decomposing

Methane is a colorless and odorless gas that occurs abundantly in nature and is also a product of certain human activities. It’s a short-lived but highly potent greenhouse gas and, as a result, is a major driver of climate change. In fact, methane heats the atmosphere nearly 90 times faster than carbon dioxide over a 20-year period.

Despite a global pledge from more than 150 nations to reduce methane emissions by 30% this decade, methane emissions continue to rise. In fact, according to a new paper led by researchers from Stanford University, total annual methane emissions have increased 20% over the past two decades.

The paper, which was recently published in the journal Environmental Research Letters, found that atmospheric concentrations of methane today are more than 2.6 times higher than in pre-industrial times. In fact, atmospheric methane concentrations are currently the highest they’ve been in at least 800,000 years.

Methane emissions from coal mining, oil and gas production and use, cattle and sheep ranching, and decomposing organic waste in landfills are responsible for driving the growth. In 2020, the most recent year for which data was available, nearly 400 million tons – or about two-thirds – of global methane emissions came directly from human activities.

Methane concentrations in Earth’s atmosphere have increased at record speed over the past five years. According to the research team, only the European Union and possibly Australia seem to have decreased methane emissions from human activities over the past two decades. This trend “cannot continue if we are to maintain a habitable climate.”

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Methane emissions are rising faster than ever

Photo, posted December 4, 2010, courtesy of Dani Mettler via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

As the world seeks to reduce the greenhouse gas emissions that have been warming the climate, most of the focus has been on the primary contributors to the problem, such as the burning of fossil fuels. But there are many smaller contributors to greenhouse gas emissions that individually play only a minor role but collectively add up to significant amounts. One of these is the emissions from peatlands.

Peatlands are a type of wetland that occur in almost every country on Earth, covering 3% of the global land surface. They are terrestrial ecosystems in which waterlogged conditions prevent plant material from fully decomposing. As a result, the production of organic matter exceeds its decomposition, which results in a net accumulation of peat. Peatlands are, in fact, the largest natural terrestrial carbon store, storing more over 700 billion tons of carbon, more than all other types of vegetation combined.

Human activity, such as creating drainage in peatlands for agriculture and forest plantation, results in the release of over 1.6 billion tons of CO2 into the atmosphere each year. This constitutes 3% of all global greenhouse gas emissions caused by human activities.

Large numbers of people rely on peatlands for their livelihoods, so it is not reasonable for these emission-generating activities to be greatly curtailed. But researchers at the University of Leicester in the UK analyzed the potential effects of cutting the current drainage depths in croplands and grasslands on peat in half and showed that this could reduce CO2 emissions by more than 500 million tons a year. This equates to one percent of all greenhouse gas emissions caused by human activities.

There are numerous opportunities to reduce emissions a little bit at a time.

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Better peatland management could cut half a billion tonnes of carbon

Photo, posted August 17, 2013, courtesy of Joshua Mayer via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Rising methane emissions

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Peatlands And Greenhouse Gas Emissions | Earth Wise

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