Professor Ann Carlson spoke with the Los Angeles Times on the possible effects of rolling back fuel economy standards. If nationwide gas-mileage standards are indeed rolled back, the country could lose an important bulwark in keeping the popularity of gas-guzzling vehicles from driving emissions up. “For many, many years until these standards were issued we saw no increase in average fuel economy," said Carlson. “Now we're seeing many more models that are either zero-emission or very high-economy hybrids. We see larger cars getting more fuel efficient and regular combustion engines getting more fuel efficient. I don't think that happens without government regulations."