The United Nations will track big methane emitters from space and give them a deadline to come clean before the data is released.

The UN Environment Programme (UNEP) said the Methane Alert and Response System — MARS for short — aims to help companies respond to major emissions sources and provide transparent, independent data. 

The system will launch next year.

It uses satellite measurements from NASA and the European, German and Italian space agencies. Data from private satellite operators will also be included in future.

“Each of these instruments gives us a correct answer to a question that is slightly different, because each of them sees different things,” said Manfredi Caltagirone, head of the  International Methane Emissions Observatory at UNEP.

“So the only way you can have a correct picture is to connect them all together.”

The data will be released 45 to 75 days after it is gathered, giving companies time to fix the leaks before they become public.

“We think it is important not to just create a shaming tool, but to engage the operators and governments so they can act on the specific event,” Mr Caltagirone said.

Releasing the measurements on a UN-backed platform would set a standard to prevent companies from “shopping around” for data that makes them look best, he said.

But there will be no way to force any emitters to take action.

“We are realistic that certain companies and certain countries will be more cooperative than others,” he said.

“But we can make sure this information is available to those who are interested in it.”

The first data will be published in the second half of next year, focusing on large methane leaks.

The platform will later include less dramatic but equally significant sources of emissions like livestock and rice farms.

Cutting methane emissions worldwide is key to the Paris climate accord’s ambitious goal to cap global warming at 1.5 degrees Celsius by the end of the century compared to pre-industrial times.

Australia, the United States, European Union and others last year launched a pledge to cut overall methane emissions worldwide by 30 per cent by 2030.