Abstract/Summary

An obligation of conduct is an obligation to make an honest endeavour, notwithstanding the outcome. From the no-harm principle to the United Nations Framework Convention on Climate Change and the Paris Agreement, obligations of conduct play a central role in the international law on climate change mitigation. They are not simply the result of political tradeoffs with reluctant States, but they address real concerns with the unpredictable costs of implementing specific mitigation targets over a decade or more. This article retraces the origins of obligations of conduct in the French law of obligations and its reception in international law. It then highlights the prominence of such obligations in the international law on climate change mitigation. Based on this analysis, it contends that obligations of conduct are an effective tool to promote ambition and participation to international efforts on climate change mitigation.