Connect with us

Published

on

Methane, a potent greenhouse gas, is responsible for about 30% of the global temperature increase observed since the industrial revolution.

China accounts for more than 10% of annual global human methane emissions, in large part due to unintended releases – known as “fugitive” emissions – from its energy sector.

In a recently published study, we take a closer look at China’s coal-mine methane (CMM) emissions, which account for roughly 40% of the nation’s total methane emissions.

Leveraging newly collected, mine-specific data, we develop granular estimates of CMM emissions in China since 2000.

These estimates reveal that China’s coal production is shifting towards provinces with lower-emission mines.

In addition, there has been a significant increase in the capturing of methane from coal mines for energy use.

Together, these developments have helped to limit the rise of CMM emissions, despite an overall increase in coal production since 2016.

Mine data

To estimate CMM emissions at a granular level, we needed to understand how emissions vary from one mine to the next across China.

To do this, we made use of existing safety regulations in China. As methane is a highly flammable gas, the Chinese government enforces mandatory methane gas level identification in coal mines and implements safety regulations accordingly.

Coal mines are categorised based on their “methane emission factors”, the volume of methane emitted per tonne of coal produced.

At one end are low-gas mines, with an emissions factor of less than 10 cubic metres (m3) of methane emitted per tonne of coal. At the other are high-gas mines, at more than 10m3 of methane emitted per tonne. Beyond this are “outburst” mines, which are those that have experienced coal seam or gas outburst incidents.

To get a clearer sense of how much low-gas, high-gas and outburst mines emit in practice, we built a model of the relationship between gas levels and emission factors, using a 2011 database of all Chinese coal mines.

This database includes information on methane gas levels, mine-specific emission factors, coalbed depth, mine ownership and production capacity. We further validated this relationship with newly collected coal mine data from 2023, published by Chinese local governments.

The results show that the distribution of emission factors, as shown in the figure below, varies significantly with gas level.

The top row in the figure below shows the emissions factors for a range of mines in 2011 classed as low-gas (top left, green), high-gas (top centre, pink) or outburst (top right, red). The dashed vertical lines show the central estimate for each type, ranging from 4.1m3 per tonne for low-gas mines through to 19.9m3/tonne for high-gas and 28.4m3/tonne for outburst mines.

The bottom row shows the same metrics based on the more recent 2023 data.

The distribution of methane emission factors for low-gas (green), high-gas (pink) and outburst coal mines in China.
The distribution of methane emission factors for low-gas (green), high-gas (pink) and outburst coal mines in China. Top row: 2011 data. Bottom row: 2023 data. Dashed vertical lines show the central estimate of emission factors in each category. Credit: Zhang et al. (2026)

The strong correlation shown in the data above suggests that gas level is a crucial indicator of how much methane a coal mine emits.

In contrast, our analysis reveals no significant correlation between how much a coal mine emits and either coal mine depth or ownership.

Comparing the distributions for the same gas levels between 2011 and 2023 also shows that the link between gas levels and methane emissions remains fairly constant over time.

Therefore, the gas level of a mine can reliably serve as a proxy for its methane emissions per tonne of production, when direct measurements are unavailable.

Provincial shift

To estimate CMM emissions for each province in China, we assumed that the percentage of coal produced by mines of each gas level remains roughly constant as in 2011.

For instance, if 20% of Guizhou’s coal production in 2011 came from low-gas mines, we maintained this percentage for subsequent years.

We then calculated CMM emissions by multiplying provincial-level production-weighted emission factors by total coal production.

The line chart below illustrates our estimated CMM emissions since 2000.

The raw estimates, depicted by the lower grey dashed line, show a rapid increase in CMM emissions from approximately 5m tonnes in 2000 to nearly 21m tonnes in 2013.

This was followed by a decrease to 15m tonnes in 2016 and a subsequent rebound to 24m tonnes in 2023.

The decline between 2013 and 2016 aligns with a period of reduced coal production in China.

Estimated coal mine methane emissions in China from 2000 to 2023
Estimated coal mine methane emissions in China from 2000 to 2023, including raw estimates (lower grey bound), raw estimates with abandoned mine methane (upper grey bound), and estimates when methane capture and use is considered (blue). Source: Zhang et al. (2026)

On the chart, the upper grey line represents CMM emissions when abandoned coal mines are included.

These mines, which continue to release methane long after operations cease, were responsible for 4.8m tonnes of methane emissions in 2020, contributing approximately 25% to the total CMM emissions.

Meanwhile, the blue line shows CMM emissions when the capture and use of methane in energy supply is taken into consideration.

National methane utilisation increased from 1.2m tonnes in 2008 to 3.7m tonnes in 2020, resulting in a reduction of total emissions by 5% and 17%, respectively.

It is noteworthy that CMM emissions did not immediately rebound after 2016, despite a reported increase in coal production by China’s National Bureau of Statistics.

This delay can likely be attributed to shifts in production locations to lower-emissions provinces, the closure of high-emissions mines and the adoption of technologies for capturing and using methane that effectively mitigate emissions.

The figure below compares CMM emissions across provinces in 2012 and 2021, two years with nearly identical total coal production levels.

Overall, changes in methane emissions closely mirrored shifts in where the coal was being mined. There is a clear geographic trend: production and emissions surged in northern and north-western regions such as Xinjiang, Shaanxi and especially Shanxi.

In fact, Shanxi alone emitted nearly 8m tonnes of coal-mine methane in 2021, making up roughly half of China’s total CMM emissions.

Meanwhile, both production and emissions dropped in south-western provinces, including Guizhou, Sichuan and Yunnan.

Changes in provincial coal mine methane emissions in China between 2012 and 2021, million tonnes.
Changes in provincial coal mine methane emissions in China between 2012 and 2021, million tonnes. Source: Zhang et al. (2026)

The figure shows that China’s coal production has switched from regions in the south-west where emissions per unit of coal production are relatively high, to lower-emission areas in the north and north-west. At the same time, total production levels have stayed similar, at just over 4bn tonnes in both 2012 and 2021.

Tackling methane

China has signalled its intention to address methane emissions, with key tasks for the next five years outlined in a national methane action plan published in 2023.

The broad trends of CMM emissions observed in this study will likely continue in China.

Small-scale coal mines – those producing less than 300,000 tonnes of coal per year – are at risk of closing or being consolidated, while increased production from large-scale, lower-emission mines in Xinjiang and Inner Mongolia will likely lead to an overall reduction in national production-weighted emission factors.

(This reduction in the rate of emissions per unit of coal production does not guarantee a reduction in methane emissions overall, as several analyses show this also depends on the total coal output. Even following closures, methane may still leak from abandoned mines.)

However, this regional shift in coal production – and, thus, methane emissions – could also help to address public health concerns from pollution associated with the gas.

The Chinese government has also introduced significant changes in policy on the capturing and use of methane gas. The Ministry of Ecology and Environment recently revised coal-mine methane standardsto mandate the capture and use of methane with concentrations above 8%, down from a previous 30%.

In addition, the government has a programme providing financial incentives for capturing methane and reducing CMM emissions.

Together, these measures could help China achieve its short- and medium-run methane capture and use goals set by the methane action plan.

The post Guest post: How changes to coal mining have affected China’s methane emissions appeared first on Carbon Brief.

Guest post: How changes to coal mining have affected China’s methane emissions

Continue Reading

Climate Change

Corpus Christi Cuts Timeline to Disaster as Abbott Issues Emergency Orders

Published

on

The governor’s office said the city’s two main reservoirs could dry up by May, much sooner than previous timelines. But authorities still offer no plan for curtailment of water use.

City officials in Corpus Christi on Tuesday released modeling that showed emergency cuts to water demand could be required as soon as May as reservoir levels continue to decline.

Corpus Christi Cuts Timeline to Disaster as Abbott Issues Emergency Orders

Continue Reading

Climate Change

Middle East war is another wake-up call for fossil fuel-reliant food systems

Published

on

Lena Luig is the head of the International Agricultural Policy Division at the Heinrich Böll Foundation, a member of the Global Alliance for the Future of Food. Anna Lappé is the Executive Director of the Global Alliance for the Future of Food.

As toxic clouds loom over Tehran and Beirut from the US and Israel’s bombardment of oil depots and civilian infrastructure in the region’s ongoing war, the world is once again witnessing the not-so-subtle connections between conflict, hunger, food insecurity and the vulnerability of global food systems dependent on fossil fuels, dominated by a few powerful countries and corporations.

The conflict in Iran is having a huge impact on the world’s fertilizer supply. The Strait of Hormuz is a critical trade route in the region for nearly half of the global supply of urea, the main synthetic fertilizer derived from natural gas through the conversion of ammonia.

With the Strait impacted by Iran’s blockades, prices of urea have shot up by 35% since the war started, just as planting season starts in many parts of the world, putting millions of farmers and consumers at risk of increasing production costs and food price spikes, resulting in food insecurity, particularly for low-income households. The World Food Programme has projected that an extra 45 million people would be pushed ​into acute hunger because of rises in food, oil and shipping costs, if the war continues until June.

Pesticides and synthetic fertilizer leave system fragile

On the face of it, this looks like a supply chain issue, but at the core of this crisis lies a truth about many of our food systems around the world: the instability and injustice in the very design of systems so reliant on these fossil fuel inputs for our food.

At the Global Alliance, a strategic alliance of philanthropic foundations working to transform food systems, we have been documenting the fossil fuel-food nexus, raising alarm about the fragility of a system propped up by fossil fuels, with 15% of annual fossil fuel use going into food systems, in part because of high-cost, fossil fuel-based inputs like pesticides and synthetic fertilizer. The Heinrich Böll Foundation has also been flagging this threat consistently, most recently in the Pesticide Atlas and Soil Atlas compendia. 

We’ve seen this before: Russia’s invasion of Ukraine in 2022 sparked global disruptions in fertilizer supply and food price volatility. As the conflict worsened, fertilizer prices spiked – as much from input companies capitalizing on the crisis for speculation as from real cost increases from production and transport – triggering a food price crisis around the world.

    Since then, fertilizer industry profit margins have continued to soar. In 2022, the largest nine fertilizer producers increased their profit margins by more than 35% compared to the year before—when fertilizer prices were already high. As Lena Bassermann and Dr. Gideon Tups underscore in the Heinrich Böll Foundation’s Soil Atlas, the global dependencies of nitrogen fertilizer impacted economies around the world, especially state budgets in already indebted and import-dependent economies, as well as farmers across Africa.

    Learning lessons from the war in Ukraine, many countries invested heavily in renewable energy and/or increased domestic oil production as a way to decrease dependency on foreign fossil fuels. But few took the same approach to reimagining domestic food systems and their food sovereignty.

    Agroecology as an alternative

    There is another way. Governments can adopt policy frameworks to encourage reductions in synthetic fertilizer and pesticide use, especially in regions that currently massively overuse nitrogen fertilizer. At the African Union fertilizer and Soil Health Summit in 2024, African leaders at least agreed that organic fertilizers should be subsidized as well, not only mineral fertilizers, but we can go farther in actively promoting agricultural pathways that reduce fossil fuel dependency. 

    In 2024, the Global Alliance organized dozens of philanthropies to call for a tenfold increase in investments to help farmers transition from fossil fuel dependency towards agroecological approaches that prioritize livelihoods, health, climate, and biodiversity.

    In our research, we detail the huge opportunity to repurpose harmful subsidies currently supporting inputs like synthetic fertilizer and pesticides towards locally-sourced bio-inputs and biofertilizer production. We know this works: There are powerful stories of hope and change from those who have made this transition, despite only receiving a fraction of the financing that industrial agriculture receives, with evidence of benefits from stable incomes and livelihoods to better health and climate outcomes.

    New summit in Colombia seeks to revive stalled UN talks on fossil fuel transition

    Inspiring examples abound: G-BIACK in Kenya is training farmers how to produce their own high-quality compost; start-ups like the Evola Company in Cambodia are producing both nutrient-rich organic fertilizer and protein-rich animal feed with black soldier fly farming; Sabon Sake in Ghana is enriching sugarcane bagasse – usually organic waste – with microbial agents and earthworms to turn it into a rich vermicompost.

    These efforts, grounded in ecosystems and tapping nature for soil fertility and to manage pest pressures, are just some of the countless examples around the world, tapping the skill and knowledge of millions of farmers. On a national and global policy level, the Agroecology Coalition, with 480+ members, including governments, civil society organizations, academic institutions, and philanthropic foundations, is supporting a transition toward agroecology, working with natural systems to produce abundant food, boost biodiversity, and foster community well-being.

    Fertilizer industry spins “clean” products

    We must also inoculate ourselves from the fertilizer industry’s public relations spin, which includes promoting the promise that their products can be produced without heavy reliance on fossil fuels. Despite experts debunking the viability of what the industry has dubbed “green hydrogen” or “green or clean ammonia”, the sector still promotes this narrative, arguing that these are produced with resource-intensive renewable energy or Carbon Capture and Storage (CCS), a costly and unreliable technology for reducing emissions.

    As we mourn this conflict’s senseless destruction and death, including hundreds of children, we also recognize that peace cannot mean a return to business-as-usual. We need to upend the systems that allow the richest and most powerful to have dominion over so much.

    This includes fighting for a food system that is based on genuine sovereignty and justice, free from dependency on fossil fuels, one that honors natural systems and puts power into the hands of communities and food producers themselves.

    The post Middle East war is another wake-up call for fossil fuel-reliant food systems appeared first on Climate Home News.

    Middle East war is another wake-up call for fossil fuel-reliant food systems

    Continue Reading

    Climate Change

    Are There Climate Fingerprints in Tornado Activity?

    Published

    on

    Parts of the Southern and Northeastern U.S. faced tornado threats this week. Scientists are trying to parse out the climate links in changing tornado activity.

    It’s been a weird few weeks for weather across the United States.

    Are There Climate Fingerprints in Tornado Activity?

    Continue Reading

    Trending

    Copyright © 2022 BreakingClimateChange.com