Sunday is the 42nd anniversary of the creation of Earth Day, a remarkable movement founded in Madison, WI by then US Senator and former Governor, Gaylord Nelson.

Earth Day has one central purpose: to encourage people to consider humanity’s impact on the environment and act in ways that reduce the negative effects on all ecosystems and species.

It is a simple goal, but has far-reaching implications and can be summed up in their most-recognized slogan, “Think Globally. Act Locally.” It was Senator Nelson who coined this idea, insisting that local action and education be the central method of Earth Day rather than protests and sit-ins.

“Act Locally” does not just mean in counties or municipalities, it means in our homes and businesses, and most importantly, our lives. Sure it means big things like urging local, state, and federal governments to pass laws that protect our environment, but it also means smaller things like being realistic about what we need to consume, buying more efficient homes, cars and appliances, driving more-efficiently, and reducing water waste. It means reducing what we consume, reusing as much as we can, and recycling what we can’t.

But mostly, it means the really little things that we don’t usually think about. Things like choosing your household chemicals carefully, despite the price difference, and disposing of them safely, rather than conveniently. Or trying not to buy things with limited need or use, or just for the sake of buying. Or considering the practices of the businesses you patronize, the shows you watch, the magazines you read. It means bringing reusable bags to the store when you go shopping. It means composting your biotrash and reducing your overall waste. It means turning off lights, and turning down the thermostat. It means picking up dog doo with actual biodegradable plastic.

It means letting the impact of you and humankind become a factor in how you make choices every day.

The truth is, Earth Day isn’t about the Earth at all, it’s about us. It’s about taking the time to reflect and realize and accept that we’re all part of a growing global community. And what we buy and how we act actually does affect every other person and species on the planet, most of the time without us realizing it, especially here in the United States.

Behind all the product marketing, conspicuous consumption, and infused necessity, there is the cold, hard truth that our citizens use and waste more than almost any other community on Earth. And since we have the wherewithal to buy lots of stuff, everybody around the globe will sell it to us, which makes it even harder for us to discover that the low-cost product we buy today, and its packaging, may be directly destroying rainforests in Sumatra, clogging the gullets of sea-birds in the Midway Islands, or poisoning our very own water supply. And of course, the “free” plastic bag you carry it home in will probably end up swirling in a mass of trash in the center of the Pacific Ocean.

Earth Day is about recognizing this worldwide inter-special community and accepting responsibility for it. That, and committing to change.

If all of us changed just one thing we do, knowing that if everyone did it, we’d be better off, it would have a considerable effect on the whole. If we all changed two things, it would be twice as effective.

So I encourage you to take a few minutes to read about the history of Earth Day and Senator Nelson. There is great history in what Earth Day was in its infancy, as well as what it has become.

Then maybe, just maybe, we will all be inspired and motivated to change one thing in our lives that we have always known wasn’t environmentally responsible, but never had the guts to commit to. And once you change it you’ll feel better about your impact on the world, and perhaps that will inspire you to change another thing, and then another, and another. I know, because I strive to do it every day.

Consider the planet, and its plethora of species. Consider the wild places and how they’re shrinking. Consider humankind’s power to influence, poison, ruin, or protect our environment. Consider our fellow humans living halfway round the world using a fraction of the resources and products you’ll use today…and surviving.

Please take care of our planet’s ecosystems. This is your home, and the home of everyone and everything you’ve ever loved and everyone and everything you ever will.

Think Global. Act Local.