Population Matters

Humanity’s gamble by Paul & Anne Ehrlich

Humanity’s gamble by Paul & Anne Ehrlich

This past February 13th to the 17th in Chicago, the world’s largest general scientific conference was held — the American Association for the Advancement of Science (AAAS) Annual Meeting. Paul Ehrlich was on the bill for a Food Security and Sustainability discussion, along with two NOAA researchers and Jonathan Foley of the University of Minnesota. Immediately below is the core of Dr. Ehrlich’s presentation, which he co-authored with Anne Ehrlich.

Humanity’s gamble

Paul R. Ehrlich and Anne H. Ehrlich

Humanity is taking a gigantic gamble in assuming it can feed and support as many as 9.7 billion people in 2050, a third more than exist today, without revolutionary changes in behavior. The world community is betting that climate disruption will not prevent continuing increases in yields of grains and soybeans and, combined with ocean acidification, not reduce fisheries productivity. It is betting that, in the face of climate disruption, changes in infrastructure and other measures will prevent further deterioration of water security, especially in critical access to water for irrigation. It is betting that the food system, heavily dependent on oil and itself producer of roughly a quarter of global greenhouse gas emissions, can make a substantial start on kicking both habits. It is betting that the need for more food will not prevent society from undertaking a serious commitment towards global atmospheric decarbonization. It is betting that the energy-intensive and highly polluting Haber-Bosch process can continue to keep nitrogen levels in agricultural systems adequate and to a large degree replace sound soil husbandry, even while reducing the deleterious effects of overfertilization runoff on ocean and freshwater productivity. It is betting that the geopolitical problems surrounding the world’s available supplies of phosphorous for fertilizer, especially battles over Western Sahara, will be solved. It is betting that integrated pest management can safely and effectively replace both the pest-control service of winter in midlatitudes as the global annual temperature rises, and the pest-control services of birds, bats, and predacious insects as their populations decline in the great sixth extinction episode now well under way.

That’s far from the last of the bets. Humanity is also betting that, especially for the variety and nutritional quality of food, pollination services will be maintained despite the biodiversity crisis. It is betting that the ‘genetic insurance’ provided by the wild relatives and indigenous cultivars of food crops will not be eroded or eliminated from the countryside and remaining wildlands by the drivers of global environmental change operating in synergy. It is betting that the growing demand for meat and bio-fuels will not greatly reduce the access of the poor to grains. And perhaps most important, it is betting that people will find the jobs that will provide the income to purchase what food is available.

At the moment this looks like a very bad series of bets, especially since close to a billion people are already hungry and more than that are malnourished. Losing several of the bets could easily result in many deaths and great hardship, or even in some combination of mass starvation, epidemics, and warfare (possibly nuclear), leading to a general breakdown.

The odds of avoiding a collapse could be improved if society launched a coordinated effort to stop expanding land under agriculture (to preserve natural ecosystem services); increase yields where possible; revise the industrial agriculture system to make it more ecologically sound, place much more emphasis on soil conservation and increase the efficiency of fertilizer, water and energy use; become more vegetarian; reduce food wastage; stop overfishing and changing the chemistry of the oceans; greatly enlarge investment in, and dramatically change the direction of, agricultural research and development; educate all about how the human food system works, and move proper nutrition for all to the top of the global policy agenda. It is a large order.

Scientists, in analyzing the prospects for supplying an exploding human population with adequate diets, must point out that the citizens of developed nations should stop at an absolute maximum of two children per couple and work to curb their consumption. They must abandon the impossible goal of perpetual economic growth through increasing consumption. For any scientist not to emphasize these points wherever possible borders on the unethical.

The situation in developing nations, especially in sub-Saharan Africa where population is still growing at 2.7 percent annually, is more complex. It certainly includes a great need for dramatically restraining reproduction in most circumstances, a major exception being in rural areas where infant mortality remains high and where having more than two children is often an economic necessity.

In summary, the human predicament is unlikely to be solved unless the scale of the human enterprise – global population size and per capita consumption among the rich – can be reduced as rapidly as humanely possible.

All is not hopeless. Demographic shrinkage is approaching in many overconsuming rich nations, where it is most important. There is substantial room for improvement in crop yields in Africa, for building rural health clinics there, and for making modern contraception and backup abortion universally available, three areas where aid from the developed world could be invaluable. Giving women equal rights everywhere would constitute a good start on reducing fertility rates and improving humanity’s odds of avoiding catastrophe. It would be a lot easier to nourish 8.5 billion people adequately in 2050 than 9.7 billion.


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