An Environmentalist, an Engineer, in a Heatwave
Two senior figures from opposite traditions agreed on a category of climate intervention. The House of Lords, during Climate Action Week, was not discussing it.
London is under a heat-health warning this week. Temperatures into the thirties, the city moving slower, the climate establishment moving through it for London Climate Action Week. Earlier this month I sat down to record a long conversation with Jonathon Porritt, a foundational figure of the British environmental movement, and Richard Mattus, the Swedish industrial emissions engineer who led the 2025 UNECE Best Practice Guidance on the abatement of methane from coal mines. The two had not met before.
On Monday morning, the House of Lords convened a stakeholder meeting on methane mitigation in the fossil fuel sector. Baroness Sheehan, who chaired the 2024 Lords inquiry on methane, hosted. The Clean Air Task Force, the UK Department for Energy Security and Net Zero, the Global Methane Hub, and the Climate and Clean Air Coalition were among the convenors. The day was about the Fossil Fuel Regulatory Programme: oil, gas, and coal, the printed agenda said.
I conducted that conversation on 10 June. My colleague Kaj Embrén was at the Lords meeting on 22 June. The gap between them is the substance of this article.
The conversation
The category Porritt and Mattus had come together to discuss is coal mine methane abatement: the engineering destruction of the methane that working coal mines release into the atmosphere for safety reasons. The methane is roughly eighty-two times more potent than carbon dioxide over a twenty-year horizon, and it sits in the atmosphere for about twelve years — the shortest of any major greenhouse gas. Abating it now would deliver the most concentrated near-term warming reduction available in the climate ledger.
Mattus, who has spent four decades inside the engineering sector, was direct. “Coal mines must be closed,” he said. “It has started — UK, Germany, Spain, France. But it's taking time. Coking coal, or met coal for steel production — that will stay for several decades.” The methane those mines release through their ventilation shafts is what regenerative thermal oxidisers, the principal abatement technology, are built for. The work is mature. The economics, on the existing carbon-market basis, sit at single-digit dollars per tonne of CO2-equivalent on the GWP-20 framing the science of methane actually deserves.
Porritt, a senior voice of the environmental movement for forty years, agreed with Mattus's technical assessment and made the methodological case. “This is about as close as you can get to a gold standard,” he said of the verification, reporting, and measurement of coal mine methane abatement under the existing protocols. The credits are physical. The measurement happens at the meter. The integrity argument that has wounded other parts of the voluntary carbon market does not cause the same problem here.
And then Porritt named, from inside the movement, what he and Mattus both knew.
“The environmental NGOs don't want to be connected to coal mining, and they're pretty suspicious about credits, about carbon markets in general. So it's a hard ask, let's be honest.” — Jonathon Porritt
By the end of the conversation, what each man was arguing had become clear. Porritt advocates, as he has for decades, for the fastest possible phasing out (not down) of thermal coal. Mattus, from inside the engineering of mine emissions, would close the operating mines as fast as the economics will allow. What both were arguing is that the methane the mines that are operating today, and will be operating for years yet — thermal coal in the major Asian economies, coking coal for steel everywhere — is being released into the atmosphere unabated, while the technology and the economics that would address it have been ready for at least a decade. An environmentalist and an engineer had arrived at the same place from opposite starting points.
The room down the road
During Climate Action Week, in the House of Lords, the Fossil Fuel Regulatory Programme stakeholder meeting convened. The programme, launched by the Climate and Clean Air Coalition and the Clean Air Task Force at COP29 in 2024, supports developing-country governments to build the regulatory capacity to reduce methane from oil, gas, and coal. Egypt, Brazil, and Bosnia and Herzegovina were announced as new joiners. Dr Alan Whitehead CBE, the UK Minister of State for Energy Security and Net Zero, opened with the UAE's Assistant Minister Abdulla Balalaa. The architecture being assembled is real and the people convening it are doing serious work.
Coal was named on the agenda. The substantive conversation was about oil and gas. Across the recorded transcript of the meeting, there is one reference to coal in the context of methane mitigation — a participant from Chile noting that their country had transitioned from coal-fired power to natural gas. There is no discussion of coal mine methane as a category. No discussion of the abatement technology Mattus has spent four decades engineering. No discussion of the financial architecture that would finance its deployment at scale.
The Clean Air Task Force's own published material on the Fossil Fuel Regulatory Programme states that “half of emissions from coal today can be abated with existing technology, often at low cost.” That sentence was not the meeting's subject.
The reasons are the ones Porritt had named earlier. NGOs do not want to be connected to coal. Carbon credits attached to coal-adjacent activity remain difficult to advocate for. The cultural pattern has shaped the agenda. The agenda has shaped the room. The room had everyone in it who could move the question, and the question was not moved.
What the heat is doing
Methane is the climate lever with the steepest urgency curve. Eighty-two times the potency of carbon dioxide. A twelve-year half-life in the atmosphere. The warming the city is experiencing this week is the kind of near-term warming that methane abatement, more than any other single intervention, directly addresses. The category of methane abatement that addresses the largest unaddressed source — coal mine methane, which has been sitting outside the financial and institutional architecture since the UN's Clean Development Mechanism was wound down a decade and a half ago — is the category the chamber did not discuss.
Porritt was clear at the close of our conversation about what he thought was coming. “There's going to be a reckoning,” he said, “when a lot of these forest-based credits are seen not to have delivered the abatement that we were looking for. And then people are going to be looking around for a different understanding of what is meant by a gold standard credit.” The credit category most ready for that search has not been picked up by the institutions that would pick it up.
One conversation, one meeting. Weeks apart. In one, an environmentalist and an engineer agreed. In the other, the architecture being assembled around their question continued without it. The heat is doing the warming. The lever that would slow it is methane abatement. The institutional silence is refusing to fund it.