When the demand for, and the consumption of, a stock limited
(exhaustible) resource steadily rises, the price is driven up until the
resource is “economically depleted” which means the cost of producing the
resource is higher than the value of the product. At that point a substitute (or alternative) resource becomes
cost-effective.
The
exhaustible energy resources heavily relied upon now are fossil fuels (coal,
oil, and natural gas) and, to a lesser extent, nuclear resources. Exhaustible energy powers the economy of the
United States and the lifestyles of its people. More than 85% of U.S.
commercial energy is derived from fossil fuels, and 8% from nuclear. Only 7% of
our commercial energy is provided by renewables, mostly as biomass and hydropower[1],
and increasingly wind and solar.
Let’s focus on the most problematic fossil fuel—petroleum. Currant
estimates of readily accessible reserves suggest we have about 30 years of oil
left as long as every country in the world maintains current consumption
patterns, i.e. consumption will not increase. We are at or very near the peak
of the global oil consumption graph, a spike-like representation of the
historic (actual) and future (projected) consumptions of world oil reserves. We
have consumed about half of the estimated 1.8 trillion barrels believed to be
available
[2].
This means that consumption from here on is on the downhill side of the
“petroleum consumption curve.”
That’s supply. What about demand? Today there are 6.7
billion people on earth. Our population is increasing by about 1.2% per year,
and this apparently low rate is slowly decreasing. Even with the low and decreasing
rate, this is an increase of 78 million in the human population per year. That
is an increase of 213,000 people per day, or more than one million people every
five days. The United Nations estimates that the mid-century human population
will be 9.2 billion people
[3].
With the addition of 2.5 billion people, it is very likely that world petroleum
consumption patterns will increase.
At present, a disproportionately small share of the people of the
world uses a disproportionately large share of the world’s energy
resources. Eighteen percent of the
world’s population lives in the forty or so developed countries. The other 82%
of humanity lives in 160 countries that are economically classified as less-developed
[4]. More developed countries have population
growth rates near, or even below, zero percent annually (zero to negative
population growth). People in the
developed countries typically use about four times the resources (energy and
otherwise) and generate about four times the industrial pollution than people
in less developed or developing countries.
Because the largest population growth occurs in developing
countries, demographers suggest less-developed countries must become developed
countries for the human population to stabilize. If the 5.2 billion people in the developing countries increased
their resource use four fold to meet the consumption level of the developed
countries, this would further increase the demand of world petroleum resources.
Even without the addition of 2.5 billion people, the end of the recoverable oil
may be much sooner than 30 years away.
Reliance on stock-limited resources generates other problems
aside from their exhaustibility. One is pollution—pollution from fossil fuels
(air pollutants) and pollution from nuclear fuels (radioactive wastes). We
have, with varying degrees of success, addressed or accepted some aspects of
the pollution generated by our energy choices—soot, sulfur dioxide, smoke, etc.
We have not dealt very well with the more dangerous effects of radioactive
waste from nuclear power generation and the carbon emissions from burning coal,
oil, and natural gas. This latter pollution is liberated when carbon fuels are
oxidized (burned). Carbon dioxide is one of several “greenhouse gases”
(heat-trapping gas) that actually makes the world livable; without them, Earth
would be a frozen planet.
However, today’s rapidly rising amounts of carbon dioxide
are a problem—they warm the planet too rapidly. The immediate challenge facing
humanity on Earth is not the extent of the predicted change, but the very rapid
rate of the change. Climatologists estimate that the current human-caused
warming is 50 times faster than the relatively rapid warming that occurred
10,000 years ago with the retreat of the latest glaciation of the Pleistocene
Epoch
[5].
Life is moderately resilient to moderate environmental
change, but it is much less resilient to rapid change—higher life forms that
have generation times measured in weeks, months, and years, and that depend on
relatively stable environmental conditions, are most at risk. [Microbes, with
generation times measured in minutes, hours, and days, are much more robust.]
Large vertebrates, including humans, will be subject to the greatest disruption
as critical ecological entities such as forests, croplands, coral reefs, etc.
find themselves stranded in the wrong climate. Polar bears in the wild are one example;
increased temperatures have limited their habitat. Little can be done at this
point to improve their situation.
Thus, fossil fuels are troublesome for two
reasons—decreasing supplies and unacceptable environmental risk. Either issue
is serious enough to initiate immediate action. Some call for increased
contributions of nuclear, biomass (ethanol and biodiesel), wind, hydro, geothermal,
tidal, and solar energy to reduce dependence on fossil fuels.
Is it the better part of wisdom not to choose nuclear power,
since it is inherently dangerous (high temperature, high pressure, and high
toxicity), and fissionable uranium is another exhaustible resource with
pollution problems of its own. Solar energy and solar-derived energy resources
(e.g. wind and flowing water) seem to offer better, long-term choices. These
resources are flow-limited—the other side of the energy-choice coin. Flow-limited
resources are perpetual resources
– they flow as long as the sun
shines) – a definite advantage for anyone who believes in tomorrow. They are,
as the term implies, limited in the sense that they can be used faster than
they flow. Until recently, the whole Earth-life enterprise operated on
perpetual solar energy—and the flow was fast enough to give us grizzly bears, starfish
and competent humans.
Whether the reason is pollution impact or resource
exhaustion, humans must reduce their consumption of energy for irrational,
trivial, and destructive purposes. Reduction is necessary at the community
level and the individual level. On the
community level, it would take a wise and confident person to propose an energy
plan that would reduce the amount of energy use to the capacity of the
environment to deal with it and reserve energy use for constructive purposes.
On the individual level, to reduce overall personal (and
collective) energy would involve fundamental shifts in the way that Americans
view their lives, their work, and their play. It would involve citizens
assuming a sense of responsibility with respect to each other (including the
other 94 percent of humanity) and to the ecological systems that support life. Changing the way we live can be overwhelming
but incremental changes can make a difference.
When we were few and far between and when our tools were
rocks and sticks, and when our energy was muscle and campfire, our decisions
and their effects rippled a few hundred feet around us. Now that we are very,
very many and our tools are very, very powerful, our decisions and their
effects rumble across the face of the Earth.
