by Richard Jahnke

Professor Emeritus

Skidaway Institute of Oceanography

“Unlike plagues of the dark ages or contemporary diseases we do not yet understand, the modern plague of overpopulation is soluble by means we have discovered and with resources we possess. What is lacking is not sufficient knowledge of the solution but universal consciousness of the gravity of the problem and education of the billions who are its victims.” Martin Luther King, Jr., 1966.

In the midst of the ongoing debate over global climate change (aka: global warming), there is a gigantic ‘elephant in the room’ that no one wants to acknowledge. That figurative pachyderm is human population growth, an issue that may overwhelm any efforts by developed nations to reduce their greenhouse gas emissions.

Dr. Richard Jahnke

Although many may wish to put their heads in the sand and pretend it isn’t happening, the science is quite clear – the earth is warming. On a year-to-year basis, the global average fluctuates, down a little for a year or two and then up a little for another few years. Observed on the short term, the data are very noisy, but when you step back and look at a larger picture, the trend becomes clear. Over the past 130 years, the upticks have surpassed the downticks. Even adjusting for a generous margin of error, the world is nearly a degree-Celsius warmer than it was when Ulysses Grant was president.

Most scientists agree that the increase in greenhouse gases such as carbon dioxide (CO₂), methane and nitrous oxide are significant contributors to the warming trend. By analyzing gas bubbles trapped in Antarctic ice, scientists have been able to paint a picture of the Earth’s atmosphere going back 800,000 years. Until the 19^th century, CO₂ levels fluctuated roughly between 200 and 280 parts per million (ppm). However, over the past 150 years, CO₂ levels have broken out of those limits and shot nearly straight up to approach 400 ppm.

All efforts to reduce greenhouse emissions may be for naught, if we ignore the ‘elephant’, population growth. Even if all rich nations cut back dramatically on their consumption and emission rates and live more simply, it will merely push the breaking point a little further into the future. As developing nations advance, their citizens justifiably strive to become more comfortable, to consume more – more energy and more resources. And there are a lot of citizens out there in developing countries.

Between 2000 and 2050, world population is expected to grow by nearly three billion people. Stabilizing or slowing the rate of greenhouse gas build-up in the atmosphere in the face of this increasing human pressure is a daunting challenge. Indeed, if the emission rate for every person on earth could be reduced by one third, that increase in population would balance the emission reduction, and atmospheric greenhouse gas concentrations would continue to rise at the present rate. Considering that approximately 30 percent of the heat-trapping effects are due to non-CO₂ greenhouse gases like methane and nitrous oxide, which are released mostly through agricultural activities to feed the growing population, and the challenge of stabilizing emissions is even greater.

The most effective method of slowing population growth is education, and particularly the education and emancipation of young women and girls. This is a significant issue in the developing world where much of the future population growth is expected.

One important consideration overlooked by those in developed nations who object to the idea of limits on population is that without a decrease in worldwide population growth, all nations will become overpopulated, as desperate migrants from impoverished, crowded regions seek work in developed nations. More stringent immigration policies won’t stop desperate people.

As the comic strip character, Pogo, famously once said, “We have met the enemy and he is us.”  Ultimately, sustainability of the environment requires population stabilization. Until this is achieved, there is much that can and must be done. Small reductions in population growth provide major benefits and permit future generations more time to recognize their impact and adjust to changing earth conditions. Such achievements require, however, that we open the door for an honest dialog about population – the elephant that future generations need us to acknowledge.