Climate Change: Scientists alarmed over ‘dangerously fast’ spike in atmospheric methane – Report

Methane concentrations in the atmosphere raced past 1,900 parts per billion last year, nearly triple preindustrial levels, according to data released in January by the U.S. National Oceanic and Atmospheric Administration (NOAA).

A report by Nature Briefing on Tuesday also noted how scientists believe the grim milestone underscores the importance of a pledge made at last year’s COP26 climate summit to curb emissions of methane, a greenhouse gas at least 28 times as potent as CO2.

Slow growth

The growth of methane emissions slowed around the turn of the millennium, but began a rapid and mysterious uptick around 2007, the report recalled.

The spike has caused many researchers to worry that global warming is “creating a feedback mechanism that will cause ever more methane to be released, making it even harder to rein in rising temperatures.”

“Methane levels are growing dangerously fast,” said Euan Nisbet, an Earth scientist at Royal Holloway, University of London, in Egham, UK, according to the report.

The emissions, which seem to have accelerated in the past few years, are a major threat to the world’s goal of limiting global warming to 1.5–2 °C over pre-industrial temperatures, he added.

Nigeria’s attempt to curb methane

Nigeria recently sought to reduce short-lived climate pollutants (SLCPs), by committing to slash black carbon, methane, and hydrofluorocarbons (HFCs) in its Nationally Determined Contributions (NDCs), or its internationally agreed-upon commitment to mitigating climate change.

The country included an SLCP section with a 60 per cent reduction in “fugitive methane emissions from the oil and gas sector by 2031, conditional on international support”.

If these NDCs are fully achieved, black carbon are expected to reduce by 42 per cent, methane by 28 per cent, and HFCs by 2 per cent, all by 2030.

The Nigerian government had recognised the International Intergovernmental Panel on Climate Change (IPCC) conclusion that there is no way to limit global warming to 1.5 degrees Celsius “without significant SLCP reductions alongside carbon cuts.”

Africa has been hit with debilitating effects of climate change in recent years. Such effects include increased food insecurity, rising sea levels, floods, worsening droughts, and exacerbated conflict worsened by forced displacements.

Experts believe climate change will ultimately negatively affect food production in this west African nation where agriculture accounts for 23 per cent of the country’s gross domestic product and where over 40 per cent of the population is “food insecure”.

‘Enigmatic patterns’

Meanwhile, the report noted that for more than a decade, researchers have deployed aircraft, taken satellite measurements and run models in an effort to understand the drivers of the increase in methane.

“The causes of the methane trends have indeed proved rather enigmatic,” said Alex Turner, an atmospheric chemist at the University of Washington in Seattle. Mr Turner, quoted in the report, said he is yet to see any conclusive answers emerge.

“It’s a powerful signal,” said Xin Lan, an atmospheric scientist at NOAA’s Global Monitoring Laboratory in Boulder, Colorado, adding that this suggests that human activities alone are not responsible for the increase.

Mr Lan’s team has used the atmospheric 13C data to estimate that microbes are responsible for around 85 per cent of the growth in emissions since 2007, with fossil-fuel extraction accounting for the remainder.

Global Methane Pledge

Experts agree that a lot can be done to reduce emissions.

Despite NOAA’s worrying alarm for 2021, “scientists already have the knowledge to help governments take action”, said Riley Duren, who leads Carbon Mapper, a non-profit consortium in Pasadena, California, that uses satellites to pinpoint the source of methane emissions.

Last month, for instance, Carbon Mapper and the Environmental Defense Fund, an advocacy group in New York City, released data revealing that 30 oil and gas facilities in the southwestern United States have collectively emitted about 100,000 tonnes of methane for at least the past three years, equivalent to the annual warming impact of half a million cars.

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These facilities could easily halt those emissions by preventing methane from leaking out, the groups argue.

At COP26 in Glasgow, UK, more than 100 countries signed the Global Methane Pledge to cut emissions by 30 per cent from 2020 levels by 2030.

Mr Duren said the emphasis must now be on action, including in low- and middle-income countries across the global south.

“Tackling methane is probably the best opportunity we have to buy some time,” he said, to solve the much bigger challenge of reducing the world’s CO2 emissions.