Why are methane levels rising?

Scientists at the Askö research base in southern Sweden are investigating the rapid rise in methane levels in the atmosphere. While carbon dioxide (CO2) is a well-known greenhouse gas, methane is a more potent one, and its increase is of concern for climate scientists.

To address the mystery of rising methane levels, researchers are focusing on measuring natural sources of methane, particularly in coastal areas like the Baltic seascape around Askö.

Methane is emitted by both natural and human-made sources. The team in Sweden has placed chambers on the water surface to measure methane, carbon dioxide, and water vapor. They are particularly interested in identifying which coastal habitats are significant sources of methane. Understanding how much methane is coming from lush coastal regions is essential in solving the broader question of why methane levels are increasing.

Traditionally, it was believed that methane emissions primarily occurred in tropical and low-latitude regions. However, scientists have noticed that higher-latitude environments, like the Swedish coastal areas, share characteristics conducive to methane production. These areas have dense vegetation belts, warm summer temperatures, and potentially emit significant amounts of methane, which hasn’t been thoroughly considered in methane budgets.

Methane emissions come from three main sources: industries like oil and gas, agriculture and waste, and natural processes. The recent rise in methane levels needs more investigation into natural sources. While some human-made sources, such as agriculture and sewage treatment plants, are known to be strong emitters, the contributions of coastal regions, lakes, rivers, wetlands, farmland, and forests are not well-monitored.

Researchers are concerned that as the planet warms due to climate change, methane-producing bacteria in various ecosystems are becoming more active, potentially leading to increased methane emissions. This positive feedback loop could accelerate global warming, given methane’s potency as a greenhouse gas.

To better understand the trends and identify sources of methane emissions, more comprehensive and better-funded monitoring efforts are required. While there is some monitoring of industrial emissions due to the economic value of methane, the sources in agriculture and natural environments remain relatively unknown. Preventing human-caused emissions is crucial because it can have a dual effect by reducing both current human emissions and future natural emissions of methane. Understanding the dynamics of methane in the atmosphere is essential to address climate change and mitigate its impact.

https://www.euronews.com/green/2023/10/16/methane-levels-are-rising-could-it-be-natures-response-to-warming