphere. City trees and green spaces have also been proven to increase property values, promote wildlife and plant diversity, reduce noise pollution, and improve human health. But how important are trees and vegetation for producing cleaner air in cities?

According to a new study led by researchers at the University of Gothenburg in Sweden, trees do contribute to cleaner air in cities, but the degree to which they do so varies greatly between different locations.

The research team measured air pollutants across seven urban settings in the city of Gothenburg, and compared them with pollutants on the leaves of deciduous trees. The researchers chose to focus on polycyclic aromatic hydrocarbons (PAHs), which are pollutants generated primarily during the incomplete combustion of organic materials, like coal, oil, and wood.

The results revealed that the pollutants in leaves did increase over time. The researchers were able to show a clear correlation between the level of air pollutants and the concentration of pollutants in leaves.

But at the same time, the researchers discovered that pollution levels varied greatly between measurement sites. For example, the levels of PAHs were seven times higher at the most polluted site (the city’s main bus station) than they were at a location on the periphery of the city.

The research team hopes its findings will be used to help guide the planning of future urban landscapes.

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Trees are important for cleaner air in cities

Photo, posted November 5, 2021, courtesy of Maria Eklind via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Benefits Of A Zero-Emissions Boston | Earth Wise

May 25, 2020 By EarthWise Leave a Comment

Many countries, states, and cities around the world have set goals to become carbon neutral, typically by the year 2050. These goals are based on the desire to mitigate the effects of climate change that are steadily increasing as a result of the buildup of carbon dioxide in the atmosphere. But reducing emissions is not just a way to combat climate change, it can also be a major contributor to improved public health.

The City of Boston has set a goal to become carbon neutral by 2050. A new study by the School of Public Health at Boston University published in the journal Environmental Research Letters looked at the consequences of eliminating fossil fuel emissions in the greater Boston area.

According to their modeling, eliminating emissions would save 288 lives a year by reducing fatal and non-fatal cardiovascular and respiratory illnesses. The resulting decrease in medical costs and lost and reduced work could save $1.7 billion a year in Suffolk County and $2.4 billion a year for the entire 75-square-mile zone modeled in the study.

The study looked at the amounts of two air pollutants known to harm human health: PM2.5 (particulates with a diameter of less than 2.5 microns) and ozone. They compared the current levels of these pollutants to what would be present when contributions from motor vehicles, generators, rail, industry, oil- and gas-burning, shipping and boating, and residential wood fires were eliminated.

The study focused on the City of Boston’s climate action plan, but actions taken by Boston will not take place in a vacuum. Many cities across the region are taking similar actions. The overall results will come from the collective actions across New England.

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A Zero-Emissions Boston Could Save 288 Lives and $2.4 Billion Annually

Photo, posted August 31, 2019, courtesy of Eric Kilby via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dangerous Smoke From Australia’s Wildfires | Earth Wise

January 13, 2020 By EarthWise Leave a Comment

Wildfires raging across Australia have devastated large swathes of land and prompted one of the largest evacuations in the country’s history. The fires, which have scorched approximately 20 million acres, have also killed 27 people and affected an estimated one billion animals at the time of this recording. The fire season, though still young, already ranks as among the worst in Australia’s recorded history.

Away from the flames, millions more in Australia are breathing unhealthy air as a result of the smoke from these wildfires. Wildfires release all sorts of dangerous air pollutants, like carbon monoxide and nitrous oxide. But wildfires also release fine particulate matter (more commonly referred to as PM2.5), which can be transported long distances. Breathing in these microscopic particles can lead to respiratory and cardiovascular problems. High levels of PM2.5 are particularly harmful to older people, young children, and those with weakened immune systems.

The Australian capital city of Canberra has been covered in a thick haze of smoke from nearby wildfires. Canberra recorded its worst air quality day on January 2nd, when levels of PM2.5 spiked to more than 200 micrograms per cubic meter during the worst hour.

Smoke has also been fouling Sydney’s air off and on for months, with PM2.5 readings hitting nearly 400 micrograms per cubic meter last month during the highest hour of pollution.

The U.S. EPA has in place an annual PM2.5 standard of 12 micrograms per cubic meter and a daily (or 24 hour) standard of 35.

According to the IPCC, southern Australia is expected to see increased risk of fire as the planet continues to warm. Regrettably, this could be the new normal.

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Millions of Australians Are Choking on Smoke From Wildfires

Photo, posted December 5, 2019, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Breathe Better With Air Conditioning

September 15, 2017 By EarthWise

For many people, commuting to and from work is a time-consuming, stressful part of their lives. In fact, the average American spends nearly an hour a day facing traffic jams and congested highways. There are direct health hazards in commuting as well. Drivers are exposed to increased amounts of air pollutants that have been linked to a wide range of medical problems including cardiovascular disease, respiratory issues and even lung cancer.