Major Challenges Ahead in Addressing Auto Emissions

Last Updated Nov 11, 2009 11:02 AM EST

Sales of BMW's new "eco-diesels," the 335d and the X5, were slow, so in August, the company offered a $4,500 "eco-credit" (modeled on "Cash for Clunkers") that, in effect, brought their prices in line with their gasoline equivalents. In part because the diesels are much more fuel-efficient, suddenly BMW had best sellers--the 335d (which also happens to be extraordinarily good and will conquer all your prejudices about diesels) and the X5 are now sold out until the end of the year.

German automakers wring their hands over American failure to appreciate the environmental value of new, ultra-low-sulfur diesels (far better for the planet than hybrids, they say), so this was very welcome news.

According to John DeCicco, an old hand at the fuel economy wars, such incentives are critically important if we're going to meet the tough new federal mandates. In some cases, consumers need a little push--and sweetened deals on what are usually price-premium automobiles is one way to give it to them. Here's DeCicco on video, talking about new ways of measuring the environmental impact of fuels: There seems little doubt that Congress will eventually pass strong climate legislation, though it may or may not contain the much-debated "cap and trade" provisions. Such legislative action is spurred by current events, such as the announcement this week by the Paris-based International Energy Agency that said, "Continuing on today's energy path, without any change in government policy, would mean rapidly increasing dependence on fossil fuels, with alarming consequences for climate change and energy security."

DeCicco, a senior lecturer on automotive issues at the University of Michigan, was speaking at "BMW University," a mostly green tech forum held at the company's headquarters in New Jersey November 10. He was full of interesting information about the daunting challenges--and opportunities--that await us in addressing fuel economy and global warming. It was interesting to learn, for instance, that coal is neck-and-neck with oil (and gaining) as a percentage of the global warming problem--and that most of the increase in oil demand (three quarters of which is for transportation) is coming not from the industrial nations, but from India and China. These countries are determined to follow the U.S. model in adopting private automobiles.

It's important to note, as DeCicco did, that light-duty vehicles are a much bigger part of CO2 emissions in the U.S. than they are globally. Our exceptionally high auto ownership means that what is 10 percent of total emissions globally is 45 percent in the U.S. measured separately. Cars and light trucks are 60 percent of transportation energy use in the U.S., but combine that with freight trucks and it's 79 percent. Airplanes are far more polluting than cars on a per-ride basis (lower your carbon footprint dramatically by reducing air travel) but they are only nine percent of the total problem.

Here's the coming collision. As DeCicco showed with a dramatic chart, the annual federal energy outlook--seemingly oblivious to headlines about rapidly advancing climate change--predicts basically steady-state (but creeping upward) CO2 emissions through 2040. But climate protection targets inherent in Obama Administration and international proposals demand dramatic reductions in that same time period.

"We've expressed the need for deep reductions by mid-century," DeCicco said. "But that's not reflected in the energy outlook--we're still on an upward trend with oil use and CO2 emissions." And until the recent recession, vehicle miles traveled (VMT) was relentlessly spiraling up, too.

The typical car traveling 12,000 miles per year emits 5.28 metric tons of CO2, which is two to three times its body weight. Over its lifetime, make that 50 times its body weight. DeCicco did reflect some good news for automakers. Air pollution from cars has been steadily declining since 1970.

Market forces by themselves are unlikely to curb U.S. auto addiction. High gas prices created record drops in VMT and a newfound concern about fuel economy, but when prices came down much of that evaporated. "Fuel prices are a fickle friend," DeCicco said. Some observers like the prospect of carbon taxes, but DeCicco said "politically, that's not going to happen, and it's hard to tax against the volatility of oil. Higher taxes and/or a carbon cap price signal would help, but it will not suffice when it's operating against the backdrop of high oil market volatility."

DeCicco, who pioneered "green scores" for automobiles while at the American Council for an Energy-Efficient Economy (ACEEE) proposes in a recent paper a new way of measuring the environmental benefits of biofuels. It's not enough to simply weigh the impact of the fuel itself (as is traditionally done with liquid fuels). A comprehensive strategy would also look at the total supply chain, including impacts on forests and croplands. He proposes, among other things, a land protection fund for purchasing international forest carbon offsets. He explains his proposal in much more detail in the video above.