Climate change will have highly significant and largely negative effects on human societies into the foreseeable future, effects that are already generating ethical and policy dilemmas of unprecedented scope, scale, and complexity. One important group of ethical and policy issues raised here concerns what I call
environmentalvalues. By this I do not mean the impact that climate change will have on the environment as a valuable human resource, nor am I referring to the changing climate as a threat to humans in terms of floods, storms, and droughts, important as these are. Rather, I am concerned with the way climate changeand the policies that may be adopted to respond to itthreatens both things we value and, potentially, some of our environmental values themselves.