Population growth plays a role in environmental damage and climate change.
But addressing climate change through either reducing or reversing growth in population raises difficult moral questions that most people would prefer to avoid having to answer.
He argued that increases in food production improved human wellbeing only temporarily. The population would respond to greater wellbeing by having more children, increasing population growth and eventually over-running the food supply, leading to famine.
But his essay could not have been timed worse, coming near the beginning of the longest period of sustained global population growth in history. This was driven in part by vast improvements in agricultural productivity over time.
This idea of hard environmental limits to population growth was resurrected in the 20th century in publications such as The Population Bomb, a 1968 book by Stanford biologist Paul Ehrlich, and The Limits to Growth, a 1972 publication commissioned by the Club of Rome think-tank.
The implication of these treatises on the perils of population growth suggest population control is an important measure to limit carbon dioxide (CO₂) emissions and global climate change.
Get The Latest By Email
Four key drivers of global emissions
Population growth is not the only driver of global CO₂ emissions and climate change.
The Kaya identity, an equation introduced by the Japanese energy economist Yoichi Kaya in the 1990s, relates the total emissions of CO₂ to four factors:
- total population
- GDP per person
- energy use per unit of GDP
- CO₂ emissions per unit of energy.
CO₂ emissions can be addressed by reducing any one (or more) of those four factors, provided the other factors are not growing even faster than those reductions.
Not all of the factors are equally easy to affect though. That explains why to date, most countries have concentrated on reducing energy intensity (such as with home insulation to increase the efficiency of energy consumption) and reducing carbon intensity (such as with wind and solar as greener energy production methods).
But the rate of progress in slowing global CO₂ emissions has not been sufficient as yet to achieve agreed targets.
Restricting economic growth
Many people have argued we should target lower economic growth to curb environmental damage.
Globally, the trend is for GDP per person to increase generally over time. Reducing this growth, or moving into managed economic decline, would contribute to reducing CO₂ emissions.
But achieving reductions in CO₂ emissions through reducing economic growth comes with unavoidable distributional consequences, both within and between countries.
Not all countries have shared equally in past economic growth. Low-income countries could persuasively argue it is unfair for their current low level of development to be locked in by reducing their ability to continue to grow their economies.
The moral dilemma of population control
That leaves population control, but the issues here are no less challenging. Government-led population control presents serious moral questions for democratic countries.
That’s why the only country to have undertaken a (moderately) successful form of population control is China, through the One Child Policy that ran from 1979 to 2015. Over that period, the total fertility rate in China roughly halved.
But an unintended consequence of the policy is an accelerated rate of population ageing in China, which now has one of the oldest populations in Asia.
The most challenging aspect of using population control to reduce CO₂ emissions is ethical.
If our concern about climate change arises because we want to ensure a liveable future world for our grandchildren, is it ethical to ensure that pathway is achieved by preventing some grandchildren from ever seeing that world because they are never born?
That is a very difficult question to answer.
Population declines in some countries
Public policy initiatives to control population growth are probably not even necessary.
All high-income countries currently already have below-replacement fertility, with fewer children being born than are necessary to maintain a constant population.
In the year to June 2020, New Zealand experienced its lowest total fertility rate ever, with 1.63 births per woman (replacement fertility needs at least 2.1 births per woman).
Future population growth is projected by the United Nations to peak at around 11 billion in 2100 and then to slip into slow decline after that.
So if we can get through this century without catastrophic environmental effects, then population may start to decline as a contributor to climate change.
Of course, there is a lot of uncertainty about future population growth, so only time will tell whether the UN’s predictions hold true.
There are many ways to tackle climate change, and not all focus on emissions. We could attempt to mitigate its impacts, or adapt to environmental changes, or use technology to remove CO₂ directly from the atmosphere.
On the emissions side, we could look to reduce further the energy intensity or carbon intensity of the economy (the final two factors in the Kaya Identity).
Innovations in any of these areas are likely to be the most fruitful avenues for dealing with climate change, in large part because they avoid the most difficult moral questions.
But if we are unwilling or unable to make those changes work, and soon, then managing population and economic growth may become our only recourse. At that point, humanity will have to confront increasingly difficult moral questions.
About The Author
Michael P. Cameron, Associate Professor in Economics, University of Waikato
Drawdown: The Most Comprehensive Plan Ever Proposed to Reverse Global Warming
by Paul Hawken and Tom Steyer
In the face of widespread fear and apathy, an international coalition of researchers, professionals, and scientists have come together to offer a set of realistic and bold solutions to climate change. One hundred techniques and practices are described here—some are well known; some you may have never heard of. They range from clean energy to educating girls in lower-income countries to land use practices that pull carbon out of the air. The solutions exist, are economically viable, and communities throughout the world are currently enacting them with skill and determination. Available On Amazon
Designing Climate Solutions: A Policy Guide for Low-Carbon Energy
by Hal Harvey, Robbie Orvis, Jeffrey Rissman
With the effects of climate change already upon us, the need to cut global greenhouse gas emissions is nothing less than urgent. It’s a daunting challenge, but the technologies and strategies to meet it exist today. A small set of energy policies, designed and implemented well, can put us on the path to a low carbon future. Energy systems are large and complex, so energy policy must be focused and cost-effective. One-size-fits-all approaches simply won’t get the job done. Policymakers need a clear, comprehensive resource that outlines the energy policies that will have the biggest impact on our climate future, and describes how to design these policies well. Available On Amazon
This Changes Everything: Capitalism vs. The Climate
by Naomi Klein
In This Changes Everything Naomi Klein argues that climate change isn’t just another issue to be neatly filed between taxes and health care. It’s an alarm that calls us to fix an economic system that is already failing us in many ways. Klein meticulously builds the case for how massively reducing our greenhouse emissions is our best chance to simultaneously reduce gaping inequalities, re-imagine our broken democracies, and rebuild our gutted local economies. She exposes the ideological desperation of the climate-change deniers, the messianic delusions of the would-be geoengineers, and the tragic defeatism of too many mainstream green initiatives. And she demonstrates precisely why the market has not—and cannot—fix the climate crisis but will instead make things worse, with ever more extreme and ecologically damaging extraction methods, accompanied by rampant disaster capitalism. Available On Amazon
From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.