Threat of methane: an aerial study identifies “super-emitter” discharges

LOS ANGELES, June 18 (Reuters) – The US waste management industry has become the darling of environmentally conscious investors for its work in recycling waste and recovering landfill gases as an alternative fuel.

The leading companies Waste Management Inc (WM.N) and Republic Services Inc (RSG.N) are included in the Dow Jones Sustainability World index, a benchmark for socially responsible investment. The companies’ top investors include funds controlled by billionaire philanthropist Bill Gates and wealth management icon Larry Fink, founder of BlackRock Inc (BLK.N), both of whom are leading advocates for climate action in the United States. companies.

But the waste industry could do a lot more harm to the planet than investors realize, according to a multi-year aerial survey commissioned by California air quality regulators. The survey found that “super-emitter” landfills accounted for 43% of measured emissions of the powerful greenhouse gas methane, overtaking the fossil fuel and agriculture sectors.

NASA’s Jet Propulsion Laboratory in Pasadena and leak detection company Scientific Aviation have been carrying out the overflights since 2016. They discovered that some landfills operated by major US landfill companies, including Republic Services and Waste Management, were leaking of methane up to six times. U.S. Environmental Protection Agency (EPA) facility-level estimates. (See graphic on landfills of “super-transmitters” in California).

The ten largest methane-emitting landfills pumped gas at average rates 2.27 times federal estimates, which are produced by waste management companies using the EPA methodology.

California research could have broad global implications by showing that the waste management industry is playing a bigger role in accelerating climate change than regulators had realized. The investigations could also reveal flaws in the United Nations guidelines for estimating methane emissions that are followed by major governments, including the United States, according to scientists involved in the investigations and regulators interviewed by Reuters.

The research could also bring scrutiny to the waste management industry from policymakers and green investors – who until now have mainly focused on reducing greenhouse gas emissions from waste. fossil fuels, said Eliot Caroom, a researcher at TruValue Labs, which provides investors with environmental and social governance data and analysis.

“One of the most emitting industries, waste management, deserves more attention,” he said.

Gates – who published a book earlier this year called How to Avoid a Climate Disaster – owns more than a third of Republic Services. He owns about 8% of Waste Management through stakes held by the Bill & Melinda Gates Foundation Trust and its personal investment vehicle Cascade Investment LLC, according to fund information. BlackRock owns 4.6% stake in Republic Services and 5% in Waste Management, primarily through funds that track third party indices.

Officials representing Gates and BlackRock have not commented on this story.

Inclusion in the Dow Jones Sustainability Indices is based on S&P Global scores for a number of environmental, social and governance criteria. Waste Management has the highest environmental score in the broader business services sector and an almost perfect score for climate change strategy. Republic Services also received high marks for its climate strategy.

Officials from Republic Services and Waste Management said they were cooperating with investigations over California.

Waste Management said it is stepping up efforts to reduce methane leaks, including improving monitoring, adding more soil to cover landfills and capturing the gas for reuse.

Republic Services said in a statement that the aerial survey data represents snapshot data that may not accurately capture routine emissions from its facility. It has qualified as a leader in the responsible management of landfills.


Methane traps much more heat in the atmosphere than carbon dioxide, although for a shorter period. In total, a tonne of methane causes about 25 times more climate damage over a 100-year period than a tonne of carbon dioxide, according to the EPA.

Concentrations of methane in the atmosphere have increased rapidly in recent years, alarming global governments seeking to limit global warming under the 2015 Paris Agreement on climate change. Measuring these concentrations in the atmosphere is relatively easy, but tracking the sources of emissions is difficult. This difficulty has become a major stumbling block for global policymakers hoping to stem the problem.

The United Nations International Panel on Climate Change (IPCC) issued guidelines for governments in 2006 on how to estimate methane emissions from landfills without direct measurements such as surveys. aerial. Instead, the UN said, methane in landfills can be estimated using factors such as the amount and content of waste stored at the site and the assumed rates of waste decomposition. Such methods “really don’t do the trick anymore,” said Jean Bogner, a researcher at the University of Illinois who has studied methane emissions in landfills since the 1970s.

The IPCC has said it will revise its guidelines if requested by UN member countries.

The UN estimates that landfills and sewage produce around one-fifth of the world’s human-made methane emissions, behind agriculture and the oil and gas industry.

Landfills produce methane when organic materials such as food and vegetation are buried in them, rotting under low oxygen conditions. The gas can escape if the soil covering the landfill is too thin, for example, or if the pipes intended to capture the methane are broken.

In the United States, about a fifth of waste is food, according to the EPA, one of the main contributors to the problem. Methane emissions from landfills are less of a problem in many developing countries, which tend to waste less food and use surface dumps rather than covering waste with earth, according to the IPCC.


On February 26, a plane flown by Scientific Aviation buzzed about 1,500 feet above the Republic Services Forward Landfill at Manteca in the Central Valley and took a series of photos using an infrared spectrometer.

Scientists said the image showed the landfill was emitting more than a quarter of a ton of methane into the atmosphere every hour, the climatic equivalent of nearly 12,000 idling cars on nearby highways. This rate is about six times higher than what the EPA estimated for the facility.

Previous flyovers of the facility since 2017 had shown similar readings.

The California Air Resources Board (CARB), which commissioned the investigation, hopes efforts to find the leaks will ultimately help reduce emissions. A month after the February flyby, state inspectors accompanied officials from the San Joaquin Valley Unified Air Pollution Control District on a trip to examine the Forward dump. The group discovered methane leaks exceeding allowable limits in various locations, issuing two notices of violation to the landfill operator, according to an inspection report seen by Reuters.

In the latest round of overflights that began last fall, regulators have asked landfill operators to use information given to them in real time by aerial surveyors to find and repair leaks on the ground. The state plans to release a report on the effort later this year.

Most leaks are easily fixed by adding more soil or fixing broken pipes meant to capture methane for use as fuel, said Jorn Herner, head of research planning, administration and planning. mitigation of CARB emissions.

The Biden administration announced last month that it would require more U.S. landfills to install gas capture systems to help limit methane emissions. A White House official did not comment on this story.

The state hopes to eventually replace planes with space satellites. California announced in April a $ 100 million project, backed by billionaire Michael Bloomberg, to launch satellites in 2023 that will identify significant greenhouse gas emissions from landfills and other sources, such as refineries, pipelines and farms.

Reporting by Nichola Groom; edited by Richard Valdmanis and Brian Thevenot

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