Fossil Fuels and Global Warming & Climate Change
The preeminent paleontologist Peter Ward has said that all mass extinctions on planet
Earth were global warming triggered events with the exception of the asteroid impact that
did the dinosaurs in (and 90% of marine life!) 65 million years ago. There have been five
mass extinction events in Earth’s 4.6 billion year history that are well documented in the
fossil record. A mass extinction means that a majority of living organisms went extinct
in a relatively short time. But “short time” is relative to the length of geological time on
Earth, 4.6 billion years. In the geologic past this meant that these extinctions were
occurring over millions of years. Harvard biologist E.O. Wilson and many other
scientists today make the astounding claim that the rate of extinction today is one
thousand times higher than it otherwise would be due to 6.5 billion (and rapidly
increasing) humans on the planet. Could we be experiencing another and much more
rapid mass extinction event on Earth in the present? And if so, could we be the cause?
Well, let’s again consider the fact that the population of clever minded humans has
ballooned to 6.5 billion individuals in an astoundingly short time. If the Earth can only
sustain at most 1 billion humans on extant annual sunlight then it’s clear that something
else has allowed our numbers to grow so large. That something is the buried treasure of
fossil fuels and the fantastic amount of energy it provides us. The majority of the energy
to grow our food, run industry and transportation and to keep our buildings comfortable
and well lit comes from combusting coal, oil, and natural gas. But burning fossil fuels
comes at a high price. All that carbon that went into growing the ancient organisms 300
million years ago that comprise today’s fossil fuels goes back into the atmosphere from
whence it originally came. In fact we know that the Earth’s average temperature has
swung between ice ages and hot house Earths throughout geological history. And with
careful study we have learned that greenhouse gasses, particularly CO2 contribute to
these swings in Earth’s average temperature. Greenhouse gasses have risen and fallen as
life has evolved on Earth contributing to temperature swings by as much as 6 degrees C
or more which can mean the difference between an ice age or an extreme global warming
event. You might not think that a temperature rise that seems so little could change the
environment on Earth for life so radically, but consider how even a little change in your
core body’s temperature is a sign of illness. How does CO2 contribute to global
warming? To begin with CO2 which occurs naturally as the byproduct of respiration of
living organisms exists in relatively small amounts in our atmosphere at present (0.05%)
and it has the chemical property of reradiating back to Earth heat energy from sunlight
that would otherwise reflect back into space. CO2 naturally creates what is called the
greenhouse effect, like heat being retained by glass in a greenhouse, and keeps the planet
from freezing. This is a good thing for warm blooded Homo sapiens and the other
organisms on Earth who depend on mild temperatures. But a little CO2 goes a long way
in regards to trapping heat. Recall that Venus with an atmosphere of 95% CO2 is hot
enough to melt lead. And CO2 lasts for decades in the atmosphere so any that we add by
burning fossil fuels continues trapping heat for many years. The science of climate
change is young but the signs are clear. CO2 has been measured now for decades and
clearly correlates with the rise in average temperature on Earth. It is the added heat that
is changing climate around the planet and in fact much more rapidly than scientists
expected. The Earth will always abide, but it may not be a habitable place for us or the
creatures that are adapted to the present conditions. We have been warned. One fact
about life on Earth cannot be ignored: 99% of all the creatures who have inhabited our
green and blue home planet have eventually gone extinct. And in the great die offs that
have occurred, the first to go are those organisms at the top of the food chain. Will we
heed the warming before it becomes too late to do anything? The root word of sapiens is
sapient which means to be wise, if we never before have been called upon to live up to
the high expectations inherent in our species appellation, now is the time.
Answer the questions below.
1. How many mass extinctions have occurred in Earth’s geologic history?
2. What is a mass extinction?
3. What is the length of time that “natural” mass extinctions occur over?
4. What do many biologists say the rate of extinction is today?
5. What may be the cause of the present possible mass extinction event?
6. How many degrees C change in Earth’s average temperature can lead to an ice age or
a hot house Earth?
7. What is the greenhouse effect? How is it a good thing for the creatures present on
Earth today including Homo sapiens?
8. Why is Venus so hot?
9. Does the rise in CO2 generated by humans from the burning of fossil fuels correlate
with a rise in temperatures on Earth?
10. Is climate change happening slowly or rapidly toady?
11. Do you think humans can stop global warming and climate change? If so how?
12. What is the root word and meaning of the species name, sapiens?