Models used to test whether an environmental Kuznets curve (EKC) can be used to describe the relationship between GDP and energy use and/or carbon emissions may be biased by the omission of energy prices. Here we include real energy prices and fuel shares in models that describe energy use and carbon emissions. We test if these models show a turning point in OECD countries. Results indicate that including energy prices eliminates statistical support for a turning point and suggest that the relationship between income and both energy use and carbon emissions is represented most accurately by diminishing returns. These results imply that economic growth per se will not reduce energy use or emissions that cause global climate change.