Under conditions of conflict and uncertainty, forging a new constitutional consensus is a monumental task. If we hope to address climate change through a new global constitutionalism, we must challenge current approaches to assessing the costs, benefits, and uncertainties of environmental regulation, and arrive at an international consensus regarding those approaches. In doing so, input from experts in a variety of fields should be sought. A positive example of this approach is the Intergovernmental Panel on Climate Change’s inclusive and democratic process of environmental assessment. However, we must avoid abdicating responsibility in favor of complete reliance on experts, and remind ourselves that expertise—legal or scientific—should be questioned and tested by democratic participation.