Johnston cites numerous scientific findings that reflect much uncertainty about the roles of various climatic factors, such as the oceans, clouds, water vapor, airborne particles, the sun, and greenhouse gases. He advocates research to improve scientific understanding of global climate changes, but he says consumers should not have to pay for regulatory benefits that are speculative at best. Driving America also addresses other issues important to motorists, including new clean air standards from the Environmental Protection Agency, the deterioration of the U.S. road and highway system, and motor vehicle safety. Fuel economy rules reduce car safety. The government forces automobile manufacturers to produce smaller, lighter cars that provide less safety protection than do larger, heavier cars.
Studies show that the fatality rate in large cars is less than half the rate in small cars.
The science of global climate change does not warrant more car regulation. These involve solar output and the effects of oceans, clouds, water vapor, and other factors. Very little is certain. More fuel economy regulations would have virtually no effect on the climate. Emissions from motor vehicles in the United States are a small portion of human-induced carbon dioxide that itself comprises only a small fraction of all releases of greenhouse gases.