By one estimate, 24,000 academic journals worldwide publish 1.3 million papers each year.8 A 2015 study by Elsevier, a leading journal publisher, and SciDev.Net, an online science news site, found that the volume of papers related to “sustainability science” was grow-ing by more than 7 percent a year, with an output of 75,602 papers in 2013.9 There was no possibility of reviewing so vast a library of literature. We began our process by developing a conceptual framework de-signed to capture, in simple terms, the two pathways by which we hypothesized that family planning might prove beneficial to the environment.
The resulting framework, refined after a period of external peer review, illustrates two key points:
Peer-reviewed scientific research published since 2005 has rarely considered directly the hypothesis that family planning benefits environmental sustainability. Not surprisingly, given this relative lack of attention, no scientific consensus is apparent in the literature. We cannot confirm the hypothesis. The preponderance of evidence from the papers reviewed nonetheless supports it, with little refutation. Overall, the literature sustains the following statements:
In addition to improving health outcomes for women and their children, access to and use of family planning—specifically effective modern contraception—reduces fertility by preventing unintended pregnancies and timing wanted ones according to partners’ intentions, slowing population growth. This statement is not contested in the literature examined.
The overwhelming majority of researchers who explore relationships between population growth and environmental degradation or resource scarcity either find empirically or assert that the former is an influential factor in the latter, although often interacting in complex ways with other factors. This finding fits well with recent survey work on scientists’ views and some official scientific statements on the influence of population growth on the environment. A handful of papers argue that the role of population is exaggerated or insignificant. Two papers demonstrate cases in which lower fertility under certain circumstances encourages higher per capita consumption, weakening any environmental benefits of family planning.
A Network for Collaborative Assessment
Simultaneously with our search for relevant scientific literature, we worked to build a network of research-assessment collaborators. We invited some individual authors that we encountered in our early scan of research. And we placed a notice in the listserv of the Population-Environment Research Network, based
at Columbia University and read by thousands of researchers around the world. Ultimately, 28 researchers and others working in fields related to our work accepted our invitation, 15 of whom went on to help in assessing research. See “Authors, Project Team, and Research Assessors” on page vi.)
Project staff and consultants began by gathering a few papers that were identified previously through earlier work, and then went on to interview experts for their ideas, to peruse relevant reports for citations, and to explore web-based and library databases. In 2014, we engaged Joe Bish of the Population Media Center, which monitors news from around the world about population and reproductive health, to screen for journal papers meeting our criteria.