“What if the Earth…
…with all its cargo of advanced animals is virtually unique in our galaxy, the most diverse planet in the nearest 10,000 light years, or even in the visible Universe?”
In 1974 Carl Sagan, the renowned astronomer, estimated that a million civilizations may exist in the Milky Way galaxy alone. There has been much progress in scientific thinking since then.
Professors Peter Ward (Geology) and Donald Brownlee ( Astronomy) , both at the University of Washington, co-authored “Rare Earth: Why Complex Life is Uncommon in the Universe”. Quoted above, and again here: “Not only intelligent life, but even the simplest animal life is exceedingly rare in our galaxy and the Universe. While microscopic organisms might be common in planetary systems, the evolution and long term survival of complex and even intelligent animals is rare.”
There was no oxygen in the atmosphere until about halfway through the estimated 4.6 billion years of Earth’s existence. First life consisted only of anaerobic microorganisms, one celled life that very slowly evolved into multi-celled life forms. It wasn’t until the Cambrian Era 540 million years ago that fish and other water animals developed. It has only been since about 250,000 years ago that home sapiens appeared on Earth. That’s a staggering amount of time since life first appeared. How often can life, as we know it, occur in planetary systems?
Now 7+ billion humans have become the dominant life on Earth. They/we are now a “force of nature”, altering Earth’s atmosphere, landscape, fresh water supplies, and ocean chemical composition. Humanity is affecting the very conditions that have been needed to nurture and sustain all animal life. Some say we are collectively conducting “The Grand Experiment”, to see if 7 ( or 8, or 9?) billion humans can survive with enough food, water, and air as we play havoc with Mother Earth. Earth has provided enough benevolent conditions for life to begin, evolve, and diversify over immense spans of time.
As we each deal with day to day decisions and activities here in Panorama, few of us give much thought to the astounding conditions, events and changes in our earthly environment that have culminated in our exceedingly complex internal organs, systems and brain cells that have taken billions of years in the making.
Aside from being grateful for the fulfilling years we’ve had, what can an individual do to honor, respect and care for the Earth? Green Team members offer some suggestions:
* Reduce further exploitation of natural resources by recycling and reusing paper, plastic, metal and
glass. Special praise to the Benevolent Fund as the supreme recycler of “all things household”.
* Use less fossil fuel for “getting around”, using the many transportation opportunities available on
campus and in Lacey.
* Limit/reduce/eliminate the use of poisons in agriculture and landscaping so as to achieve healthy
food, soil and air.
* Promote the healthy presence of insect pollinators so crucial to the germination of the vegetables
and fruits that we eat and the flowers that we enjoy. Example: The new Pollinator Garden.
* Learn more about environmental issues both local and national through educational videos and
programs offered during the year.
Adding to our perspective as humans on Earth, Ward and Brownlee identify 18 “rare earth factors” that have enabled single cell Achaean life forms (that first appeared about 700 million years after Earth originated) to have ever so slowly evolved into multi-celled organisms and even more slowly into more complex life. A brief sampling includes:
* A sun that has provided continuous energy and heat on Earth for over 4.6 billion years (not common in the Universe).
* The position of Earth in the “Habitable Zone” in the solar system, assuring plenty of liquid water and warmth.
* An unusually large moon which stabilizes the 23 degree tilt, providing moderate seasons and vital tidal zones for the oceans, and assuring a constant rotation rate as Earth spins on its axis.
* Plate tectonics, fueled by heat from Earth’s core of iron, nickel (and uranium) to build land masses and mountain ranges for life to diversify into complex animals.
* The evolution of oxygen as a “waste product” of stromatolites in huge quantities for both the seas and the atmosphere.
* Photosynthesis in plants that provide food for animals and complex mammals like us.
* Very few giant impacts from asteroids and comets which have caused varying degrees of mass extinctions (about 15) but never a complete sterilization of all life.
Many “fortuitous events” have occurred that have brought about opportunities for animal life to survive and expand such as the famous Chicxulub Impact in Mexico 65 million years ago that ended the era of the dinosaurs and made it possible for mammals (and rodents) to thrive. Oxygen and CO2 levels have risen and fallen dramatically over immense time spans, and still life has survived.
Ward and Brownlee now pose this question: “Will the emergence of any intelligent species co-opting a planet’s resources in the service of technology and agriculture cause a planetary mass extinction?”
An answer appears a few pages later: “There appears to be abundant evidence that this is now underway on Earth”.
If the Earth is utterly unique, “how much greater the loss the Universe sustains for each species of animal or plant driven to extinction through careless stewardship of Homo Sapiens?”
There are thousands, hopefully millions around the world, very concerned about our collective future on Earth. We join them in our small community with many opportunities to improve our stewardship. Ward and Brownlee provide pertinent perspective to our thinking.
Bill Seelye, Panorama Green Team
Reprinted from the October 2015 Panorama News