When Sara Mikaloff-Fletcher watched a SpaceX rocket take off and smoothly release a box-shaped satellite into orbit earlier this month, it marked the achievement of a long-held dream. The Niwa scientist studies global cycles of greenhouse gases and has been one of the drivers of New Zealand’s first official government-funded space mission.
MethaneSAT is a global initiative led by the US Environmental Defense Fund in partnership with the New Zealand Space Agency to track rising emissions of methane, a potent greenhouse gas that is responsible for about 30% of warming globally.
The mission’s focus is on anthropogenic methane emissions from pipeline leaks and agriculture. “It’s one of those very low-hanging fruit for climate action,” Mikaloff-Fletcher says. “It’s a climate solution where everyone wins.”
The US project works to identify methane leaks from oil and gas production but Mikaloff-Fletcher’s role is to lead the development of agricultural applications. That’s the exciting part, she says, “because it’s not the first satellite that’s been useful for oil and gas [leak] work, but accurate agricultural applications are really new”.
Satellite monitoring has already helped pinpoint agricultural super emitters, such as massive dairy or feedlot farms in the US, but “this is the first time we will be able to monitor the kind of pastoral agriculture we have here in New Zealand at the kind of spatial resolution we need to support regional climate action.”
MethaneSAT fills a resolution gap among the satellites already in orbit. Some are global mapping satellites with low spatial resolution; others are focused on looking at very small areas with high resolution. The former are good for continental-scale studies and the latter are helpful in tracking down specific methane leaks in areas where problems with pipes have already been identified.
“What makes MethaneSAT different is it has a large viewing area, a swathe 200km by 200km, and inside that it scans at high spatial resolution and very high precision. It will be able to detect as few as two parts of methane per billion when averaged over a 1km spatial resolution.”
Now that MethaneSAT is safely in orbit, it will start monitoring a number of priority sites by April then start returning comprehensive global data regularly by June. At that point Mikaloff-Fletcher will conduct research with a suite of methane-monitoring instruments that work on a paddock scale to estimate emissions in a number of ways to “see exactly how well the satellite is able to quantify those emissions”.
The data she expects to receive won’t necessarily be pinpointing individual farms as emissions sources but “we’ll be able to detect and quantify methane emissions over New Zealand’s agricultural areas, get a general picture and spatial mapping”.
The real value of New Zealand’s contribution is that the country is a perfect natural laboratory to test the satellite’s capability. Methane accounts for more than 43% of total greenhouse gas emissions. Most of it comes from belching livestock so “a lot of the value of this work is not just for understanding New Zealand’s emissions but for giving others around the world confidence in how good that data is”.
More than 150 countries, including New Zealand, signed a global methane pledge in 2021 to cut their emissions of the gas by 30% from 2020 levels by 2030.
Partnering on the MethaneSat mission is one of New Zealand’s initiatives towards this goal.
And Mikaloff-Fletcher is optimistic that as well as delivering the data it will help maintain “hope that we can tackle what sometimes feels like an insurmountable problem”.
