As a result, the Australian benchmark for coal is gradually giving way to a lower-quality, secondary benchmark, one that produces 10% less energy and almost twice the ash, the IEEFA said.

Adani’s proposed Carmichael mine, which would purportedly supply India, would produce coal only about 10% better than the average quality of domestic Indian thermal coal in terms of energy content, it said.

“This comparison doesn’t take into consideration the environmental costs of transporting Australian coal to Indian ports,” it said. “And Carmichael coal if compared to Russian, Indonesian or South African export coal is relatively ‘low energy, high ash’.”

For countries truly seeking to limit the harmful effects of coal-fired power generation pollution, tighter emissions limits are key, a truth that is being embraced by nations as disparate as the US and China, according to the IEEFA.

China has required all coal-fired power plants to be retrofitted with emissions reduction technologies over the past four years. The US EPA this year established expanded new rules on coal-plant emissions.

“When you stack Australian benchmark thermal coal up next to coal from Indonesia, the world’s largest exporter of thermal coal… Australian thermal coal is higher in energy content, but its ash content is double Indonesia’s export-coal average,” the IEEFA said.