When I was a teenager, my uncle would joke, "When all else fails, read the instructions." About the same time I also learned that the most important things don't come with directions for use. Our planet is a good example.

At a loss for guidance or a plan, year after year we consume the Earth's resources and harness its natural systems without much thought. Those who are concerned generally hope that our leaders will do what is best. But what if the people who know best are not the ones making the decisions, and today's leaders are so wedded to business-as-usual -- call it Plan A -- that they cannot conceive of a better way?

Or what if they are just too wrapped up in today's problems to worry about tomorrow's?

In any case, our options are limited. We can stick with Plan A, and hope human ingenuity pulls us through, or we can learn from our mistakes and change course.

Those ready for change will be glad to know there is an alternative, and even devotees of Plan A will be interested to read a recent book by Lester Brown titled "Plan B: Rescuing a Planet Under Stress and a Civilization in Trouble."

Brown is president of the Earth Policy Institute, a nonprofit research organization based in Washington DC. Additionally, he is one of the world's most respected environmental policy analysts, and his book is neither sensational nor fearful. It simply details the mistakes we are making and explains how we can get back on track.

"Plan B" is straightforward, easy to read, packed with examples and references -- and compelling.

"The world is moving into uncharted territory as human demands override the sustainable yield of natural systems. The risk is that people will lose confidence in the capacity of their governments to cope with such problems, leading to social breakdown," states Brown. He then explains why, using examples and statistics even the most science-shy can comprehend.

Readers may be shocked to learn how rapidly we are ravaging our habitat, but our ignorance is not surprising. Despite environmental decline worldwide, particularly in the developing world, the mainstream media has done a poor job of reporting the "big picture."

Population is a good place to begin. In 1950 there were 2.5 billion of us. Today we have topped 6.2 billion -- and all of us are consuming more than ever before.

But people are only part of the story. Brown notes that while world population has more than doubled, the global economy has grown sevenfold. It is little surprise that ecosystems worldwide are degraded. "We are cutting trees faster than they can regenerate, overgrazing rangelands and converting them into deserts, overpumping aquifers, and draining rivers dry. On our cropland, soil erosion exceeds new soil formation, slowly depriving the soil of its inherent fertility. We are taking fish from the ocean faster than they can reproduce," explains Brown, illustrating each point with examples from across the globe.

"We are releasing carbon dioxide into the atmosphere faster than nature can absorb it, creating a greenhouse effect. Habitat destruction and climate change are destroying plant and animal species far faster than new species can evolve, launching the first mass extinction since the one that eradicated the dinosaurs 65 million years ago," he adds.

Populations continue to climb and the global economy goes on ballooning. Put simply, our environment is like a bank account: If you keep a steady balance, you will reap steady interest. You can spend the interest, or reinvest it, and as long as you don't spend your balance it will continue to provide interest. Begin spending the principal of your savings, however, and eventually you go bankrupt. Unfortunately, we are now spending well beyond our environmental means.

Brown quotes a study titled "Tracking the Ecological Overshoot of the Human Economy" that was published by the U.S. National Academy of Sciences in 2002. The result of work by scientist Mathis Wackernagel and a team from Redefining Progress, a coalition of labor and environmental advocates, this determined that "humanity's collective demands first surpassed the Earth's regenerative capacity around 1980." The paper also estimated that "our demands in 1999 exceeded that capacity by 20 percent."

"We are satisfying our excessive demands by consuming the Earth's natural assets, in effect creating a global bubble economy," writes Brown. But he continues, "The good news is that there are solutions to the problems we are facing."

He offers suggestions for how we can raise water and land productivity and how we can cut carbon dioxide emissions by half, while stabilizing population and improving human health worldwide.

"The bad news is that if we continue to rely on timid, incremental responses, our bubble economy will continue to grow until eventually it bursts," warns Brown. "The stakes are high, and time is not on our side," he adds.

But Plan B is not as revolutionary as it might sound. It simply calls for us to look around, learn from what we see, and reorder our priorities before food and water shortages drive neighboring nations to war and the planet to ecological bankruptcy.

For example, is spending billions on military muscle the most effective way to subdue gangs of suicidal terrorists? Instead, why not "build a global society that is environmentally sustainable, socially equitable, and democratically based . . . one where there is hope for everyone," argues Brown. "Such an effort would more effectively undermine the spread of terrorism than a doubling of military expenditures."

So, consider Plan B for the holidays, and a Merry Christmas for generations to come.