by Jenna Dodson
How much of the planet should we leave for other forms of life? How much of the planet can the 7.6 billion present-day human inhabitants utilize without sacrificing the well-being of future generations? These are important questions with far reaching implications for all species, Homo sapiens included. People are placing unprecedented demands on extant species and ecosystem functions through the degradation and conversion of more than half of the terrestrial natural habitat1 and over 85% of the oceans2. Currently, under the international Convention on Biological Diversity, signatory nations are working to protect at least 17% of the terrestrial and inland water, and 10% of coastal and marine areas by 2020. Unfortunately, most scientific estimates suggest that this is not enough to safeguard biodiversity and preserve ecosystems3. In an editorial published in Science, Jonathan Baillie and Ya-Ping Zhang call for total minimum protection targets of 30% by 2030, with an aim to secure 50% by 2050.
In calling for such targets, the authors recognize the need to recognize limits in a finite system. They identify increases in population and consumption as fundamental drivers of natural ecosystem depletion, and explicitly state that human pressures continue to compromise currently protected lands4. However, they neglect to discuss strategies to address these key drivers or reduce human pressure to safeguard more protected areas. It is proving difficult to properly protect land at current levels, and anticipated increases in population and consumption will likely further impede future protection efforts. This unsettling trend reinforces the necessity to include both of these key drivers in discussions of protected areas and species preservation.
A recent review of targets and indicators used under the Convention on Biological Diversity criticized the coverage discrepancy between population and consumption. Consumption was well represented by eight indicators, while population was largely ignored, used in only one indicator. Upon further investigation, this indicator was found to confound population size with various resource consumption metrics, such that population size was not adequately represented. This is typical for the conservation literature, where common indicators such as the ecological footprint or human footprint often only use data measuring the level of human activities, disregarding the underlying factor of growing populations. As a fundamental driver of the biodiversity crisis5 and a key determinant of land conversion, human population size must be incorporated into the biodiversity and protected areas discourse.
This incorporation is particularly important as examination of human population trends shows that of the additional one billion people added to the planet in the last decade, a disproportionate number live in biodiversity hotspots and tropical wilderness areas6. These areas are typically viewed as conservation priorities, and encompass a large proportion of developing nations and vulnerable populations that rely on subsistence agriculture7. The potential complementary relationship between environmental conservation and human socioeconomic development has led to the recent advance of the Population-Health-Environment (PHE) field, which recognizes the linkages among conservation, health, and family planning interventions and strives for natural resources conservation, while simultaneously improving human health and livelihood security7.
Perhaps one of the most successful PHE programs is Blue Ventures, a marine conservation organization located in southwest Madagascar. Through the integration of community-based reproductive health services and marine conservation initiatives, more than 800 unintended pregnancies were averted since 2007, alternative livelihoods developed, and a community-managed marine protected area created8. By identifying the role of population and incorporating effective methods to address it in a participatory social context, program outcomes reduced human pressure, allowing for the creation and effective management of a protected area.
This is not to say that people, countries, or governments located in less biodiverse or low conservation priority areas have no responsibility in this effort. All actors working in this field, including scientists, governments and non-governmental organizations, must first recognize population growth as a fundamental driver of biodiversity and natural habitat loss, and further, incorporate it into strategies and policy actions. These should include increasing education so that fertility becomes a conscious choice, altering economic incentives so large families are not necessary, and providing means to reduce fertility while reducing child mortality—all actions that can be taken at any stage of the economic or demographic transition. By adequately incorporating both consumption and population policy actions, strategies to protect extant species and ecosystem health will likely be more effective. In such a future, calls to protect 50% of the land and the oceans will be more achievable, and the well-being of wildlife and humans preserved.
- Hooke, R., Martín-Duque, J. & Pedraza, J. Land transfomation by humans: A Review. GSA Today 22, 4–10 (2012).
- Jones, K. R. et al. The Location and Protection Status of Earth’s Diminishing Marine Wilderness. Curr. Biol. 28, 1–7 (2018).
- Baillie, J. & Zhang, Y.-P. Space for nature. Science. 361, 1051 (2018).
- Jones, K. R. et al. One-third of global protected land is under intense human pressure. Science (80-. ). 360, 788–791 (2018).
- Crist, E., Mora, C. & Engelman, R. The interaction of human population, food production, and biodiversity protection. Science. 356, 260–264 (2017).
- Williams, J. N. Humans and biodiversity: Population and demographic trends in the hotspots. Popul. Environ. 34, 510–523 (2013).
- Lopez-carr, D. & Ervin, D. Population-Health-Environment (PHE) Synergies? Evidence from USAID-Sponsored Programs in African and Asian Core Conservation Areas. Eur. J. Geogr. 8, 92–108 (2017).
- Robson, L. & Rakotozafy, F. The freedom to choose: integrating community-based reproductive health services with locally led marine conservation initiatives in southwest Madagascar. Madagascar Conserv. Dev. 10, (2015).