Earth Day, April 22, is a celebration of the practice of sustainability. But what is sustainability, and why should you care?

Sustainable development — growth and living — was actually was coined by a United Nations commission in 1987. Called the Brundtland Report, it says sustainability “is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Could you say you are living how your parents were? Or that we honestly expect that our children and grandchildren to live as we do?

We are a global economy, more so than when the first Earth Day took place in 1970. This benefits both sides, as we can trade for things unique to other lands and share our products with the world.

The bad news: When the planet is having a bad day, we feel the pain globally. The earthquake and tsunami in Japan is the most recent example. Beyond the devastation and enormous loss of life, the island’s troubles affect the world’s economy and touch our everyday lives. Do you have a Japanese car and need it fixed? You might have to wait a little longer to get those parts, as the intricate supply chain has been compromised.

Americans have long believed themselves “king of the castle” — at the top of the world economy — and therefore first in line for the world’s resources. It’s not always been the case, as it’s been mere centuries since we took it over from the Brits. And with developing countries like China and India dwarfing us in population and demanding a bigger share, there is a bit of pushing going on at the front of the line.

Today, everyone feels the pain at the gas pump. But how can a couple of little skirmishes in the Middle East affect our wallets? Why the high gas prices? Because the U.S. is only 5 percent of the world population but consumes about 35 percent of the world’s oil. We are a glutton and paying the price to have everything we want when we want it.

You might not like it yourself, but you better teach your children how to make it in the world with gas costing more than $4 dollars a gallon. Or how to manage with higher energy prices, or survive with high food prices.

As Americans, we need to drop the arrogance of world superiority and learn to live with less or expect to pay more for it. To live on this planet with less of an ecological footprint is the right thing to do. And if you don’t believe in altruism for the planet’s sake, the global evolution to less will be harder.

Sustainability is really training ourselves to live well with less. For Earth Day, it’s learning to live within our means and become more reliant on self-conservation — managing the resources we use every day.

• For a change: Recycle everything. Recycling is the fundamental step to making a change. It goes way beyond bottles and cans and encompasses everything we have in our hands before we throw it away. What would you have to do to reduce your waste to near zero? That’s the change we need.

• To make a difference: Buy recycled content products to close the recycling loop. Start with all your paper products — buy 100 percent recycled content. Don’t kill a tree for toilet paper, paper towels or copy paper.

• To make a stand: Compost. Grow your own vegetables. Use reusable water bottles. Use reusable bags at the store. Trade in your car for one that goes more than 30 miles per gallon. Get out of your car and walk and bike more. Take public transportation.

• Christina D.B. Frankel has lived in Tracy for more than 21 years and is an architect and mother of three. Her column, Living Green, runs every so often in the Tracy Press. She can be reached at cdfrankel@sbcglobal.net.