Climate change, to use a bad pun, is the hottest environmental issue of our time. However, is focusing on the increase of CO2 in the atmosphere distracting us from bigger underlying issues?

For me the first law of science has always been, “There ain’t no such thing as a free lunch.” You can’t exist without impacting the environment around you. Every step you take, every breath you take, every move you make changes something. Nothing has zero impact, and even the smallest impact, repeated a sufficiently large number of times, can be damaging.
In national parks, we have long been taught, “Take only pictures; leave only footprints.”

However, multiple footprints have an impact on the environment. One creature taking a route leaves only footprints. Footprints from humans or animals that repeatedly follow the same route create a path. In my garden there are trails from voles, little creatures that typically weigh less than 4 ounces. Sometimes when I’ve hiked, I have gone the wrong way because I’ve mistakenly turned off onto a cow or deer trail. In parks, to keep the footprint damage to a minimum and confine that damage to a limited area, we are cautioned to stay on the trail. But as anyone who has taken a popular trail knows, too many people will cause the trail and the adjacent area to erode.

Even stone will erode with too many human footprints. Think of the deeply incised steps of old cathedrals. If stones selected for their durability as building materials cannot withstand repeated footsteps, how can the rest of the environment avoid damage from an ever-growing human population?

In 1798, using extrapolations of population growth and food production growth trends, Thomas Malthus predicted that the rising population would result in food shortages in about 50 years. He reached his conclusion just before the use of fossil fuels (predominantly coal) rapidly increased with the industrial revolution and human population soared. In 1800 the global population was about 1 billion. It is now about 6.4 billion.

For more than 200 years mankind has been able to not only refute Malthus’ prediction of famine but to enable people to enjoy higher standards of living by harnessing the power of fossil fuels, science and technology. Have we hit the limits of the ability of human ingenuity to scavenge energy from the world around us to support more of our species in comfort? Can we continue to avoid the Malthusian catastrophe of over-population? Is rising atmospheric CO2 the greatest threat we face, or just one symptom of the growing human load on the planet?

Can we draw analogies between the environmental consequences of the rapid increase in human population from the fate of algal blooms? In an algal bloom, increased concentrations of nutrients enable a rapid proliferation of algae. The density of algae may quickly increase by factors of 100 or more. Algal blooms kill other aquatic life by decreasing the amount of sunlight that can penetrate the water, by using the available oxygen dissolved in the water and by producing harmful toxins. After relatively briefly dominating the environment, the algal bloom vanishes.

In effect, we humans have increased our concentrations of nutrients by harnessing the power of fossil fuels. With fossil fuels and technology, we surpassed Malthus’s food production trends and enabled mankind to produce an abundance of food. This has allowed the explosive population growth of the last 200 years.

With the current “homo sapiens bloom,” we are driving other species to extinction. At a smaller population density, our waste products would not be a problem. Think of the sewage treatment that is necessary just to keep us from poisoning ourselves with our bodily wastes. Clean fresh water is as precious a commodity as energy.

Climate change focuses on a single impact of human technology. Any energy alternatives we develop will also change the environment. Harnessing renewable energy is not without environmental impacts. A ray of sunlight or a drop of water that is deflected from its original destination changes something.

There is no magic energy solution that has no environmental impact. We are looking at a minimization problem in which the goal is to provide the most energy with the least environmental impact. Key complications are that we don’t know the full environmental impact of current technology, let alone emerging technology. Moreover, we don’t agree on the relative priorities as to the mitigation of known impacts.

Energy efficiency holds the allure that we can harness for productive purposes more of the energy we use. In the United States about 58% of the energy we use is lost. Even with regard to energy efficiency, “no such thing as a free lunch” still holds. The manufacture of energy efficiency equipment will have an environmental impact and cost.

Let’s return to the algal bloom analogy. The Netherlands Institute for Sea Research (http://www.sciencedaily.com/releases/2002/11/021118065830.htm) reports that even though algae are resistant to viruses during the period of rapid growth, algae weaken once the supply of nutrients has been depleted. Viruses can then destroy the algal bloom within days.
Is global warming the biggest threat to mankind? Should we be more concerned about a global pandemic? Will

we weaken our species and succumb to one or more viruses, such as influenza
or ebola? Will the now dominant species, homo sapiens, be brought down by a lowly bacterium like Mycobacterium tuberculosis, Staphylococcus or Streptococcus? Or will science and technology again triumph as they did following Malthus’s prediction by devising ways to harness new energy sources that have a smaller impact on our environment?

Human ingenuity is our greatest asset. It is exciting times for those of us in the industry as we again seek to defy Malthusian predictions. We must ask the right questions as we seek solutions.