The Kyoto Protocol to the United National Framework Convention on Climate Change was formed in 1997 with the aim to stabilise and lower global greenhouse gas emissions. Although the impetus behind the Protocol lay in our scientific understanding of the risks of climate change, the objectives and mechanisms within the agreement were the result of a heated political process that continues to this day. For Kyoto and other agreements to be effective there must be an understanding of why countries participate and their perceived costs and benefits for doing so. Despite growing public awareness of environmental problems, state action still lags behind. International cooperation is vital and it is therefore important that we understand how international agreements can win the support of world governments; and also why they sometimes do not. Here we investigate why the Canadian Government ultimately chose to support and ratify the Kyoto Protocol. The international and domestic climate that shaped the decision of the Prime Minister and Federal Government, and led to ratification on 17 December 2002.