Methane levels reach an all-time high

Methane levels reached an all time high in 2019 after a near-record increase in the gas that’s 28 times more potent in the atmosphere than carbon dioxide.

The concentration of methane in the Earth’s atmosphere reached almost 1,875 parts per billion in 2019, up from 1,866 parts per billion in 2018 - according to the United States National Oceanographic and Atmospheric Administration (NOAA).

If confirmed later this year, it would be the second highest increase in methane levels for more than two decades. 

When considering greenhouse gases, the discussion is usually focused on potent carbon dioxide levels as the main culprit regarding global warming.

Methane may only be able to last in the Earth’s atmosphere for a few years, but it is 28 times more powerful than carbon dioxide at trapping the sun’s heat - which is why it is becoming an ever more significant factor in relation to the world’s global warming crisis. 

“We’re still waiting to see what the final number is going to be, and it’s going to be many months before we know that,” said Ed Dlugokencky, a research chemist at NOAA.

“But the fact that methane is increasing means it’s further contributing to climate change.”

Scientists warned last year that increasing methane levels will make it even harder to reach targets set by the Paris climate change agreement. 

Experts say that if methane levels continue to rise, the ability to limit temperature increases to 1.5-2 °C above pre-industrial levels will become even less realistic than previously thought.

“Last year’s (2019) jump in methane is one of the biggest we’ve seen over the past twenty years,” said Rob Jackson, professor of Earth system science at Stanford University and chair of the Global Carbon Project. 

“It’s too early to say why, but increases from both agriculture and natural gas use are likely. Natural gas consumption surged more than two percent last year.”

Controlling methane in the atmosphere

The key issue with methane is that its emissions are difficult to control. 

Methane emissions primarily come from natural sources, like wetlands, and manmade sources, like farms and oil and gas wells.

In wetlands, microbes excrete methane, which is an issue that humans can not do very much about.

The permafrost, any ground that remains completely frozen (-32°F (0°C) or colder) for at least two years consistently, stores large amounts of methane. As these grounds thaw at accelerating rates  due to climate change, this has a variety of consequences, including the release of methane.

In terms of human activities, several recent studies have shown that the increased levels of methane concentrations in the atmosphere are largely down to agriculture and livestock farming. Issues such as organic matter rotting in rice fields, methane generated in the digestive system of animals, storing in large amounts of manure, etc. are all identified as contributing factors. 

The primary focus for research has been meat production, with evidence suggesting that reduced consumption in Western countries would have many benefits for both human health and the environment. 

“Eat less beef and less dairy. That’s the most straightforward thing. For the sake of our own health, we should be doing that anyway”, said Drew Shindell, a climate scientist at Duke University. 

Meat production remains a complex and contested issue, because of its importance in other areas of the globe including developing countries. Some argue that a reduction in meat consumption could compromise food security for tens of thousands of people.

There are also anthropogenic sources of methane — leaks from global oil and gas production systems are a key source.

Grant Allen, an atmospheric physicist at the University of Manchester, told the Independent that “if we were to stop all natural gas use tomorrow we could reverse this”, as rising methane emissions were the sum total of natural and anthropogenic activity.

A recent study published in Nature found that methane leaks from the fossil fuel industry were underestimated by at least 40 per cent.

Shindell also suggests that the easiest way to stem methane pollution, is to limit its release from oil and gas drilling sites. Natural gas is mostly methane, and it is prone to leaking from wells. He said there are two key ways to deal with this problem. The first is to burn the natural gas that seeps out, which turns the methane into carbon dioxide. The second is to plug the leaks.

A paper published in the journal Nature Sustainability (May 2019), proposed a counter-intuitive solution: trapping methane from the atmosphere and converting it into carbon dioxide using zeolites, a type of porous material. Since methane has a much greater capacity to trap heat than carbon dioxide, in the medium term this approach could suppress one-sixth of global warming and gain some time to readdress climate change.