Australia’s open cut coal mines could be emitting more than twice as much methane as official disclosures suggest, casting doubt on national carbon emissions data and efforts to fight climate change, says Superpower Institute chairman and former competition regulator Rod Sims.

Releasing initial results from the institute’s Open Methane satellite monitoring program, Mr Sims said the first independent monitoring for the powerful greenhouse gas had yielded a larger discrepancy with data based on company numbers than results from international monitoring, which had come in about 60 per cent higher.