China’s Methane Emissions Rise Despite Tougher Laws, Satellite Data Shows
By Daisy Dunne
Methane emissions from coal mining in China have risen despite stricter government regulations that aimed to curb the greenhouse gas, satellite data shows.
The data, which is published in Nature Communications, finds China's methane emissions rose by 1.1m tonnes a year between 2010 and 2015. This could account for up to a quarter of the rise in methane emissions seen globally over that period, the study finds.
China is the world's largest emitter of methane—a greenhouse gas that is 34 times more potent than CO2 over a 100-year period.
The findings show how satellites can be used to pinpoint greenhouse gas emissions "from misbehaving industries that nobody may have suspected," the lead author told Carbon Brief.
Methane is the second largest contributor to human-caused global warming after CO2.
Globally, the largest driver of human-caused methane emissions is agriculture—particularly livestock and rice production. The second main driver is fossil fuel production, which allows underground methane to "escape" into the atmosphere during the drilling, extraction and transportation process.
China is the world's largest producer and consumer of coal. When coal is mined, methane can escape from the "coal seam"—the name given to a layer of coal in the earth that is thick enough to be exploited, said study lead author Prof. Scot Miller, a researcher of greenhouse gases and air pollution from John Hopkins University in Baltimore. He told Carbon Brief:
"Coal forms underground over long geological time scales and methane is often produced in the coal seams during this process. The methane remains trapped in the coal seam, but it can be released into the atmosphere if the coal seam is mined."
However, there are ways to reduce the methane emissions from the mining process, he added:
"One option is to burn or 'flare' the methane. This process converts methane to CO2, a greenhouse gas that is much less potent per molecule. Another option is to capture this gas and use it to generate electricity or heat homes."
(Methane flaring has faced criticism for being "wasteful". In the U.S., Obama-era environmental regulations sought to minimize the practice—though the new rules were later rolled back by the Trump administration.)
China's government has laid out "ambitious plans" to pursue these options, Miller said. In its 12th five-year plan, which set out policies for 2011-15, the Chinese government aimed to recover and utilize 5.6m tonnes of methane from coal mining. By 2020, it aims to recover 13.2m tonnes of methane.
But the satellite data collected by the research team suggests that these regulations have been "unsuccessful" in curbing methane emissions from mining, Miller said:
"We found that China's methane emissions have been increasing 'business as usual'—and these increases are likely driven by increasing emissions from coal mines. In other words, China's methane regulations have not had a detectable impact on the country's methane emissions."
To study methane emissions from China and other parts of East Asia, the research team used data from the Greenhouse Gases Observing Satellite (GOSAT). The satellite was launched in 2009 by the Japan Aerospace Exploration Agency. (In 2016, Carbon Brief published an interactive showing how satellites, including GOSAT, are used to monitor climate change.)
The satellite detects levels of methane in the atmosphere using infrared sensors. This information is then analyzed by statistical models to link it to changes in methane observed at the Earth's surface, Miller said.
The results show that China's methane emissions rose at a rate of 1.1m tonnes a year between 2010 and 2015. This is indicated on the chart below, which shows the results from this study (green) alongside other previous estimates.
Above chart: Methane emissions from China, according to this study (green; anthropogenic emissions in dashed green), Bergamaschi et al. (2013) (dark blue), Thompson et al. (2015) (light blue), Peng et al. (2016) (triangles), the Emissions Database for Global Atmospheric Research (EDGAR) (black), the U.S. Environmental Protection Agency (EPA) and official statistics reported to the United Nations Framework Convention on Climate Change (UNFCCC) (stars). Note: the y-axis does not begin at zero. Source: Miller et al. (2019)
Since 2007, global methane emissions have been increasing at an annual rate of between 5m and 8m tonnes a year, the study says. This means the increase seen in China could represent between 11 percent and 24 percent of the global rise in methane emissions.
The researchers compared their results to previous studies looking at China's methane emissions from 2000-10 (shown on the chart above). This comparison shows that "China's emissions have been increasing at the same rate as during earlier years, in spite of the government's coal mining regulations", Miller says.
One estimate—from the Emissions Database for Global Atmospheric Research (EDGAR; black line on chart)—found China's methane emissions to be even higher from 2010 to 2012.
This estimate uses a "bottom-up" approach—which involves recording methane emissions from the ground, said Prof. Greet Janssens-Maenhout, a project leader of EDGAR at the European Commission's Joint Research Centre. She told Carbon Brief:
"I think this is a nice [study] and, in fact, the bottom-up estimates and top-down estimates [from this study] don't differ that much. There is much more agreement now than there was in the past."
Also notable is that the estimates for China's methane emissions in 2012 from both this "bottom-up" approach and the new study are higher than the figure reported by China to the United Nations Framework Convention on Climate Change (UNFCCC).
(China is a "non-Annex I" country and so not required to report its greenhouse gas emissions to the UNFCCC on an annual basis.)
Detecting Cow Fields
The modeling technique also allowed researchers to decide whether methane detected by the satellite had originated from a coal mine, a rice paddy, a cow field or a natural source, such as a wetland, Miller said.
The chart below shows a breakdown of methane emissions in China by sector. The sectors considered include coal (orange), rice (purple), agriculture (turquoise), waste (red), oil and gas (green) and natural sources (grey).
Methane emissions (in millions of tonnes) in China between 2011 and 2015 from coal (orange), rice (purple), agriculture (turquoise), waste (red), oil and gas (green) and natural sources (grey). Miller et al. (2019)
The results suggest that coal mining was the main driver of the rise in methane emissions in China from 2011-15, Miller said:
"We saw the largest increases in methane emissions from regions with a lot of coal production and from regions where the coal seams are known to have large amounts of trapped gas.
"Methane is also emitted by agriculture – by cows, manure management and rice paddies. But between 2010 and 2015, coal mining in China increased enormously while rice production and the number of cows did not. These two lines of evidence indicate that coal mining has probably been driving recent increases in methane emissions from China."
The findings suggest that China's "ambitious benchmarks, regulations and incentives" for slashing methane emissions from coal mining had little effect from 2010-15, the authors say.
This could be down to "insufficient infrastructure," "inadequate technology" and "inadequate or poorly-designed policies," the authors write in their research paper.
For example, "most coal mines are located in remote mountainous areas, areas that are poorly connected to cities or natural gas infrastructure"—which is needed to recover methane from coal mines, the authors say.
In addition, some policies to promote methane utilization may have "backfired", the authors noted: "Government policy requires that all mines utilize drained gas with greater than 30 percent methane content…[There is] anecdotal evidence that mine operators may be diluting drained gas to circumvent the requirement."
The new findings highlight how using satellites can give an unbiased picture of how greenhouse gas emissions are changing from country to country, Miller said:
"Countries like the US and China estimate their emissions by tallying the number of coal mines, the number of cows, or the number of natural gas wells. However, these inventories can overlook sources or underestimate emissions from misbehaving actors.
"By contrast, greenhouse gas measurements in the atmosphere can detect emissions across an entire landscape, including emissions that government inventories overlook and emissions from misbehaving industries that nobody may have suspected."
The evidence presented in the study is "alarming" said Dr. Michelle Cain, a science and policy research associate at the Oxford Martin School at the University of Oxford, who was not involved in the research. She told Carbon Brief:
"This is useful [for] piecing together the full story of what is driving global atmospheric methane upwards. Increasing levels of methane in the atmosphere mean additional warming, so this is an important question to answer if we want to work out whether we are on track to limit warming to 1.5 or 2C."
Reposted with permission from our media associate Carbon Brief.
EcoWatch Daily Newsletter
In Major Win for Indigenous Rights, Supreme Court Rules Much of Eastern Oklahoma Is Still a Reservation
Much of Eastern Oklahoma, including most of Tulsa, remains an Indian reservation, the Supreme Court ruled on Thursday.
- Federal Judge Orders Trump Admin to Give Native Americans Their ... ›
- Police Were Ready to Shoot Indigenous Pipeline Protesters in ... ›
- Climate Justice, Indigenous Rights Advocates Rally for Wet'suwet'en ... ›
By Tiffany Means
Summer and fall are great seasons to enjoy the outdoors. But if you're already spending extra time outside because of the COVID-19 pandemic, you may be out of ideas on how to make fresh-air activities feel special. Here are a few suggestions to keep both adults and children entertained and educated in the months ahead, many of which can be done from the comfort of one's home or backyard.
The coronavirus may linger in the air in crowded indoor spaces, spreading from one person to the next, the World Health Organization acknowledged on Thursday, as The New York Times reported. The announcement came just days after 239 scientists wrote a letter urging the WHO to consider that the novel coronavirus is lingering in indoor spaces and infecting people, as EcoWatch reported.
- Airborne Coronavirus Transmission Must Be Taken Seriously, 239 ... ›
- Trump Halts WHO Funding Amidst Criticism of His Own Coronavirus ... ›
- Here's Why COVID-19 Can Spread So Easily at Gyms and Fitness ... ›
- Is the New Coronavirus Airborne? A Study From China Finds Evidence ›
By Angela Nicoletti
The eastern slopes of the Andes Mountains in central Perú are among the most remote places in the world.
- Global Frog Pandemic May Become Even Deadlier as Strains ... ›
- New Species of Diamond Frog Discovered in Remote Pocket of ... ›
- Frogs Are on the Verge of Mass Extinction, Scientists Say - EcoWatch ›
A new analysis by scientists at the Swiss-based International Union for Conservation of Nature (IUCN) found that lemurs and the North Atlantic right whale are on the brink of extinction.
- Trump Admin Denies Endangered Species Protections to Pacific ... ›
- Trump Admin Failed to Protect 241 Species From Extinction ... ›
- New Border Wall Construction Threatens 8 Species With Extinction ... ›
By Julia Vergin
It is undisputed that vitamin D plays a role everywhere in the body and performs important functions. A severe vitamin D deficiency, which can occur at a level of 12 nanograms per milliliter of blood or less, leads to severe and painful bone deformations known as rickets in infants and young children and osteomalacia in adults. Unfortunately, this is where the scientific consensus ends.
Where Does the Deficiency Begin?<p>Nobody knows exactly how much vitamin D a person actually needs. The question of when a deficiency starts is correspondingly controversial. However, vitamin D is becoming increasingly popular.Not only is the pseudo-scientific literature on the "sun vitamin" experiencing an upswing, but the number of published studies has also increased enormously in recent years. For example, in 2019 <a href="https://academic.oup.com/edrv/article/40/4/1109/5126915" target="_blank">a study found that</a> Vitamin D is responsible for keeping the skeleton functional and is associated with cardiovascular diseases, type 2 diabetes and various types of cancer. <br></p>
An All-Rounder<p>Vitamin D levels in the body rise and fall according to sun exposure. If sufficient UV rays reach the skin, the body is able to produce the vitamin itself. However, the human body only derives an estimated 10 to 20 percent of its daily requirement from food.</p><p>The vitamin D that we synthesize from sunlight or food is not biologically active at first. Before the kidneys can produce the biologically active form of the vitamin, known as calcitriol, and release it into the blood, some metabolic processes must take place beforehand.</p><p>In addition, many organs have receptors to which the precursor of calcitriol binds. Further, this substance is also present in blood.</p><p>From this precursor, the organs then produce calcitriol themselves, which the body then uses for countless other processes in the body. This form of vitamin D thus regulates insulin secretion, inhibits tumor growth, and promotes the formation of red blood cells as well as the survival and activity of macrophages, which are important for the <a href="https://www.mdpi.com/2072-6643/5/7/2502/htm" target="_blank">immune system.</a></p>
Low Vitamin D, Severe COVID-19 Disease?<p>A research study carried out <a href="https://www.sciencedirect.com/science/article/pii/S2352364620300067?via%3Dihub" target="_blank">at the University of Hohenheim</a> has now established a link between vitamin D deficiency, certain previous diseases, and severe cases of COVID-19.</p><p>According to the study, "there is a lot of evidence that several non-communicable diseases (high blood pressure, diabetes, cardiovascular diseases, metabolic syndrome) are associated with low vitamin D plasma levels. These comorbidities, together with the often accompanying vitamin D deficiency, increase the risk of severe COVID-19 events."</p><p>"This statement is completely correct," said Martin Fassnacht, head of endocrinology at the University Hospital of Würzburg. However, he qualifies that it is a pure association, "i.e. a mere observation that these events occur together.</p><p>Dr. Fassnacht is very critical of the hype surrounding vitamin D, but not because he denies the vitamin serves important functions. However, studies on humans have not been able to show that vitamin D has the healing powers many often propagate.</p><p>Fassnacht says, "If you take a closer look, the hopes that the administration of vitamin D has a healing effect have not been confirmed so far."</p>
Association Versus Intervention Studies<p>Many studies on the vitamin are association or observational studies. "By definition, these studies cannot prove the causal relationship, but only point to mere correlations," said Fassnacht. The physician tries to illustrate this with an example:</p><p>"Imagine two groups of 80-year-olds. One group is spry, active and does sports. If you compare them with another group living in nursing homes, the difference in vitamin D levels will be dramatic. Life expectancy would also be extremely different."</p><p>But to try to explain the difference in fitness by vitamin D status alone is far too simplistic. "Vitamin D levels are a good measure of how sick someone is. But not more," says Fassnacht. </p><p>According to Fassnacht, none of the intervention studies carried out to date -- that specifically examined the effect of vitamin D on various diseases -- has been able to confirm the previous association and laboratory studies or the presumed positive effect of vitamin D.</p>
Further Research Is Needed<p>"If a coronavirus infection is suspected, it is therefore absolutely necessary to check the vitamin D status and quickly correct any possible deficit," said the recommendation of the paper published by the University of Hohenheim.</p><p>"Studies are underway to see whether vitamin D helps in COVID-19 infection, but I personally do not believe that this is really the case," says endocrinologist Fassnacht. Nevertheless, he says it is of course useful to carry out these studies.<br></p><p>"I don't want to rule out that there are actually subgroups of people who benefit from an additional vitamin D dose," he says. After all, this has been proven to be the case with a severe deficit.</p><p>In view of the study situation, Fassnacht does not think much of preventive, nationwide vitamin D substitutes. "My belief that the vitamin helps somewhere is very low. But, of course, I can be wrong."</p>
- 8 Ways to Tell if You Are Vitamin D Deficient - EcoWatch ›
- 7 Healthy Foods That Are High in Vitamin D - EcoWatch ›
- 7 Nutrient Deficiencies That Are Incredibly Common ›
Ocean scientists have been busy creating a global network to understand and measure changes in ocean life. The system will aggregate data from the oceans, climate and human activity to better inform sustainable marine management practices.
EcoWatch sat down with some of the scientists spearheading the collaboration to learn more.
Climate models are predicting faster warming of the North Atlantic Ocean, which will shift the Gulf Stream. NASA
- Could the Climate Crisis Spell the End for Maine Lobster? - EcoWatch ›
- 5 Reasons Why Biodiversity Matters - EcoWatch ›
- World Leaders, Media Ignore Biodiversity Report Detailing Mass ... ›
- The Top 10 Ocean Biodiversity Hotspots to Protect - EcoWatch ›