Rob Jackson is associate professor of environmental science and biology and director of Duke's Program in Ecology.

When he turned 70 my grandfather quit paying taxes. There is something amusing in the image of an old man thumbing his nose at the government. Not paying was an act of rebellion, but he also just didn't like keeping records. I asked him once why he did it. "I don't know," he replied. "First it was only a few days, then a week, and before I knew it months and years had gone by. It was easy. Deep down inside, though, I knew better."

Recently those words kept coming back to me. I wondered why, and now I think I've figured out the answer.

They're the perfect metaphor for our relationship to the environment. Deep down inside, we know better.

The environment is like a car. Maintain it properly and it serves you well for a long time. Abuse it and it'll cost you.

Once I had a roommate who couldn't be bothered changing the oil in his car or even checking it very often. Beer money was more important. (And as his roommate, I certainly agreed.) He rationalized his choice by saying, "What are the chances that the car will break on the very next trip? Really small, right? Small chances don't happen very often."

Eventually, one perfectly normal day, he got in his car, rolled snake eyes, and his engine burned up. His parents, who had helped him buy the car, didn't view the money he'd "saved" in quite the same way. Deep down inside I think he knew better.

We should, too, when it comes to environmental problems like global warming. Physicist Jean Baptiste Fourier first described how greenhouse gases warm our planet in 1827. In the 1890s Svante Arrhenius and P.C. Chamberlain both outlined how a buildup of carbon dioxide from burning fossils would warm the Earth.

Two hundred years later we still pretend that such ideas are "new" or "uncertain," that we really don't understand the Earth well enough to act. We also pretend it's too expensive to act, just like my roommate did. Deep down inside I think we know better.

Fixing environmental problems can take lifetimes. When carbon dioxide reaches our air, it typically takes a century or more to disappear, and there is little we can do about it. Global warming will thus continue for decades, even centuries, after we eliminate the pollution causing it. Our grandchildren deserve better.

Companies like BP Amoco and Royal Dutch Shell have already stated that we should act. The question is how.

Last year California became the first state to pass its own greenhouse gas plan. Controversial bill AB 1493 sets emission targets for vehicles made after 2008, factoring in cost and technical feasibility. Why is California doing it? For future generations and for people today -- lower emissions mean lower pollution right now. We should be discussing whether a similar bill makes sense in North Carolina.

Increasing fuel efficiency is another obvious goal. Hybrid cars routinely get 50 miles to the gallon and never need to be plugged in. Why aren't we acting? By ignoring fuel efficiency and the Kyoto Protocol, we play right into the hands of countries who claim that war in Iraq is all about oil.

Finally, we need a broad-based carbon tax to give people and companies incentives to conserve. The tax should be revenue-neutral, a dollar out for every dollar in. I have no desire to give the government billions of dollars, and neither did my grandfather.

Ultimately, of course, he paid. It took the government more than a decade to catch him. When they did, he paid the original bill. He paid interest. He paid penalties, liens and fees. He paid in spades.

Perhaps what hurt him most, though, was that his children paid too. My uncle spent months trying to reconstruct his financial records. How ironic that my grandfather's stubborn independence ultimately made him depend completely on his children to fix the problem.

Deep down inside he knew better. So should we. If we keep pretending that the bill will never come due, our children will be the ones picking up the tab.

This article originally appeared in the March 8 News and Observer