This is a response to Alexander Zahar’s article in the previous issue of  Climate Law . Zahar argued that ‘the principle of prevention is neither applicable nor of relevance to the problem of climate change.’ 1  Firstly, I discuss Zahar’s scepticism toward state responsibility in the context of climate change. Secondly, I engage critically with Zahar’s claim that the preventive principle only applies to the type of environmental damage that occurs in a short timeframe and in a confined space. I show that some sources of international law do recognize the applicability of the preventive principle to damage to the global environment. Lastly, I dissent with Zahar’s qualification of the climate regime as a derogation to the principle of prevention. I argue that the principle of prevention is a necessary corollary of the rights of states to territorial integrity, although the modalities of application of the principle need to be refined.