Transparency is fundamental to environmental governance. It promotes public trust, goodwill, and credibility in environmental decision making. It also ensures that monitoring and enforcement of emissions reduction targets are efficient and effective. As the impacts of climate change increase, it is urgent that scholars and policy makers develop and test criteria for transparency in both the calculation of emissions reductions and the public reporting of emissions. This article highlights basic principles of transparency that should inform such criteria and that may be applied on a transnational basis. We also examine China's recently implemented pilot emissions trading schemes and find that the approach in China does not yet comply with our suggested principles. Nevertheless, the positive direction of environmental governance in this region is encouraging.