In this paper from 1988, Bill Keepin compares the environmental and economic costs of nuclear power and energy efficiency in order to determine which option can create the most energy with the least impact. The analysis shows that while nuclear energy is an energy option with little carbon impact, it is not as effective, cheap, or reliable as energy efficiency. The paper concludes that while nuclear power offers a small contribution to the abatement of carbon dioxide emissions, the pursuit of nuclear power as a response to greenhouse warming is not a viable strategy because it is slow, expensive, and relatively ineffective. Meanwhile, improved energy efficiency is the opposite: quick, inexpensive, and highly effective. This report was submitted for the U.S. Congress’ Joint Hearing on Technologies for Remediating Global Warming