methane gas

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

When talking about the causes of climate warming, it is common practice to bundle together various pollutants and express their effects in terms of “CO2 equivalence.” This involves comparing climate effects of the pollutants on a 100-year timescale. Recent research from the Institute for Advanced Sustainability Studies in Germany points out the problems with this approach.

One of the worst qualities of carbon dioxide is that it accumulates in the atmosphere. Once it gets there, it stays there for anywhere from decades to millennia. On the other hand, short-lived climate forcing pollutants – or SLCPs – stay in the atmosphere for significantly shorter periods. However, some of these are far more effective at trapping heat in the atmosphere. As a result, the atmosphere and climate system react much more quickly to reductions in the emission of these pollutants.

The IASS research study determined that reducing SLCP emissions is an important way to slow near-term climate warming as well as having other positive benefits such as reducing air pollution and improving crop yields. A number of studies indicate that a rapid reduction in SLCP emissions could slow the rate of climate change and reduce the risk of triggering dangerous and potentially irreversible climate tipping points.

Examples of SLCPs are the methane gas emitted from landfills and hydrofluorocarbons that are still widely used as coolants. HFCs only persist in the atmosphere for 15 years but are nearly 4,000 times more effective in trapping heat over a 20-year period.

In order to mitigate the most harmful consequences of climate change, we need to minimize both the near-term climate impacts of SLCPs and the long-term climate impacts of carbon dioxide.

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More Than Just CO2: It’s Time To Tackle Short-Lived Climate-Forcing Pollutants

Photo, posted March 10, 2020, courtesy of Jonathan Cutrer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Methane And Wildfires | Earth Wise

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Short-Lived Climate Forcing Pollutants | Earth Wise

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