Current Population is Three Times the Sustainable Level

Current global population of over 7 billion is already two to three times higher than the sustainable level. Several recent studies show that Earth’s resources are enough to sustain only about 2 billion people at a European standard of living.

An average European consumes far more resources than any of the poorest two billion people in the world. However, Europeans use only about half the resources of Americans, on average.

Currently, over 7 billion of us are consuming about 50% more resources than Earth is producing – during any given time period. For example, in the past twelve months we have consumed the resources that it took the planet about eighteen months to produce. We are consuming our resource base.

Obviously, this 50% overshoot is not sustainable. Another crucial point to understand is this: the longer we overshoot and consume more resources than the sustainable level, the more the long-term “sustainable level” actually declines!

One illustration of this is what’s actually been happening to fresh water aquifers all around the world. Currently over half of us are in countries where aquifers are being overpumped. As “fossil” aquifers are pumped, that water is not replaced. So when that water is depleted, pumping ends since there is no more water flowing in.

Non-fossil aquifers have a “recharge rate” – the rate at which new, fresh water flows in. As long as water is pumped out at or below the recharge rate, the aquifer will continue to supply the same amount of water year after year after year. However, these rechargeable aquifers are being overpumped.

For example, if an aquifer held a million gallons of water, and each year rainfall replenished 100,000 gallons into it, the recharge rate would be 100,000 gallons. As long as everyone collectively pumped no more than 100,000 gallons out, that would be sustainable for years to come. But very frequently people begin pumping more than the recharge rate, let’s say 110,000 gallons the first year, 130,000 gallons the next year and so on. In several more years they might pump over 200,000 gallons out. Eventually they will have pumped all of the million gallons of reserve out. At that point, the annual capacity for that aquifer would fall back to the recharge rate – 100,000 gallons a year. When aquifer reserves are depleted and fall back to the recharge rate, millions of people may suffer! Many other resources are declining in similar fashion.

To become sustainable with Earth’s resources, what are our choices? Reducing overall consumption by 50% would do it for now. Or, reducing population by 3 to 4 billion would do it. It’s more likely that a combination of both – large declines in consumption and human numbers – will be necessary.

Five Earths at American Standard

If all of the world’s 7 billion people consumed as much as an average American, it would take the resources of over five Earths to sustainably support all of them. On average, each American uses nearly 20 acres of biologically productive land and water (biocapacity) per year. 

Earth’s 29.6 billion acres of biologically productive land and water could sustainably support only about 1.5 billion people at an 'American standard of living and consumption.'

At the opposite end of the spectrum are the 1.3 billion people in the world’s poorest countries. Even they are unsustainably overshooting and depleting their resource biocapacity – by over 10%!

During the past decade several researchers around the world have independently concluded that one to two billion is the sustainable number of people (at a European standard of living). Could they be wrong? Download our newsletter to read the article: “Confronting The 21st Century’s Hidden Crisis: Reducing Human Numbers by 80%”.

All of us want a viable, sustainable global home. This can be accomplished only if the wealthier of us reduce our ecological footprint to truly sustainable levels and, if all of us begin now to humanely and dramatically reduce our human numbers.

For detailed information about global sustainability issues, visit FootprintNetwork.org.