[Noozhawk’s note: First in a series.]
At some point during our middle school years, we all get an education in the Physical and Life Sciences that sets a baseline for understanding facts about our solar system (or not).
Can you remember how far the Earth is from the sun, whether the sun’s radiance is modified by Earth’s orbit, what were the durations and causes of historical glacial and warming cycles, what is the most prevalent greenhouse gas?
I get an occasional chance to talk to high school students, through various volunteer opportunities, and ask these basic questions. In many cases they get lost in the details.
But what does come across in our everyday talks is that our Earth is burning up, man-made fossil fuel emissions are the root cause … settled science, case closed. Some have already changed their carbon footprint, many are leaning in, and others either are resisting or waiting until push comes to shove.
But the resolve of rushing in “green” new alternatives at lightning speed — with price tags beyond comprehension — does deserve a lot more discussion before the keys to the economy are turned over.
We should never lose sight of the facts, or causes/effects, and be sure to not start creating solutions looking for a problem if we don’t know the underlying problem(s).
So, this four-part series will lay out some facts and data about the history of our solar system, planet Earth and the various ingredients of life in a constantly changing world.
Part 1 will address Earth and its relationship with our solar system. Part 2 will focus on both historical climatic periods and global warming in the pre-Industrial Period. Part 3 will dive into life on Earth from several millions of years ago and into the Industrial Revolution through today, including man-made greenhouse gas emissions. Part 4 will explore alternative energy solutions, cost/benefits, and the challenges current and future generations will face.
For the record, yes, Earth is in a warming period that is estimated to continue for a long time into the future (upward of 5,000 years) and that must be better understood by all.
I’m a layman and not an expert in any of the fields of science that are presented throughout this series (but sources are footnoted for reference). The Novim Group at UC Santa Barbara has participated in reviewing this series.
Part 1 — Earth Science and our Solar System
Back in the sixth century, the Greek mathematician, Pythagoras, described our Cosmos as “an orderly or harmonious solar system.” But it’s hard to envision that some master planner created our solar system with purpose of mind.
The Big Bang, 14 billion years ago, was the genesis of the solar system. However, our solar system really began to take shape from spinning clouds of dust and gases bound together with tremendous gravitational pull, some 4.6 billion years ago.
With gravity collapsing on itself, our sun formed the center of this solar system and new terrestrial bodies (including planets) aligned with their respective geologic makeups and spinning orbits.
Let’s start with the sun. This star is so big, 1 million Earths could fit inside. It is our heart, producing natural source of heat and light through nuclear fusion.
With a core temperature of 27 million degrees Fahrenheit and 11,000 degrees at its surface, it is not too hot, not too cold. However, the sun has numerous sun spots (temperatures about 30% cooler) and periodic solar flares.
It’s at its half-life and getting hotter. Astronomers estimate its’ luminosity will increase ~6% every billion years.
So, what makes Earth habitable? Fortunately, it’s the right distance from the sun, protected from harmful solar radiation by its magnetic field, kept warm with greenhouse gases in the atmosphere, has the right chemical ingredients for life (which includes lots of water and carbon).
We are 97 million miles from the sun during its most perfect orbit cycles, with the photons emitted from the sun taking 8 minutes to reach Earths’ atmosphere.
On average, 70% of sunlight is absorbed by the atmosphere with 30% reflected back to space. Scientist call this the “radiative equilibrium,” in which Earth is neither gaining nor losing energy.
Our moon is as important to life on Earth as anything the cosmos created. Many researchers believe the moon’s gravitational influence helps to ensure the stability of Earth’s spin axis’ tilt angle.
Why you ask? Because, as Jeremy Bergman wrote in a 2018 article, “The Moon: Required for Life on Earth,” for the Institute for Creation Research, “Earth’s remarkable stability is due to the combination of our large moon and its nearly circular orbit. One of these two traits alone could not produce the stability necessary for life; both are required.”
The other takeaway benefits of our moon are time, tides, light and darkness.
But back to Earth and a couple of factoids worth recording. There are three major layers in our globe, starting with the center core (15% of Earth). It’s mostly iron-nickel alloy, very liquid and get this, it’s upward of 10,000 to 11,000 degrees. (Note to self, the center of Earth is as hot as our sun but only 4,000 miles from its surface.)
Next, the lion’s share of Earth’s layers is the mantle, at 84% by volume. Both molten rock (minerals found in the periodic table) and magma, which is both liquid and molten rock that when it surfaces becomes lava (both upward of 2,000 degrees). Lastly, is our crust that, interestingly, only accounts for 1% of the entire globe.
Our oceans make up more than 70% of the crust’s surface, with the Pacific Ocean being about one-third of the planet, larger than the entire landmass of all continents.
The oceans average a depth of 12,000 feet and were mostly unexplored until recently (less than 10% has been explored below 3,000 feet). In 2000, a program called Argo launched robotic floats in oceans to record measurements, which will vastly improve our understanding of changing conditions.
Also relevant, there are more than a half-dozen large tectonic plates covering Earth in constant motion. In our corner of the world, are the Pacific and the North American plates, disconnected by what’s known as the San Andreas Fault.
About 15 million years ago, these two plates had one of the largest earthquakes known, with the Sonoran Desert at the epicenter. Since then, the Pacific Plate has continued to move north at a rate of 1½ inches a year (Santa Barbara County started its journey back then in Mexico).
One more matter to mention is that the Earth’s fossil fuels also reside in the crust. No, oil and gas are not exactly dinosaur remains, but are the biproduct of plants and animals decomposing hundreds of millions of years ago. Pressure and heat changed their remaining compounds into hydrocarbons and other organic compounds.
Let’s close with Earth’s atmosphere. Many celestial bodies have their own makeup of gases, but those gases in our atmosphere (which extends almost 6,000 miles from our surface) allow for life as we know it.
There are seven layers, which hold varying degrees of these gases that are held in place with the gravitational forces surrounding our globe. In summary, dry air molecules are made up of oxygen (21%), argon (1%) and greenhouse gases (less than 1%) on average.
However, we need to better understand the most important greenhouse gas, water vapor, which represents on average 75% of total insulation in the atmosphere. The other greenhouse gases are natural CO₂ (~10.5%), methane gas (~9%), fossil fuel emissions (~4.5%), and other (~1%).
And, as phsyicist Steven Koonin outlines in his book, Unsettled, “greenhouse gases in the atmosphere intercept and impede the flow of infrared heat from the earth’s surface into space,” they do not trap heat.
In summary, our world was beautifully created to give us life while protecting us from no life. It’s complex, mysterious in its evolution, but full of repeatability.
All of our sciences can and should continue to help us map its recipe, while better understanding man as an influencer in our quest for knowledge and corrective actions when required. Part 2 will explore the causes and effects of global cooling and warming, historically to the present.
— Michael Rattray is a longtime Santa Barbara resident, retired after 34 years in the defense industry. Today, active in both the preservation of Goleta Beach Park and the restoration of the Goleta Bay macrocystis (sand-dwelling kelp) forest lost during the 1982-1983 El Niño. Click here to read previous columns. The opinions expressed are his own.