You won’t hear about it from green campaigners, but many of the key drivers of environmental destruction are slowing down.
How to Achieve Peak Environmental Impact by Linus Blomqvist, Ted Nordhaus and Michael Shellenberger
(This post was written for Mark Lynas, who is co-hosting an event with us on ecomodernism at “Sense About Science” in London next Thursday evening.)
The rate of population growth is nearly half today what it was in 1970. The global population could peak as early as the middle of this century. By some calculations, the amount of farmland needed to grow food globally has already peaked. Meanwhile, per capita water use, food consumption, and material use have all already peaked in rich countries, and many developing ones as well.
Taken together, these trends suggest a truly remarkable possibility: overall, negative human impacts on the environment could peak and then decline within the next several decades.
How soon we hit the peak, and how rapidly impacts decline, depends on how quickly key trends driving the slowing of environmental impacts can be accelerated. And therein lies the rub for environmentalists: to get to peak environmental impact quickly, we will need to accelerate key economic and technological processes that greens have long opposed.
Consider population. The primary determinant of whether global population peaks around 2050 at 9 billion people or 2100 at 11 billion will be how quickly sub-saharan Africa develops. The faster Africa moves its population out of the subsistence agrarian economy and into cities, the faster population will stabilize. That’s because in the agrarian economy, children are needed to work the fields and support aging parents in circumstances in which there is no social safety net to speak of.
When families move to the city, fertility rates fall from as many as 5 or 6 to 2 or fewer. Women gain economic opportunities outside the household. Children are valued for their future earning potential in the formal economy, rather than their labor in the fields.
Rapid urbanization requires jobs in the city for those who migrate and higher agricultural productivity for those who continue to farm. This requires industrialization and agricultural modernization. A growing manufacturing base has long been a crucial way to integrate a large, low skilled population into the formal economy, and increase labor productivity. To grow more food on less land, farming becomes mechanized, relieving agricultural workers of a lifetime of hard physical labor.
Urbanization and industrialization are hard pills to swallow for environmentalists who have long valorized peasant farmers, demonized industrial agriculture, and railed against the evils of consumption and capitalism. But the evidence is clear that when people move to cities and farm more intensively, birth rates fall, per capita land use for food production declines, and pressures on forests, ecosystems, and biodiversity are reduced.
The one driver of global environmental impacts that doesn’t slow when populations urbanize and economies modernize is energy consumption. But here again, accommodating the development imperatives of a global population that remains overwhelmingly poor — while mitigating the environmental consequences of energy consumption — forces the green movement to reconsider some long held shibboleths.
The United Nations Sustainable Energy for All initiative, for instance, is predicated on the notion that much of the global population stays poor and rural, consuming a tiny fraction of the energy that citizens of developed economies take for granted. Even were developing world populations willing to accept this future, which they most assuredly do not, the consequences would not bode well for the environment.
Large rural populations dependent on subsistence agriculture are hard on the land and hard on nature. They clear forests to make room for low productivity farming and pasture, hunt bushmeat for protein, and depend on fuelwood and charcoal for cooking and heating.
A cheap solar panel on a thatched roof hut powering an LED lightbulb and a cell phone charger can shine a light on rural poverty but can’t help large populations escape it. That requires far larger amounts of energy to power irrigation and tractors on the farm and factories in the cities. It requires roads and other infrastructure to provide farmers with access to markets and urban populations with access to commercially grown food.
Emerging economies, from Great Britain onwards, have historically met this need with large hydro-electric dams and fossil energy, which provides large quantities of cheap, on demand grid electricity to growing urban populations, industrial facilities, and large scale agricultural operations.
All energy production comes with tradeoffs. Dams harm local river ecosystems, but they also provide water for irrigation and power for farmers, allowing higher agricultural productivity and less clearing of forests for fuel and food. Fossil fuels emit carbon into the atmosphere and pollute the air but replace wood and charcoal for heating and cooking, which result in millions of indoor air pollution deaths annually.
While the environmental consequences of continuing growth in energy consumption can’t be eliminated, they can be significantly mitigated. Sub-saharan Africa has enormous hydro-electric potential and is rich in natural gas. It is possible, indeed even likely, that rapid urbanization and development in Africa might be powered by gas and hydro instead of coal.
Many poor and emerging economies are also increasingly turning to nuclear energy. China and India have both launched ambitious programs to build large fleets of conventional plants and develop a new generation of advanced nuclear technologies that are cheaper and burn their own waste. Kenya and other poor nations have launched joint ventures with China, Slovakia and South Korea to construct nuclear plants domestically.
Nuclear power is hands-down the best source of energy for the environment, producing large quantities of reliable zero-pollution power on a tiny patch of land while the tiny quantity of radioactive waste nuclear produces is easily and safely stored.
The environmental benefits of accelerating urbanization, agricultural productivity, and decarbonization are enormous. With far higher yields on larger farms, marginal farmlands revert back to grasslands and forest. Urbanization, agricultural modernization, and rising incomes from industrialization take pressure off of parks and protected areas in poor countries.
Thanks to those factors, forests are coming back across much of the United States and Europe and many developing nations like Costa Rica have been able to protect much more of their forests and biodiversity in parks and protected areas.
Today, humans use about half the Earth to meet our material needs, most of that for food production. With accelerated urbanization, agricultural productivity, and decarbonization, it is possible that we could very significantly shrink human impacts over the course of the next century, leaving 70 or even 80 percent of the Earth to nature.
That future is by no means automatic. Accelerating the diffusion of better and cleaner agriculture and energy technologies is a program that governments and global institutions ought to be able to get behind, as they once did for the green revolution in agriculture.
To realize the our full potential to shrink the human footprint and bring back more nature, we’ll need better technologies still. We’ll need next generation nuclear plants that can’t meltdown and burn their own waste; seeds that produce their own pesticides and better tolerate drought on a hotter planet; water recycling and desalination; aquaculture that spares wild fish populations; and ways of producing meat requiring far less land and resources.
Peak human impact is an inspiring vision, and it is within sight. Achieving it will be difficult, but no technological or scientific breakthroughs nor significant economic sacrifices are required. Human societies have repeatedly shown themselves capable of overcoming outmoded dogmas and myths — not just with science and rationality, but also with positive visions of the future. We can do that again.