This is one of a series of essays on contemporary environmental controversies. These issues may well define how or whether we can continue to live and improve our well being on this cosmic speck called Earth.

Control climate change; save the world. Continue to burn fossil fuels; destroy the earth. These are phrases heard frequently. I have used them in some form or other on a number of occasions. They don’t make any sense.

Our world, planet earth, has been around for 4.5 billion years. It was formed out of cosmic dust, gases, and energy in a process we marginally understand and that we can only marvel at.

Over the intervening eons, continents have shifted thousands of miles and oceans have risen to cover mountains and deserts before retreating again. The world has been exposed to ice covering much of the land mass and has seen tropical conditions at the poles. Volcanoes, earthquakes, and asteroid strikes have displayed forces on a scale that is only conceivable in a cosmic sense.

Throughout all of the history of the world, save for the most recent infinitesimally small sliver of time, humans have not been around to impact, or even witness, the massive transformations that have taken place in, on, and above the earth. The forces of nature and the laws of physics, either fully understood or yet to be unraveled, have brought the earth to the state we know today. Humans are merely late arriving interested spectators.

That may be changing. There are now over 7 billion people on the planet, each one striving to take enough resources from the natural systems to provide food, shelter and sustenance. We have collectively begun to make changes that previously would have been undetectable in the global sense.

Over the past 200 years, we have seen tremendous changes in the impact of humans on the world as we know it. This progress has resulted largely from harnessing the combustion of fossil fuels: coal, oil and natural gas. The by-product of this combustion, primarily carbon dioxide, is now accumulating in the atmosphere and oceans at a rate that rivals or exceeds anything seen in the geologic record over the past eight hundred thousand years.

Atmospheric carbon dioxide can be a game changer. Levels are rising year after year and global temperature increases are tracking the same trajectory. We are able to, and we are changing the world’s environment. Does this mean we are about to destroy the world? Not at all. We do outlandish acts against nature. The earth doesn’t care. The earth goes on.

When we talk about saving the world, we really mean preserving human life as we know it. We are talking about saving this one species out of the millions of species now existing on the planet. The planet doesn’t notice or care how many species exist.

Based on our meager knowledge of the cosmos and the extremely small part of it that we occupy, we presume the planet earth will disappear some day. This is a function of time and physics and is inevitable on a time scale of billions of years.

When the earth returns to cosmic dust and gases, all life will be extinguished. Until that time, some forms of life will continue on the planet, changing and evolving as necessary to adapt to then existing environmental conditions. The earth doesn’t care if the human species or any other life form survives.

We do care and we need to recognize what is happening and what needs to be done. It is in our self-interest to protect that part of the world that sustains not only ourselves, but also our children, grandchildren, and generations beyond.

We cannot save the world. We can reduce our reliance on burning fossil fuels. This will help extend the good life we know for a long time. However, there are no guarantees, whether measured on a human time scale or a cosmic one.

Only we can care. Only we can take actions to preserve the delicate environmental balance that will permit our one species to continue to function on the planet. We cannot save the world any more than we created it. We can be good stewards. We can make a difference.