Every year on Earth Day, we're supposed to reflect on all the ways we've made the planet worse.

But what if we try something different? What if we reflect on all the ways we've made the planet better?

Try this thought experiment. Imagine that we transported someone from 300 years ago

at the very start of the Industrial Revolution to today's world.

What would he think about our environment?

Without question, his reaction would be one of disbelief.

Not that we had destroyed his pristine natural world, but that such a clean, healthy environment was possible.

The air is so clean our time traveler might say.

Where I come from, we're breathing in smoke all day from the fire, we need to burn in our furnaces and stoves.

And the water. Everywhere I go, the water tastes so fresh and it's all safe to drink.

On my farm, we get our water from a brook we share with animals and my kids are always getting sick.

And then the weather, I mean the weather isn't that much different, but you're so much safer in it.

You can move a knob and make it cool when it's hot and warm when it's cold.

And what happened to all the disease?

In my time we had insects everywhere giving us disease.

My neighbor's son died of malaria and you don't seem to have any of that here.

What's your secret? I'd tell him that the secret was energy, specifically energy derived from fossil fuels, oil, coal and natural gas.

These fuels power machines that allow us to transform our naturally hazardous environment into a far healthier environment.

Most of the natural world is too hot or too cold, as too much rainfall or not enough.

Then there's bacteria filled water, disease-carrying insects, tornadoes, earthquakes and tsunamis to name just a few of nature's unpleasant features.

As our time traveler noted, 300 years ago, human beings spent a lot of time breathing polluted air from indoor fires.

As unhealthy as it was, it was worth the warmth.

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