Current Population is Three Times the Sustainable Level

Global Footprint Network data shows that humanity uses the equivalent of 1.7 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 half the consumption of the average American - the Earth could sustainably support only about 2 billion people.  

The longer we continue consuming more resources than the Earth can sustainably provide, 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  Eventually they will run dry and hundreds of millions will suffer. Topsoil is being lost 10-40 times faster than it is formed. Feeding all 7+ billion of us will become increasingly difficult.  Oceans are being overfished, and a primary protein source for over 2 billion people is in jeopardy.4  Worldwide, we have lost over half 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?

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 billion people living at a European standard of living may be the upper limit of a sustainable global population.

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.  And climate disruption is likely to create increasing levels of resource conflict and civil unrest.

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 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 September 2017.

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.

3 - David Pimentel. “Soil Erosion: A Food and Environmental Threat”. Environment, Development, and Sustainability (2006) 8:119-137.

4 - “Oceans”. United Nations. Accessed November 2015.

5 - World Wildlife Fund. “Living Planet Report 2016”. Accessed February, 2017.

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.