The magnitude of the glacier is overwhelming. Miles of ice roll in solid waves, a frozen monument to the incomprehensible immensity of time. It makes the knowledge that these massive blocks of ice are disappearing all the more staggering.

Common wisdom, and most science, holds that cracking Arctic ice shelves and melting glaciers are the handiwork of Homo sapiens sapiens. Other people claim that warmer temperatures and melting ice are simply part of the natural cycle of the Holocene, and of even broader climate patterns that have occurred for hundreds of millions of years.

But as Earth Day approaches, and the din about environmental issues becomes louder, It’s clear we have a problem. Whether or not you believe human activity is the cause of global warming, we’re gobbling up resources and polluting this planet at an unsustainable rate. And I mean precisely that?unsustainable. Some estimates give us only 10 or 15 years before the damage becomes irreversible.

Like the size of the glaciers, the problem can seem overwhelming, and as I look at my small pile of recycling I can’t help but wonder?does the careful sorting of my little bundle of papers really make one bit of difference in the big picture? Does that one-less plastic bag at the checkout truly matter when it comes to overflowing landfills and staggering levels of industrial pollution?

The answer is yes, it does. And That’s because the key to keeping our little blue planet habitable lies in the same place that caused the problem: sheer numbers. It took millions, and then billions, of us one discarded pop can, one thrown-out keyboard, one bag of Christmas wrapping at a time to get here. The sprawling landfills and rivers of deadly chemical cocktails didn’t appear overnight. We created them?are still creating them?every time we toss out that plastic packaging from our new gadget, or choose to buy carpets and clothes and furniture from people who don’t care how much waste their companies produce as long as they make a buck.

The term critical mass is overused (and usually sounds like It’s right out of a bad political thriller), but it fits the image I have in my head: my tiny pile of recycling multiplied billions upon billions of times. The lone plastic bag I don’t use, stacked in imaginary piles, one for each of the millions of people who decide they don’t need one more piece of petroleum jammed into a kitchen drawer.

The only way we’re going to get out of this is the same way we got into it: by making thousands of small choices that add up to overwhelming results.

The big choices count too, of course they do, and major efforts by governments and industry should be demanded. The results can be seen in places like the River Thames. Considered ?biologically dead? just 50 years ago, seals and dolphins have been spotted in it as the result of clean-up efforts, and the river ?is filled with eel, sea bass, flounder, mullet, lamprey and sole.?

Whether or not you agree that we’re making our home hotter, there’s no arguing that, together, we’ve polluted the water, clear-cut the forests, and fouled the skies. Proof that on Earth Day, and every day, the small choices we make do matter?a million times over.