Vehicles of the near future.

• Author: Johnson, Geoffrey

The same can be said of the transportation sector generally. Americans drove 2.8 trillion miles in 2000, up 35 percent over 1990 levels. And, unlike Robar's fleet, we are driving ever bigger cars. Outside our big cities, public transit is either poor or non-existent. These trends are why transportation is now the fastest growing source of global warming gas emissions in the U.S.

Clearly, America's attitude must change regarding our dependence on cars. Meantime, some answers to the economic and environmental concerns of Robar--along with commuters and businesspeople throughout New England--are now emerging. What would Robar say if, within just a few years, he could own a fleet of "clean cars" that would consume 30 percent less gas and generate 30 percent fewer emissions?

"It would be wonderful," Robar exclaims.

Spurred on by CLF's advocacy, a new generation of clean cars is in fact on its way to New England. Under new rules recently adopted in every Northeastern state bur New Hampshire, automakers must--for the first rime in history--start reducing greenhouse gas emissions from motor vehicles. The rules were supported by op-eds, public testimony and other efforts by a team of CLF advocates, and will reduce vehicle greenhouse gas emissions by an average of 30 percent by model year 2016.

These new rules should not be confused with the growing attention being paid hybrid gas-electric vehicles. In fact, not all hybrids will qualify as clean cars. Compact hybrids like the Toyota Prius and the Honda Civic are highly efficient, low-emissions performers. But the Honda Accord with 255 horsepower (more than a V6 Ford Mustang) and the 268 horsepower Lexus RX get scarcely better gas mileage than their conventional counterparts. Even if all hybrids were super-clean, last year hybrids represented less than 2 percent of passenger vehicle sales nationwide. With such a small percentage sold each year, for now, hybrids will do little to tackle global warming.

Automakers have their choice of technologies to meet the new standards--all that is required is that every year, starting in 2009, they continue to reduce the overall emissions in the car fleets they manufacture, until they reach between 25 and 30 percent reductions, depending on vehicle class.

There are two primary ways to cut vehicle emissions: by designing more efficient engines and by using better transmissions. Engine improvements include, for example, cylinder deactivation, which can turn a V8...