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A Review of “Global warming policy: Is population left out in the cold?”

Aug 21, 2018
A research publication with the title "Global warming policy: Is population left out in the cold?"

Population stalwart John Bongaarts, and the highly accomplished Brian C. O’Neill, recently teamed up to demonstrate why climate activists and policy makers should incorporate population-related interventions into their efforts. Their 2500 word essay appears in the influential Science Magazine – it is cogent, easy to read, and persuasive. We hope it makes an impression.

The authors begin their work by asking an important, albeit rhetorical, question:“Would slowing human population growth lessen future impacts of anthropogenic climate change?” With an additional 3.6 billion people expected by 2100, which would bring us to a total of 11.2 billion, it is no surprise that the answer is a resounding YES.

However, though the Intergovernmental Panel on Climate Change (IPCC) understands that population and climate change influence each other, they have yet to present any recommendations for policy interventions  such as voluntary family planning information and services and improved education for women and girls  that could serve as contributors to climate adaptation and mitigation.

Bongaarts and O’Neill address four misperceptions they believe confound the IPCC (and many other people in the climate change community) on the population issue:

MISPERCEPTION 1: Population growth is no longer a problem

The authors’ attribute this misconception to several factors. These include 1) a now-discredited belief, prevalent mostly in the latter years of the 20th century, that fertility declines in Africa would manifest in similar scope and timelines as occurred in Asia; 2) the impact of the 1994 International Conference on Population and Development (ICPD) championing reproductive health and rights, but effectively creating social stigma around expressing demographic concerns; and, 3) “the failure of earlier dire predictions,” such as worldwide famine, to materialize.

MISPERCEPTION 2: Population policies are not effective

Noting that there are 85 million unintended pregnancies and 32 million unplanned births each year, O’Neill and Bongaarts point out the obvious: avoiding unplanned pregnancies alone would reduce population growth substantially. But, while the near-term effects of programs that increase contraceptive use and reduce birth rates are well-understood, very few studies estimate impacts of family planning programs on longer-term demographic trends. The implication is that this creates a data vacuum, a lack of case-history, and sparse casual evidence  making it relatively difficult to empirically justify interventions. However, the good news is that family planning programs implemented recently in Ethiopia, Malawi, and Rwanda have already “resulted in sharp declines in fertility.” The authors rightly conclude that family planning programs are exceptionally cost-effective investments for governments pursuing health and development goals. 

MISPERCEPTION 3: Population does not matter much for climate

Past and current emissions are attributable primarily to economic growth (powered by fossil fuels) in developed countries, explain the authors. They also remind us of the incontrovertible truth that, heretofore, the high-income countries are almost totally responsible for carbon emissions. However, new research and sophisticated modelling demonstrate “that population plays an important role both in historical and projected future emissions.” For example, industrialization and ongoing rapid population growth in developing countries mean increases in emissions from these sources are almost guaranteed over the next few decades. Bongaarts and O’Neill do well to emphasize that slower and smaller population growth moving forward would not be the most important means of reducing future emissions, but “it could reduce global emissions by 40% or more in the long term.” Clearly, population does matter for climate.

MISPERCEPTION 4: Population policy is too controversial to succeed.

By now, everybody knows that taking a sensible, holistic look at human population and its related sub-issues  and advocating for human rights enhancing interventions such as voluntary family planning and improved education  is controversial. It shouldn’t be, but we all know that it is. Bongaarts and O’Neill first describe traditional opposition from conservative religious and social groups. Importantly, they also note opposition from some liberals and human rights advocates who fear that publicly admitting that population is a climate variable, open to wise, carefully administered interventions (like family planning and girls education) will automatically lead to coercion and human rights abuses. In fact, it was only a matter of hours before The New Scientist published an essay expressing these exact concerns about Bongaarts’ and O’Neill’s position.

The two authors also revisit the fact that the countries with the greatest need for family planning programs are in the developing world  while the developed world, which generally already has strong family planning services, continue their self-indulgent, reckless greenhouse gas emissions:

“Many in the climate change community believe that entering into a population policy discussion thus blames the poor countries for problems created by the rich countries. Although this belief is real, it does not change the fact that population growth in developing countries poses challenges for climate and development and deprives the international community of an important policy lever to improve human welfare.”


The authors end their good work by advocating for the IPCC to include population-related policy recommendations for mitigation and/or adaptation in their future publications – including cost and benefit accounting, barriers to implementation, and synergy with SDG goals and targets. They also wisely call for including more social scientists experienced in reproductive health and population policy to be included on the IPCC. Finally, the authors urge the environmental community and international development institutions “to embrace scientifically sound analyses of population policy and human rights–based reproductive health programs.”

Hats off to Mr. Bongaarts and Mr. O’Neill for this persuasive and well-received effort.