This paper compares the decision processes in which the governments of China and the United Kingdom or responded，to severe air pollution in their respective capitals，thereby presenting differences between different systems and governance traditions in terms of how they perform in handling similar environmental crises.This paper pays extra attention to how different governments reach a consensus on relevant issues and decisions within the administrative system and at the level of society.The Chinese government shows a relatively closed model of political mobilization in making decisions concerning the air pollution crisis in Beijin.There are insufficient discussions throughout this process whether within the government or across society despite that the Chinese government is able to respond rapidly to public concerns and issue relevant policies in a very efficient manner.Moreover，the room for autonomous social mobilization and participation，which were once active，shrinks rapidly since the government played a leading role in dealing with the haze.Since tackling air pollution，in itself，comes with high technological complexity and uncertainties，such a seemingly efficient decision model，with a lack of sufficient discussions and social participation，will most likely bring risks to the implementation stage.The process in which the UK government made decisions concerning the air pollution crisis in London seemed slow，but the UK government paid more attention to reaching a consensus within the legislative and administrative systems and at the level of society，such that more time and room could be left for technical discussions，interest negotiations and autonomous social mobilization.From a long-term perspective，therefore，this was detrimental to reducing the political cost of policy implementation.