Japan is ramping up its carbon credit trading efforts, even as greenhouse gas offsets receive heightened scrutiny following reports that a significant number do not live up to their claims.

Over the past year, the Tokyo Stock Exchange, startups and others have each launched marketplaces for carbon credits.

The credits, which are certified by governments or independent bodies, are tradable instruments that represent a reduction of a certain amount of emissions, allowing polluters to offset their own emissions by buying them.