Look out for our billboards around Glasgow and Edinburgh which raise the alarm on coal mine methane.*
Methane leaks from coal mines are the climate crisis multiplier that few are talking about. The International Energy Agency (IEA) calculated coal mine methane has a bigger impact on climate change than shipping & aviation combined – our new analysis shows the short-term climate impact is even bigger.
Given the urgent timeline for acting on climate, methane’s immediate and drastic impact on climate is raising alarm as COP26 begins. US Special Envoy for Climate John Kerry announced today that 105 countries around the world have signed the Global Methane Pledge, officially launched today. Among top Coal Mine Methane emitters, the EU, US and Indonesia have already signed the pledge, while China, Russia, India and Australia have not.
The net is closing on methane. The question is whether coal mine methane is treated with the seriousness that it deserves. Coal is dirtier than we think – and just like when burning gas, the direct CO2 emissions are only part of the problem. We can’t forget about the methane leaks that go hand-in-hand with coal production.
The IEA estimates that 40.5 million tonnes (MT) of methane leaked from global operational coal mines in 2020. Using a multiplier of 86, as recommended by the IPCC to assess the short-term climate impact of methane, this means coal mines leak methane equivalent to 3,490 million tonnes of CO2 each year. This is much bigger than the multiplier of 30 used by the IEA when they calculated coal mine methane’s impact was already bigger than aviation and shipping combined.
This means coal mine methane’s short-term climate impact – at 3,490 million tonnes CO2e – is greater than the EU-27’s CO2 emissions, which were 2,920 million tonnes in 2019.
We can also show coal mine methane leaks add 23% to the short-term climate impact of burning coal. Above, we calculated coal mine methane leaks had a short-term impact equivalent to 3,490 million tonnes of CO2; by comparison the IEA estimates the CO2 emissions of burning coal in 2019 were 15 billion tonnes. That would mean methane leaks add 23% to the climate impact of coal. Coal phase-out is a crucial priority for climate regardless – but the potential of reducing coal mine methane emissions only makes it more urgent.
Rapidly acting, and then quick to leave the atmosphere, methane is an incredibly powerful greenhouse gas over short periods of time. Historically, in order to compare its impact on climate relative to carbon dioxide (CO2), methane’s global warming potential was calculated using a 100 year time horizon, over which time methane is around 28-36 times as destructive as CO2. However, measured over a 20 year time horizon, methane’s warming impact rises to 84-87 times that of CO2 (this is explained well by the IEA here). Using the short-term climate impact is most appropriate to understand methane’s part in global warming, and we use the 20 year time horizon for the calculations here. This is in line with the calls in the IPCC AR6 for immediate, deep reductions of ‘climate forcers’ such as methane for a chance to keep to 1.5C warming.
Coal methane leaks are in fact similar to those from mining oil and gas. The IEA methane estimates show coal’s methane emissions are 40.5mt, compared to 36.0mt from oil and 41mt from gas.
Methane is embedded in coal seams, and seeps through the mineshafts, leaking into the atmosphere the whole time that coal is mined. But that’s not all: methane leaks before mining begins, as coal mines are intentionally drained of explosive methane to enable mining to safely begin. And methane leaks for decades after mining has stopped as the methane continues to permeate through the disused mine shaft into the atmosphere.
The IEA shows the top seven largest emitters account for 90% of estimated global coal mine methane emissions. China is number one, due to the sheer volume of coal mined, and Russia is second place due to its deeper, more methane-intensive coal mines. European Union is in third place, most of which is from Poland’s operational coal mines.
The IEA’s calculation of how much methane adds to coal’s climate impact is almost certainly an underestimate. The estimate includes only operational mines, overlooking that many leaks occur before and after the actual mining.
Experts have suggested that emissions could in fact be twice the IEA estimates. Kholod et al. in 2020 suggested far higher total coal mine emissions, almost double the IEA’s estimate.
The range of estimates is an unfortunate consequence of the lack of comprehensive monitoring. What measurements are available are often taken from equipment designed for other purposes (i.e. safety), and emissions from surface mines or from pre- and post-mining activities are generally not measured and thus excluded from official reporting. Likewise, pre-draining and post-mining activities are often not measured and not included in official reporting.
In recent years, new satellite data and processing techniques have shown again and again that coal mine methane detected by satellites in the atmosphere far outstrips the amount reported by mining operations. As new satellites are sent into space and processing technology continues to improve, we will likely see mounting evidence that global coal mine methane emissions have been greatly underestimated.
In October 2021, the IEA published a pathway showing how methane emissions from energy, including from coal, can be reduced by three quarters this decade to keep within 1.5 degrees global heating. As one of the contributors to the report, Ember’s thinking on how to tackle the problem is closely in line with the pathway.
There are five key actions needed to rapidly reduce coal mine methane leaks this decade:
At Ember we believe that a lack of data impedes action. The uncertainties around coal mine methane volumes globally are enormous, with the possibility that they tally at double the accepted estimate – the equivalent of 3.2 billion tonnes of CO2. We need more accurate measurement in order to design effective policies to address the issue.
Currently, most work on coal mine methane emissions is based on desktop research estimates rather than real-time and local measurements. Such estimates are based on old emission factors and science and are very unreliable – showing major differences between even neighbouring mines. Surface coal mines had previously been assumed to release very little methane, yet new satellite data shows that in fact even surface mines can be major emitters. What’s more, coal companies appear reluctant to engage as satellite evidence mounts up.
Independent and systematic measurements must be carried out at all active and closed mines globally, with free access to independent researchers and monitors. These measurements can be supported by aerial and satellite monitoring in order to build a consistent global estimate of the scale of the problem.
The most effective way to address coal mine methane emissions is to reduce the use of coal, particularly in power generation. The IEA’s Net Zero by 2050 report shows that coal power generation needs to fall by two thirds this decade – a massive 67% fall from 2020 to 2030 – to keep warming to 1.5 degrees. That would lead to a similar fall in coal mine emissions from operational thermal coal mines. Legislating the end of new coal is also crucial – especially considering that draining seams ahead of mining is a large source of methane emissions.
Not all coal mines are equal. The worst-performing coal emits as much as 100 times more methane than the least-emitting. Retiring the quarter of global mine capacity with the highest intensity of leaks would halve coal mine methane emissions, according to the IEA’s analysis.
Low cost technologies and abatement techniques for coal mine methane mitigation are already widely available. These approaches are especially desirable at coal mines which are unlikely to close soon – for example for coal supplying steel plants, which will be slower to transition away from coal than power plants.
The good news is many of these technologies are cheap. Historic projects done a decade ago cost only several dollars per tonne of CO2e. When assessed on the short-term impact of methane, that’s only a few dollars per tonne. With economies of scale and technological progress, the costs of some projects could go down even further. This makes curbing coal mine methane one of the easiest wins for short-term climate impacts: affordable, and relatively easy to implement now.
Despite this, companies have not so far voluntarily stepped in to introduce abatement measures. Policies will be needed in order to ensure implementation at the scale needed, such as emissions limits and technology mandates.
Mines must be closed properly to prevent methane leaking for years to come. This challenge will become only more urgent as more mines are closed in the transition to clean energy.
Mine flooding is the most effective way to reduce methane emissions from abandoned coal sites. In cases where flooding is not technically feasible, mines can be sealed. Regulations and proper enforcement can ensure these measures are broadly applied even when companies have no profit incentive to manage an abandoned asset. Properly shuttering mines will create jobs in coal regions, bolstering both ecological and social justice.
The IPCC’s latest report singled out methane reductions as our quickest, best chance to limit global warming to within 1.5 degrees. Even as there is growing momentum to address methane emissions from fossil fuels, the focus is largely on oil and gas extraction.
Coal mine methane is often included as an afterthought, if at all. The European Commission wrote a methane strategy which recommended “coal production will decline in the coming years, so it would be extremely difficult to justify any additional expenditures to implement CH4 recovery techniques”. That was published in 1995. Falling coal use will be critical to reducing coal mine methane, but it should not be used as an excuse to pretend there is nothing further to be done.
At Ember we are working to understand how coal mine methane fits into the electricity transition. Past publications on coal mine methane have dug into Poland’s outsized emissions, analysed IEA findings, and considered how it fits into EU policy. Ember coal mine methane experts have also contributed to publications from the IEA and UN, and are currently partnering with Environmental Defence Fund, Clean Air Task Force and other expert organisations to draw attention to methane from fossil fuels as a part of Methane Moment. In a further effort to coordinate expertise, Ember and UNECE host a regular super-geek event discussing coal mine methane, called Methane Mondays, and we are also preparing a series of methane related publications to build on our earlier work.
Will the world now step up to the challenge?
*The coal mine methane billboards have been generously donated to Ember for the duration of COP26.
Coal Pile in Turkiye
© ilkaydede | iStock
Ember is an energy think tank that aims to accelerate the clean energy transition with data and policy. Ember is the trading name of Sandbag Climate Campaign CIC, a Community Interest Company registered in England & Wales #06714443. 'Ember' and 'Sandbag' are trademarks held at the United Kingdom and European Union Intellectual Property Offices. All content is released under a Creative Commons Attribution Licence (CC-BY-4.0). Website powered by 100% renewable electricity.
