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Methane emissions from cows spotted from space for the first time

A satellite has been used to identify a California farm as the source of methane plumes, marking a new level of precision for independent monitoring of agriculture’s greenhouse gas emissions
Methane emissions from cows detected by satellite
GHGSat

Cows’ contribution to climate change is about to face a whole new level of scrutiny. èƵs have previously monitored the methane emissions of cattle from the ground and planes and now they have seen cow-related methane plumes from space for the first time.

Canadian aerospace firm GHGSat used one of its three satellites to pinpoint the source of five methane plumes as a single cattle farm in the San Joaquin Valley nearly 10 kilometres south-east of Bakersfield in California. The exercise marks a new level of precision for independent monitoring of agriculture’s greenhouse gas emissions.

First detected on 2 February, the methane was traced back to the probable source using modelling based on wind data. “We’re very confident it’s the cattle,” says Brody Wight at GHGSat. The plumes spotted were modest, and would total around 5000 tonnes of methane if emissions were consistent over a year. Identifying such a small amount is made possible by the higher resolution of recent satellites, says Wight.

“It’s the classic story of, once you’re able to measure it, then you’re able to assess it and hopefully make improvements,” he says. The approach could be useful in verifying emissions for farmers trialling ways to lower cattle emissions, for example. Ideas include , and using cows bred to be more climate friendly.

Using satellites to monitor methane would enable independent spot checks, says Wight. Monitoring from space could also be used to verify if countries with livestock-intensive industries, such as New Zealand, are delivering on methane cuts promised under the Paris Agreement.

Satellites have already been used in initiatives to curb methane emissions from the fossil fuel industry, such as detecting leaks in gas pipelines. But Brody says the California cattle are just the first of “many more observations” of methane from agriculture planned.

at Royal Holloway, University of London, says the California case is probably the first direct observation from space of a cattle farm’s emissions. The approach is useful where the location of emissions is already known, and could help routine monitoring by regulatory agencies, he says. But for more dispersed agricultural sources, and in the tropics where cloud cover can be thick and long-lasting, Nisbet says monitoring from the ground and with drones might work better.

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Topics: methane / Satellites