The nature of climate change is such that no one state can solve the problem by itself, nor is any one state likely to incur the costs of emission mitigation without some assurance of comparable action by others (Olson 1965; Hardin 1968). This same dynamic is replicated in federal states: How can one attain joint objectives and coordinated actions from autonomous yet interdependent jurisdictions in the face of considerable incentives to defect? As of 2013, Canada has been unable to reach agreement on national objectives, policy mechanisms, or the allocation of costs between sources and Canadian provinces and has relied instead on uncoordinated, unilateral actions by the federal government and provinces. By contrast, in 2011 Australian jurisdictions agreed upon a coordinated plan, including national strategies and objectives on renewable energy, energy efficiency, adaptation and mitigation. How do we explain Australian success in achieving coordination, in contrast to Canadian failure over the same time period? While differences in political culture, geography, political economy and political leadership no doubt play a part, we suggest that the institutions of intergovernmental relations (IGR) in each country have had a significant effect on efforts to coordinate. Our objective is to explore whether there are meaningful differences in the institutions of IGR that create permissive or constraining conditions in these two countries.