Global Footprint Network data shows that humanity uses the equivalent of 1.75 planet Earths to provide the renewable resources we use and absorb our waste.1 If all 7+ billion of us were to enjoy a European standard of living - which is about 60% the consumption of the average American - the Earth could sustainably support only about 2 to 3 billion people.

It is important to note that the depletion of non-renewable resources such as fossil fuels, metals, and minerals that make a higher standard of living possible are not included in Global Footprint Network data. This includes all the tons of oil, coal, iron ore, copper, and hundreds of other minerals and metals that make modern life possible. Taking these non-renewable resources into account suggests 2 to 3 billion people living at a European standard of living may be the upper limit of a sustainable global population.The longer we continue consuming more resources than the Earth can sustainably provide and producing more wastes than it can absorb, the less able the Earth can meet humanity's resource needs in the future. And the fewer people the planet can support - long-term.

Evidence of unsustainable resource use is all around us. Global aquifers are being pumped 3.5 times faster than rainfall can naturally recharge them.2 As they run dry hundreds of millions will suffer. Topsoil is being lost 10-40 times faster than it is formed.3 Feeding all 7+ billion of us will become increasingly difficult. Oceans are overfished, and a primary protein source for over 2 billion people is in jeopardy.4 Worldwide, we have lost 60% of the vertebrate species in the air, water, and land since 1970.5 How many more species can we lose and how many more ecosystems can we destroy before humanity’s own existence is threatened?

Climate change will only add to the strain on the planet’s ability to support all 7+ billion of us. Climate scientists are warning us to expect lower crop yields of major grains such as wheat, rice, and maize.6 Rising sea levels could create hundreds of millions of climate refugees.7 And climate disruption is likely to create increasing levels of resource conflict and civil unrest.8

Adaptation to climate disruption will be much easier with a much smaller global population. We can achieve a smaller global population tomorrow by beginning a dramatic, voluntary reduction in births today.

All of us want a viable, sustainable global home. If we allow overpopulation and overconsumption to continue, the evidence is mounting that billions will suffer and that we will leave future generations a much harder, bleaker life.

Reducing birth rates now can save us from the likely increase in death rates that awaits us if we do nothing. Solving overpopulation is essential in building a sustainable future.

1 - “World Footprint”. Global Footprint Network. Accessed January 2020. footprintnetwork.org/en/index.php/GFN/page/world_footprint/.

2 - Tom Gleeson, Yoshihide Wada, Marc F.P. Bierkens, Ludovicus P.H. van Beek. “Water balance of global aquifers revealed by groundwater footprint”. Nature 488, (2012): 197-200. Accessed October, 2015. nature.com/nature/journal/v488/n7410/full/nature11295.html.

3 - David Pimentel. “Soil Erosion: A Food and Environmental Threat”. Environment, Development, and Sustainability (2006) 8:119-137. saveoursoils.com/userfiles/downloads/1368007451-Soil%20Erosion-David%20Pimentel.pd

4 - “Oceans”. United Nations. Accessed November 2015. un.org/en/sustainablefuture/oceans.asp

5 - World Wildlife Fund. “Living Planet Report 2018”. Accessed December 2018. wwf.panda.org/about_our_earth/all_publications/living_planet_report/.

6 - A.J. Challinor, J. Watson, D.B. Lobell, S.M. Howden, D.R. Smith, N. Chhetri. “A meta-analysis of crop yield under climate change and adaptation”. Nature Climate Change 4, (2014): 287-291.

7 - Charles Geisler and Ben Currens. "Impediments to inland resettlement under conditions of accelerated sea level rise". Land Use Policy vol. 66, July 2017: 322-330.

8 - Caitlin E. Werrell and Francesco Femia, editors. Epicenters of Climate and Security: The New Geostrategic Landscape of the Anthropocene. climateandsecurity.files.wordpress.com/2017/06/epicenters-of-climate-and-security_the-new-geostrategic-landscape-of-the-anthropocene_2017_06_091.pdf