Cows鈥� contribution to climate change is about to face a whole new level of scrutiny. 杏吧原创s 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鈥檚 greenhouse gas emissions.
First detected on 2 February, the methane was traced back to the probable source using modelling based on wind data. 鈥淲e鈥檙e very confident it鈥檚 the cattle,鈥� 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.
Advertisement
鈥淚t鈥檚 the classic story of, once you鈥檙e able to measure it, then you鈥檙e able to assess it and hopefully make improvements,鈥� 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 鈥渕any more observations鈥� 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鈥檚 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.
Sign up to our free Fix the Planet newsletter to get a dose of climate optimism delivered straight to your inbox, every Thursday
