A mechanical engineer by training, Roland Hwang is NRDC's transportation program director. He works on transportation, energy, and climate issues at both the state and federal levels.

Last year President Obama announced a national program to cut auto emissions. How does this relate to the administration's overall climate policy?

There are two critical aspects to the program. First, it will be an important step toward the pollution reductions needed to avert dangerous levels of global warming. Second, it demonstrates that what seems at first politically impossible-in this case, getting agreement among regulators, automakers, and environmentalists-can actually be achieved if all parties work productively and in good faith toward a solution. So we see the program as helping to pave the way for an agreement on an economy-wide cap on carbon.

You have been a long standing critic of the Detroit automakers for being overly dependent on gas guzzlers. Is that fair given the large profit margins they were making on SUVs and the fact that nobody could predict that oil prices would hit $140 a barrel?

In 1995, just as oil prices were starting to rise, I co-wrote a report called In the Tank: How Oil Prices Threaten Automakers' Profits and Jobs, which showed that Detroit Big Three profits would take the brunt of higher oil prices if they continued to ignore the risks of a potential for oil price shocks. Unfortunately, the reaction of the Detroit automakers was to dismiss our warning as alarmist, especially since it threatened their business model. I didn't have any special information or insight into the world oil markets that was unavailable to Detroit. Perhaps not surprisingly their economists ignored what was becoming increasingly plain to oil experts, but it was a message that the Detroit executives simply did not want to hear. We met with their economists face to face and they were, literally, in a state of denial.

The automakers have been claiming for years that requirements for cleaner, more fuel-efficient cars would hurt their industry. With higher fuel prices and rising demand for fuel- efficient vehicles, have they changed their perspective?

It's almost certainly true that their marketing departments "get it." When you see Howie Long extolling the fuel economy of full-size GM pickups during the Superbowl, you know that something is different. However, the question the OnEarth article raises is whether this short-term change in advertising heart will actually result in a long-term transformation of their corporate "DNA." If gasoline prices dropped overnight to $1 or $2 a gallon, some companies would gladly go back to selling gas guzzlers. In fact, this is exactly what happened during the 1990s when-it's hard to believe-oil actually dropped to $10 a barrel and gasoline was $1 or so a gallon. All the lessons of the first two oil shocks during the 1970s were lost, not just on Detroit but also on other companies like Nissan and Toyota, in a short-sighted rush to cash in on what seemed like an endless appetite for bigger, more gas-guzzling vehicles.

Wow, that seems like a scary (if realistic) prospect. How do we avoid history repeating itself?

Unfortunately, unless we take the right actions, we will continue to cede control of our economic and environmental destiny to foreign, oil-exporting countries, concentrated in the most politically volatile region of the world. Ironically for Detroit after years of fighting standards, what they most need is regulatory certainty and a clear, long-term signal that fuel economy and CO2 standards will be gradually and continuously strengthened over time. Without such certainty, the temptation is too great. Stronger, longer term standards actually act as an industry-wide "hedge" against oil price volatility and by requiring the entire industry to engage in the same strategy, you eliminate the risk that one automaker may face if it embarked alone on a higher fuel economy strategy. This is the unfortunate pressure that Honda was under since at $10 or $25 a barrel oil, it pays to do the wrong thing, at least in the short term. And of course, stronger standards reduce global warming pollution, enhance energy security, and create thousands of clean energy jobs.

So was it a good investment of our tax dollars to bailout GM and Chrysler?

Quite frankly, I'm not sure if we had much of a choice given the state of the economy. But it's clear that the auto industry globally is facing unprecedented structural pressures-global overcapacity, a decline in cheap financing, and continued pressure on fuel economy and CO2 standards. The old business model doesn't work; automakers have to find a way to become leaner and profitable selling clean cars, both smaller, more fuel-efficient vehicles and advanced technology vehicles such as plug-in hybrids. Companies like Honda have a head start. The Chinese are trying to leapfrog the existing industry by going directly to electric cars. I was just in Beijing last year. The progress they are making is scary. GM and Chrysler must remake themselves or die. I'm cautiously optimistic they can make this transition, but it's a tough road.

Finally, not everyone can afford to drive a hybrid. What recommendations would you give to our readers?

I get that question a lot. For some people, the current hybrid offerings don't fit their budget or what they think they need. My advice is always first and foremost, "right size" your vehicle. That is, don't buy one that's bigger than you need for 95 percent of the time and don't take the fuel economy hit of a 4-wheel-drive vehicle if you only use it on rare occasions. Rent a minivan or a 4-wheel-drive vehicle for those occasional trips. And I never thought I would be saying this, but for some folks, a new "clean" diesel offered by many of the German manufacturers might be a very good choice. My personal vehicle is a conventional Honda Civic and we have two boys. The most environmental thing I do on a daily basis is to leave it parked in my driveway while I take the bus across the bay to San Francisco.