Arctic methane levels reach new heights

Latest data released by a US institution, the NOAA Earth System Research Laboratory (ESRL), sounds afresh alarm bells for the Artic and climate change. It adds further evidence corroborating an earlier hypothesis that predicts a catastrophic release of methane in the coming decades due to thawing Arctic permafrost.

In a central Arctic location, a research site in the US state of Alaska, record-breaking level in methane concentration was recorded for this year. The sudden jump sent waves of uneasiness through social networks. 

In August, methane levels above 2040 nmol mol-1 (ppb) were spotted by the Barrow Atmospheric Baseline Observatory, located eight kilometres east of the city of Utqiaġvik (formerly called Barrow) in Alaska. 

To spot methane levels breaking the 2000ppb mark so sharply in this fragile region is unprecedented, as the chart below illustrates.

Dr Paul Balcombe of Imperial College London told E&T that almost half of global methane emissions originate from natural sources. 

There are several sources of methane emissions globally. "Whilst we have a quite accurate understanding of total global emissions, allocating this to specific sources is a bit more uncertain. Emissions come from both natural sources, such as wetlands and man-made - for example agriculture and oil and gas". 

The problem is to accurately pinpoint the sources of methane. "It is easy to know how much methane is in the atmosphere, but it is very difficult to work out what the source is," he said. 

Balcombe adds that there is no consensus on the specific cause of this increase in concentration. Some point the finger at natural gas production, shale gas in particular, whilst others have suggested it comes from biogenic sources. It is also possible that the atmosphere's ability to scrub methane from the air - via chemical reactions - is reducing and could be contributing to the increase.  

Increasing levels of methane in the Arctic region concern experts because it is one of the most potent greenhouse gases in Earth's atmosphere. 

Balcombe says he has witnessed a pretty consistent trend over the last ten years showing increased methane concentrations in the air. "This increase is very bad news for climate change as methane is such a strong climate forcer. Methane emissions are only around 3 per cent of those from carbon dioxide, on a kg basis, but are responsible for approximately a quarter of today's anthropogenic warming", he told E&T.

In 2013, a group of economists and polar scientists claimed that methane released by thinning permafrost could cause catastrophic climate change and cost the world $60tn. 

This finding contradicted other scenarios under which a warming Arctic would enable exploitation of new sources of oil and gas, as well as opening up new polar shipping routes that would contribute to an increase regional trade. 

Despite the worrying development spotted for the Borrow site, the latest data points (in red) are still mere preliminary observations and will require further treatment to validate them - notably undergoing rigorous quality assurance (grey dots) - according to the ESRL website. 

Barrow is well known among experts. Due to its unique location and trained staff, its excellent power and communications infrastructure, Barrow Atmospheric Baseline Observatory hosts numerous cooperative research projects from around the world. 

On Twitter, the latest data attracted the attention of numerous self-appointed climate change advocates. The initial Tweet by Randall Gates at the weekend, "a science advocate and communicator", reached nearly 10,000 likes and retweets. 

Global average levels of atmospheric methane abundance have been recorded as constantly increasing since 2007, after nearly 10 years of stability. 

Balcombe added that more research is needed to better understand the methane dynamics and causes. "But what is clear is that we are capable of substantially reducing our man-made emissions of methane from natural gas supply chains. Greater focus is needed on targeting large emissions and halting this atmospheric increase," he said.

Interactive (From 1986 to 2018)

Clarification (18th of September): 

E&T was contacted over concern for using 2019 data for the Barrow Atmospheric Baseline Observatory site. The data would still not be validated and "may be a bit noisy from local pollution, and could be subject to change in an addendum", an expert said.