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Americans began to take environmental issues seriously in 1969 when the Cuyahoga River in my hometown of Cleveland caught on fire. On grade-school field trips to the Cuyahoga, I remember seeing pipes carrying brightly-colored effluents entering the river. The water pollution of the Cuyahoga typified the problem of “point-source” pollution that was rampant throughout the nation. Corporations, municipalities, even individuals regarded our air and water as the logical dumping ground for myriad wastes of a modern industrial society—“the solution to pollution was dilution.”
With point-source pollution, blame was easily cast, appropriate remedial actions were obvious, and the regimen for cure, perhaps painful to initiate, was effective. Some sources of pollution were local while others, such as the sulfur dioxide emitted from coal-fired power plants, cast acidic deposition over a vast downwind region. In college I measured a pH of 3.4 in the rainfall on Mt. Moosilauke in New Hampshire.
The Clean Air Act, the Clean Water Act, and the Endangered Species Act appeared with bipartisan support shortly after Earth Day in 1970. While toxic legacies of point-source pollution persist, such as the PCBs that General Electric dumped into the Hudson River, we have much reason to rejoice from the early successes of the environmental movement. Few pollutants now spill unregulated into the natural environment, urban children have lower levels of lead in their blood, and whitefish have returned to Lake Erie. Still, the age-adjusted breast cancer rate among women born after 1940 vastly exceeds that of earlier generations—a poignant reminder of the toxics we’ve added to today’s environment and that there is not always “better living through chemistry”.
Twenty years after Earth Day, the critical environmental problems are even more complex challenges than in the early 1970s. Today’s environmental problems stem from a rising global population of humans, now close to seven billion, each with a desire for a higher standard of living. Last year the world’s population increased by 75 million, equivalent to adding a new Raleigh-Durham metropolitan area every two weeks. While the growth rate of population has slowed since the 1960s, global population has doubled since the first Earth Day, and it continues to grow exponentially. Meanwhile, our planet, save for the receipt of a few meteors, doesn’t grow at all. There are ample field and laboratory studies that show the collapse of populations growing exponentially in a finite environment. Why should Homo sapiens be different?
Nighttime satellite photographs show that humans now occupy nearly all of the Earth’s land surface that is not too dry or too cold for our physiology. The rising human numbers leave less of nature in its natural state, fewer species to share the planet with us, and changes in the basic chemistry of Earth’s atmosphere and oceans that form the evolutionary environment for all life now on Earth. The old challenges of abating point-source pollution now seem simple compared to how we must address the global impact of humans on the chemistry, climate and biodiversity of our planet.
Strip away the sapiens and the rising numbers of humans show singular Darwinian motivation to pursue resources to make life comfortable. For the past couple of centuries, we have capitalized on the use of fossil fuels to supplant human labor, heat and light our dwellings, grow our food, and move us about in pursuit of the good life. Population growth rates decline with increasing per capita energy use, but the rate of decline is too slow to circumvent greater overall energy use by the human population. The correlation between the growth of carbon dioxide in Earth’s atmosphere and our rising population shows an astounding r = 0.9986. And one recent study reports a new trend of increasing fertility in families at the highest levels of economic well being.
Sixty-five percent of the rise in CO2 concentration in the atmosphere is attributed to increasing global economic activity. Increasingly, we seem willing to sacrifice areas that are dear to us, such as the Outer Banks of the Carolinas, in the pursuit of the last drop of petroleum that we can extract from the Earth’s crust. Bigger is better, when it comes to pick-up trucks, suburban houses, and McDonald’s hamburgers. Apparently, these are the measures of our evolutionary fitness in the modern world.
In the face of rising human population, most of our food production is dependent upon external subsidies of fossil fuels, especially petroleum, for which there is no obvious alternative at a reasonable price to feed us all. Without exogenous nitrogen fertilizer made with fossil fuels, it is doubtful that the present global human population could feed itself adequately. Meanwhile, freshwaters, especially groundwater, are widely depleted and contaminated with nitrogen from fertilizer runoff. There is nothing sustainable about feeding a population with exponential growth in a finite environment.
Humans are already pushing the biophysical limits of the Earth, changing its climate, ocean circulation, stratospheric chemistry, and net primary productivity—all of which sustain life on our only planetary home. In the geologic record, we see major extinction events that have accompanied similar changes in these planetary properties in the past. The predicted changes in climate alone are destined to impact the food supply for our increasing population. Given recent events, it seems doubtful that we will withstand lower per capita resource availability on a crowded planet without famine, war and epidemics. I suspect that the human species will survive, but at what quality of life?
Even so, economists applaud rising human population and tell us that economic growth of about 4% per year is best for human well-being. The Wall Street Journal’s front page carries a story “Population’s flagging growth undermines global economy.” Don’t worry, we are told, we will grow the size of the resource pie. Demand in the face of shortage yields rising prices which bring new supplies to market. Economists say that if critical resources fall short, we will simply substitute other goods. The threat of lost jobs and lower profits trumps nearly all efforts to protect the environment from excessive exploitation. But mention family-planning policies to political leaders, and they scamper to escape the room.
So, the biggest challenge facing those concerned about the environment will be to change the thought process of the public to the notion that a steady-state economy is the best alternative for the future. The job will not be easy. Sustainability will not be achieved with rising human population and increasing resource use. The challenge asks for a change in human nature, so that we can live up to the species epithet of sapiens and behave, not like the squirrels at my birdfeeder, but it a manner that is truly best for the biosphere with all its inhabitants.
This essay first appeared in dukenvironment magazine (Duke’s School of the Environment) spring 2016