AS greenhouse gas emissions from human activities continue to increase; it has become clear that our current trajectory is not sustainable. It is also apparent that current state, national, and international policies individually are not sufficient to meet the greenhouse gas emissions reductions recommended by the Intergovernmental Panel on Climate Change (IPCC). The fourth assessment report by the IPCC calls for greenhouse gas emissions rates that are 50%-80% of those experienced in year 2000 in order to stabilize atmospheric carbon dioxide levels . It is my hypothesis that from a life cycle perspective, one vitally important factor that has the potential to reduce greenhouse gas emissions more rapidly than the integration of renewable and low carbon energy sources into our energy production mix is energy efficiency improvements by industrial, commercial, and residential consumers. Further research using life cycle assessment models illustrates the effectiveness of well constructed policy that stimulates real energy efficiency improvements as part of a long term comprehensive plan to reduce greenhouse gas emissions. It is also used to determine whether policies that encourage energy efficiency improvements, for example mandatory carbon labels for products, are more or less effective at meeting greenhouse gas reductions in both the short term and long term future than other popular current or potential policies and technologies such as low-carbon fuel and renewable energy mandates.