As countries around the world shift toward greater use of non-fossil fuels, the wide range of methods used to set targets for remaining fossil fuel emissions and to measure results and progress is highly disparate and needs to be standardized, authors of this Policy Forum emphasize. Standardization is increasingly important as the 21st Conference of the Parties (COP21) to the United Nations Framework Convention on Climate Change (UNFCCC) begins on 30 November, where world leaders will convene in Paris and once again discuss their countries' long-term energy targets. Three commonly used means by which to determine energy statistics involve using electricity production, efficiency of electricity production, or physical energy content as measurements; however, different methods within these forms of measurements can cause disparities. An example that best highlights these disparities is China -- the world's largest energy producer, energy consumer, and emitter of energy-related carbon dioxide. It uses a distinct fourth method based on coal power plants that is not well-documented in the literature, nor transparent in policy documents. In November 2014, as part of the U.S.-China Joint Announcement on Climate Change, China stated its intention to increase the share of nonfossil fuels in primary energy consumption to around 20% by 2030. Joanna Lewis et al. evaluated China's method-derived values in the context of reaching this goal using methods commonly used internationally. These calculations suggest that the share of nonfossil energy China will use in 2030 will be equivalent to 9%, not 20%. As world leaders prepare to set their new emissions targets, this example highlights the need for a standardized way to measure results more critically, the authors say.