As the first commitment period of the Kyoto Protocol comes to a close in 2012, the world faces another decision point at the United Nations Framework Convention on Climate Change meeting in Copenhagen in December. It is clear that total world emissions of greenhouse gases need to decrease sometime during the coming decade, and fall sharply thereafter, if we are to avoid disastrous and irreversible climate change. While industrialised countries generally emit much more per capita than developing countries, some of the latter have per capita emissions approaching the world average. This paper proposes that these advanced developing countries take on commitments to limit future emissions increase to improvements in the gross domestic product or, better yet, the Human Development Index, noting that some countries have achieved much more emission-efficient development than others. Recognising differences in the accuracy of greenhouse gas emissions accounting, we propose separate treatment for energy-related co2 emissions, forestry, agriculture, and fluorinated gases.