The times where we forge along by taking as much as we can, believing that man is stronger than nature, are coming to an end.

A smell of blood, diesel fumes and sea salt was in the air. After what seemed an eternity at sea in the eyes of a 10-year-old boy, we pulled back to the harbor with two dozen bonito on board our lightweight sport fishing vessel. Bonitos are in the same family as tuna, but smaller. It was the summer of 1966. We proudly showed off our catch in the small village on the Italian Riviera, and because it was more fish than one family could eat, we gave away the rest, which was no easy feat since tuna, in the Mediterranean, was not regarded as a desirable seafood staple in those days.

Today, this would be a different story. Parallel with the rise in popularity of tuna, men have managed to overfish the oceans. That, combined with the oil spill in the Gulf of Mexico (one of only two spawning grounds for blue fin tuna), spells disaster. One of the few remaining wild food sources is about to be depleted. The end of tuna is in sight.

The catastrophe in the Gulf prompts me to write about “sustainability” this month. What once seemed a trendy word used by environmentalists, scientists and economists is rapidly becoming the way we all have to think and live; it is no longer a choice but an absolute must. For many species it is already too late, and that might include our own. My biology professor summed it up best by saying: “I’m not worried about nature; I’m worried about us.”

The many facets to the theme of sustainability (the capacity to endure) could fill a whole library. But I want to clarify that “sustainability” touches every aspect of our lives—not merely our interaction with the environment—and has far larger philosophical connotations than merely “going green.”

“And they were sure and certain, forever wrong, but always confident. They had no hesitation, they confessed no ignorance or error, and they knew no doubts.”

This is a quote from the novel “You Can’t Go Home Again,” written in 1940 by Thomas Wolfe, but it seems a fit description of the men in suits at BP oil. In the same decade this novel was written, a typical farmer would produce five calories of food for every one calorie of fossil fuel used; today, the average farmer produces one calorie of food using ten calories of fossil fuel. Now that is simply not sustainable!

We keep ignoring that the easy-to-reach oil reserves have been tapped and that future oil production will significantly increase the cost and the risks we take.

If the economic recovery seems as sluggish as the summer seems hot, we have to realize that much of our past economic growth was built on unsustainable deficit spending by both governments and households. That poses real long-term challenges, because the way we used to create “the perception of wealth” is simply no longer sustainable. It has now become so evident that we need to bring the U.S. household deficit under control that even politicians talk about it; part of the solution will have to include curbing military cost, which represents 23 percent of the total U.S. federal spending ($689 billion in 2009). Having nearly 300,000 active servicemen and women deployed in 152 states and territories around the globe is not only unnecessary, but simply unsustainable. To put it into perspective, the U.S. is single-handedly responsible for 50 percent of the world’s total military spending. Extreme Islamic ideology and the terrorists it produces continues to be a real threat to us and our allies, but the traditional weapon systems (like the F35) will do comparably little to protect us from this danger.

It seems that we have forgotten that we are one of the few countries that could be completely self-sustainable: We have enough natural resources, talent and factories to ignore the rest of the world, if we really wanted to. Yes, it would mean finding alternative and renewable energy sources, but eventually we will have to do that anyway.

It is unfortunate that we have not adapted any of the philosophical attitudes the Native Americans had: Take from the Earth only what you need. The times where we forge along by taking as much as we can, believing that man is stronger than nature, are coming to an end.

Before you fall into a depressive mood and start declaring that all is lost, consider it an opportunity. Making the Earth sustainable could very well be the next economic engine that will drive our economy into positive territory. After all, we have no other choice; and the faster we adopt this new attitude, the greater the chances are to become, once more, the Earth’s leading country and advocate. It is no coincidence that forward-looking companies and municipalities have started to hire chief sustainability officers… Onward!

E-mail your thoughts to Marc at mfrey@freymedia.com; or comment on his blog at www.hiltonheadmonthly.com/blogs.