Who’s driving climate change? New data logs 72k polluters

It’s when scientists try to apportion the blame more precisely that things get complicated

Upstream from Shanghai along the Yangtze River, a sprawling factory complex in eastern China is churning out tens of millions of tons of steel a year — and immense quantities of planet-warming gases.

The plant’s owner has not disclosed how much the site emits. Now, though, researchers say that by peering down from space, they have found that the factory’s emissions are likely higher than those of any other steel plant on Earth. Here’s how they did it.

Their estimates are part of a new global compendium of emissions released on Wednesday by Climate TRACE, a non-profit coalition of environmental groups, technology companies and academic scientists. By using software to scour data from satellites and other sources, Climate TRACE says it can project emissions not just for whole countries and industries, but for individual polluting facilities. It catalogues steel and cement factories, power plants, oil and gas fields, cargo ships, cattle feedlots — 72,612 emitters and counting, a hyperlocal atlas of the human activities that are altering the planet’s chemistry.

Also Read | Thinning Greenland ice sheet may mean more sea level rise: Study

Scientists have been measuring atmospheric concentrations of carbon dioxide, methane and other greenhouse gases for decades. They know how much average levels are rising worldwide, and they know that burning of fossil fuels is the main driver. It’s when they try to apportion the blame more precisely — How much are specific industries and companies emitting? In which countries? — that things get complicated.

Governments and organisations don’t have monitoring devices strapped to every smokestack and tailpipe, so they generally project emissions using measures of activity: how much coal is burned, how much steel is produced, how much traffic is on the roads. Such estimates aren’t always precise, however, and it can be tricky to avoid double counting.

Satellites from NASA and its Japanese and Chinese counterparts can measure amounts of greenhouse gases in the column of air beneath them, but clouds and night-time darkness obstruct their observations. And satellite measurements don’t directly indicate where or when the gases were emitted. Gases mix and get blown around by weather. They linger in the sky for years, even centuries.

The United Nations asks countries to report emissions to guide global climate talks, like this ongoing climate summit in Egypt. But tallying it all up is a challenge for many governments, let alone for the companies and cities that are setting their own climate goals.

“The whole future of our ability to address climate change, and to avoid the most dangerous effects, hinges on our ability to have solid data,” said Angel Hsu, an environmental policy expert at the University of North Carolina at Chapel Hill. “We need to be able to measure things so we can manage them.”

Climate TRACE says it can produce emissions estimates that are more up-to-date than existing ones, and that rely less on information reported by governments about their own countries’ emissions. It does this largely by mining satellite imagery and other data to get a more precise measure of individual facilities’ production activity, then estimating their emissions.

With steel plants, for instance, the group uses satellite measurements of the heat from blast furnaces to estimate steel output. (The owner of the steel plant in China, Shagang Group, declined to comment.) For power stations, Climate TRACE uses satellite images of the vapour wafting from their chimneys to predict electricity generation.

The group’s analysis suggests that the oil and gas industry emits far more than countries have previously reported, in part because of underestimated emissions from flaring, or the burning of unwanted methane, and the large gas leaks known as “super-emitter events.” In other sectors, though, Climate TRACE’s estimates broadly align with existing ones,
said one of the group’s researchers, Gavin McCormick.

Also Read | The biodiversity crisis is worsening

Having site-by-site data on emissions clarifies how much global warming could be mitigated just by reducing the carbon footprints of the largest polluters, McCormick said.

Climate TRACE has begun working with six regional governments in Mexico, Brazil, South Africa, Spain and Italy to provide information about local emissions, said one of the group’s funders, former Vice President Al Gore.

More granular data can also help businesses compare suppliers to minimise their climate footprint, said Simon Fischweicher, who is the head of corporations and supply chains for the North America division of CDP, a non-profit that collects information about companies’ environmental impact.

“We know we have a climate crisis; we don’t need emissions accounting to tell us that,” he said. “The emissions accounting tells us where the decisions need to be made, what actions need to be taken.”

Climate TRACE’s other backers include the partners of Generation Investment Management, a firm started by Al Gore; Google’s philanthropic arm; and the charitable foundations of Eric Schmidt, the former chief executive of Google, and his wife, Wendy, and John Doerr, a Silicon Valley venture capitalist, and his wife, Ann. Among Climate TRACE’s collaborators is Minderoo Foundation, which was founded by the Australian iron-ore magnate Andrew Forrest.

McCormick said Climate TRACE had “zero plans” to commercialise.

As befits its tech roots, the group has released its data and methods to the public before submitting them for scientific peer review, a process that can take years. McCormick said he and his collaborators were planning to write an academic study based on their work soon.

Why didn’t they do that before? “Because the world is on fire,” McCormick said. “We’re firm believers in double-checking everything, but not a believer in, ‘wait years before you publish.’”

This approach has made some scientists wary. Jocelyn Turnbull, a scientist at GNS Science, a government research institute in New Zealand, said Climate TRACE still had “a ways to go” in demonstrating the quality of its data, though she described the project as “exciting.” Turnbull helps lead an initiative at the World Meteorological Organisation that helps scientists supply governments with information about emissions.

Philippe Ciais, a researcher at the Laboratory of Climate and Environmental Sciences near Paris, helps lead Carbon Monitor, a project that tracks daily carbon dioxide emissions. He called Climate TRACE’s methods “very promising.” But, he said, “everything which is not peer reviewed, I would be sceptical.”