Methane's Contribution to Global Warming
Sat, April 10, 2021

Methane's Contribution to Global Warming



Earth is facing unprecedented rising of global temperatures, affecting all living organisms including humans. Multiple studies have shown that humans should be blamed for the worsening global warming on our planet. While it was reported that 95% of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations, all of these were caused by humans and their destructive activities. 

A 2016 study discovered that humans are responsible for virtually all of the observed global warming since the mid-20th century. Humans conduct activities that emit greenhouse gases that significantly impact our climate. For instance, carbon dioxide enters the atmosphere through burning fossil fuels, solid waste, trees, and other biological materials, while methane is emitted during the production and transport of coal, natural gas, and oil. 

The US Environmental Protection Agency reported that US greenhouse gas emissions in 2017 consist of carbon dioxide (82%), methane (10%), nitrous oxide (6%), and fluorinated gases (3%). Since carbon dioxide dominates our atmosphere the most, many scientists are focused on reducing this particular gas. But, recent studies show that we should also channel our focus to another gas that’s equally dangerous: methane.



The Rising Methane Emission

While carbon dioxide is much more evident in the atmosphere, methane is 84 times more potent than it. This means that it has far more devastating impacts on the climate because of how it effectively absorbs heat. It was reported that about 25% of manmade global warming we are experiencing is caused by methane emissions. 

The gas can come from many sources, both natural and manmade. A large source of manmade emissions is the oil and gas industry. It is also produced by cattle, decaying vegetation, fires, coal mines, and natural gas plants. According to The Conversation, a network of not-for-profit media outlets that publish news stories written by academics and researchers, methane leaks occur at every step and stage from production to distribution: production (37%), gathering (27%), transmission and storage (16%), processing (13%), and distribution (7%). 

Now, scientists are getting more worried than ever because atmospheric concentrations of methane continue to surge. In 2018, it climbed by 10.77 parts per billion, the second-highest annual increase in the past two decades. “What we are now witnessing is extremely worrying. It is particularly alarming because we are still not sure why atmospheric methane levels are rising across the planet,” Professor Euan Nisbet of Royal Holloway of the University of London said. 

A recent study, however, reported that many scientists have underestimated the methane levels in our atmosphere. According to Science Daily, an American website that aggregates press releases and publishes lightly edited press releases about science, the researchers from the University of Rochester measured methane levels in ancient air samples from Greenland. These samples contain air bubbles with small quantities of ancient air trapped inside, acting as time capsules. After that, the team used a melting chamber to extract the ancient air from the bubbles and then study its chemical composition.

The researchers needed to study the composition of air from the early 18th century to the present day because this would allow them to identify the natural emissions absent the emissions from fossil fuels that are present in today's atmosphere. They found out that methane emissions in the atmosphere have increased by approximately 150% over the past three centuries. "Methane is important to study because if we make changes to our current methane emissions, it's going to reflect more quickly,” author Benjamin Hmiel, a postdoctoral associate in the lab of Vasilii Petrenko, said. 



How Methane Contributes to Global Warming

Researchers have also warned that if methane levels keep increasing at current rates then the Paris climate deal’s goals would be very difficult to meet. According to NewScientist, a weekly English-language magazine that covers all aspects of science and technology, another factor that’s even more concerning is the fact no one is entirely sure what is driving the trend. 

“The fact that growth rates in the atmospheric concentrations of methane are approaching the levels we saw in the 1980s, after a period of relatively slow growth, is deeply concerning. The fact that we don’t understand the reasons for this surge deepen that concern,” Keith Shine at Reading University said. 

If methane is not contained over the next few years, it will only cause a far greater warming effect in the atmosphere than carbon dioxide. It would result in 86-fold more heating over 20 years and 35-fold more over a century. Thus, scientists are targeting methane through the fast implementation of technology to achieve reduced global warming. But, they need to find out first where and from what sources emissions are emitted. This could give policymakers strategies to contain methane and its contribution to global warming.



Study lead author Lena Hoglund-Isaksson explained that policymakers would need detailed inventories of the sources and locations of current human-made emissions, build scenarios for expected developments in future emissions, assess the abatement potential of future emissions, and estimate the costs of reducing emissions. However, the study discovered that without measures to control methane emissions, there would be a global emission increase of about 30% until 2050. 

Denise Mauzerall, a professor jointly appointed in civil and environmental engineering and the Woodrow Wilson School of Public and International Affairs, stated that controlling methane emissions is an effective way to slow global warming because it is very effective at trapping heat. At the same time, it has a relatively short lifetime of about a decade before it oxidizes to carbon dioxide. 

“The fastest way to reduce the effects of greenhouse gases significantly is by decreasing methane emissions. If we improve our practices right now and lower methane emissions, it will pay off quickly because the half-life of methane in the atmosphere is about a decade, and it wouldn’t take long for the current build-up to begin to clear,” Mark Zondlo, associate professor of civil and environmental engineering, said.