Ethicists recognize that limiting population growth is key to addressing climate change

Faced with the reality of global climate change and its devastating impacts, climate ethicists have begun to address the role of population and the need for limits to growth. A new review article reports on this welcome development.

by Philip Cafaro

During the past 30 years of extensive political debate about global climate change, participants have largely ignored the role that curbing population growth could play in dealing with it. On its face, this might seem strange, since our scientific models have long identified population growth as one of the two primary drivers of humanity’s increasing greenhouse gas emissions. The IPCC’s 5^th Assessment Report noted that, “Globally, economic and population growth continue to be the most important drivers of increases in CO₂ emissions from fossil fuel combustion.” According to a recent report from Working Group I for the IPCC’s 6^th Assessment Report, greenhouse gas emissions continue to increase along with global temperatures, and emissions are still driven by growing human populations and increased economic activity.

The mystery deepens when we note that studies have repeatedly shown that limiting population growth is among the cheapest, most effective means to limit and help societies adapt to climate change. And unlike unproven technologies, such as carbon capture and sequestration, or dangerous ones like solar radiation management, modern contraception has been proven safe and effective. Yet during the recent COP26 meetings in Glasgow, little was said about limiting population growth during negotiations, and nothing made its way into the final agreement.

Odd? Yet on reflection, the oddity vanishes, since climate policy discussions are tightly constrained by conventional economic thinking, which regards limits to growth as anathema. Until recently, neither the scientific nor the philosophical communities showed much interest in challenging this taboo. Among policymakers, proposals to limit climate change have focused on technological fixes or efficiency improvements within a context of continued growth.

This longstanding approach, however, has proven itself a failure. Greenhouse gas emissions continue to increase, and disruptive climate change has come on more quickly than expected. Impacts that scientists predicted would show up in the second half of this century are happening now. Worries about how our grandchildren’s lives might be constrained have been replaced by worries about our children’s lives, or even our own.

Addressing population must be part of a global response to climate change

In the face of an obviously unraveling global ecosystem, people are starting to question once-sacred cows, such as the possibility of endless economic growth, or humanity’s ability to safely manage unimaginably complex systems — even if such ideas haven’t yet made their way into national policies or international agreements.

One example of this developing open-mindedness (or perhaps panic) has been a surge in scientific discussions around population in relation to climate change. A 2019 “Warning of a Climate Emergency,” signed by over 11,000 scientists, forthrightly described continued increases in human population and the world gross domestic product as “profoundly troubling signs” of ecological decline. It stated: “The world population must be stabilized — and, ideally, gradually reduced — within a framework that ensures social integrity.” A scientific consensus may be emerging that addressing population must be part of humanity’s response to global climate change.

Thankfully, philosophers and ethicists have also begun to acknowledge the population/climate connection. Ten years ago when I reviewed the climate ethics literature, I found almost no discussion of population matters. But a new follow-up, “Climate ethics and population policy: A review of recent philosophical work,” just published in the journal WIRES: Climate Change, uncovered numerous books and articles exploring the issue. Climate ethicists are now vigorously debating many aspects of population policy, from contraceptive availability to government incentives regarding family size.

Reviewing recent work, I found that both rights-based and consequentialist approaches seek to balance reproductive rights against other human rights and interests threatened by overpopulation and ecological degradation. While biocentric ethicists (those concerned about other species) have additional reasons to advocate for smaller human populations, an important part of the arguments, for humans per se, is to affirm the need to balance reproductive rights against reproductive responsibilities in order to promote the well-being of future generations.

Population needs to be incorporated into climate strategies

Many philosophers now believe, in the words of philosopher Colin Hickey and colleagues, that “climate change is among the most significant moral problems contemporary societies face, in terms of its urgency, global expanse, and the magnitude of its attending harms,” and that “population plays an important role in determining just how bad climate change will be.” While it is possible to put forward plans for mitigating climate change that don’t address population, many agree that such an approach is morally irresponsible since it “falls short of offering a clear and reasonably certain pathway to avoiding dangerous climate change.”

True, making population policy may take us into morally difficult territory. But ignoring population policy is even more problematic, given the high costs of failure to limit climate change. Besides, every nation has population policies, even if they don’t call them that: policies that allow or prohibit couples from choosing the number of children they have, for example, or that incentivize or discourage large families. The real question is whether these policies will be made with reference to justice, sustainability, and the common good.

My recent literature review found that human rights concerns loom large in debates about population policy. On the one hand, opponents of population stabilization efforts often point to past human rights abuses, such as forced sterilizations under India’s emergency decree in the 1970s, to justify their opposition. On the other hand, family planning proponents note that most social pressure and government coercion, now as in the past, involves forcing women to have more children than they want to have, not fewer. Global climate change brings further rights concerns to the table since it directly threatens human rights, particularly the rights to basic physical security and sufficient food, water, and shelter.

One of the most challenging issues in population ethics involves what to do when individuals’ desires for large families lead to environmental degradation. Robust discussion of this issue has been hampered by worries that doing so might stigmatize children from large families, or unjustly blame citizens in poorer countries who have contributed little to climate change. In a crowded world in rapid ecological decline, however, such discussions are needed.

Climate justice beyond “just us”

Beyond human rights concerns, other species arguably have a right to continued existence free from untimely anthropogenic extinction, whether caused by climate change or other impacts of human overpopulation.

Many ethicists emphasize the need to fairly balance human and nonhuman interests, so that human numbers don’t overwhelm and crowd out other species. With the stipulation that justice isn’t about “just us”, affirming a proper balance between human reproductive rights and responsibilities becomes part of sustaining the flourishing of life in all its forms. (Obviously, this concern for the well-being of other species has yet to find its way into actual climate policy choices, as shown most recently at COP26.)

Faced with the reality of global climate change and its devastating impacts, climate ethicists have begun to add their voices to the scientists and environmental activists who support addressing population and facing limits to growth. Across all ethical approaches, there appears to be a strong consensus on the value of choice-enhancing policies that reduce human fertility, such as securing universal access to modern contraception and providing equal rights and opportunities for women. There is also strong support for government policies that incentivize smaller families, considerable support for policies that disincentivize larger ones, and little to no support for punitive policies. Many ethicists warn that failure to enact reasonable population policies now may necessitate harsher or more restrictive policies in the future, a common theme in climate discussions generally.

It appears that anyone who asks ethical questions about population policy in a warming world may find reasonably clear answers. Whether our societies can apply the  answers, and create realistic and effective climate policies, is a further question.