As the world marks the 43rd Earth Day today, inhabitants face the question: How can we live on the planet without destroying it?

We needn't ask whether climate change is real - decades of research gleaned from shrinking ice caps and rising temperatures have already established that. Nor can there be any doubt that the global population of 7 billion (and growing) strains food and water supplies, contributes to air pollution and accelerates habitat destruction, thus driving countless plant and animal species to extinction.

Even as Western nations continue to consume a gluttonously disproportionate share of the world's energy and natural resources, burgeoning overseas' economies are catching up fast. While it's tempting to throw stones at China and India for sacrificing environmental principles on their paths to prosperity, the United States is hardly without sin.

For too long Americans have behaved like characters in the "Tragedy of The Commons," a classic example in which livestock owners, free to raise their animals on public land, put more and more of them out to graze. Eventually the animals eat all the free grass and everyone suffers.

Similarly, if everyone scrambles to thoughtlessly exploit such "free" resources as air, water, natural gas and oil, all eventually lose out.

Until individuals strive to support a more sustainable economy, there will always be the specter of such environmentally costly projects as the Keystone XL Pipeline, which would expand oil and natural gas development on public land and force construction of new railroads and deepwater ports for shipping coal from mines in Montana and Wyoming to China and other overseas destinations.

There also will be growing pressure to expand oil exploration offshore and in such environmentally sensitive public regions as the Arctic National Wildlife Refuge.

Simply put, Americans must learn to curb their enormous appetites for energy.

While government and industrial leaders can pass stricter regulations and produce more efficient products, average citizens can take steps to help reduce power consumption.

They can save gas by riding bikes instead of cars; save energy by living in smaller, energy-efficient homes; decrease demands on water, land and energy needed to grow food for animals by cutting down on meat consumption; and minimize future waste by eliminating unnecessary consumer purchases destined for landfills and municipal incinerators.

Unfortunately, many consider such reasonable practices as burdensome sacrifices.

The late Ruby Turner Morris, a former New London mayor, encountered scorn when she first suggested implementing a recycling program in New London back in 1979. These days, most people know to set aside their plastic bottles and paper products, and it has become another part of day-to-day life not just in the Whaling City but in virtually every municipality in southeastern Connecticut - not to mention the entire state and much of the country.

Mrs. Morris also overcame resistance when advocating creation of a mass transit system, and today, while Southeast Area Transit buses aren't always full, they are a familiar sight throughout the region. More people must learn to get away from their cars, if not to ride a bike, at least to start taking the bus.

Just as all of us should question how government regulations and corporate decisions affect the environment, we must also consider how our own actions influence it for good or ill. We must devote more creative energy into saving energy.

When human beings, acting as individuals as well as in communities, apply such creative energy to such worthy aspirations they often come up with positive solutions.

In an ideal world April 22 wouldn't be different from any other date on the calendar. Every day can be Earth Day for those who make thoughtful decisions about how to live their lives.