The world's biggest coal users are boosting mining in 2017, in an abrupt departure from last year's record global decline and a setback to efforts to rein in climate change emissions.

Data reviewed by The Associated Press show production for China, India and the US is up about six per cent through May compared to the same period last year.

Coal's fortunes had appeared to hit a new low less than two weeks ago with reports that production fell 6.5 per cent worldwide in 2016.

Whether its comeback proves lasting has significant implications for long-term climate emission reduction targets. Coal accounts for almost half of greenhouse gas emissions from burning fossil fuels.

Analysts say the US mining rebound appears temporary but that India's growth should continue. Projections for China are mixed.