Ecological overshoot keeps growing. As a result, humanity is facing a ballooning ecological debt. Since our planet cannot be depleted forever, overshoot will eventually end. The question is whether this will happen by design or disaster.

So, how do we design our future? The beta version of this simple tool allows you to design possible futures by choosing key parameters that shape overshoot: how much each of us will use, and how many of us there will be on the planet. You can also choose how quickly the change in consumption and family size may happen. What do your explorations reveal?

Tool code updated 9/23 10:26am by Amanda

Data sources include the National Footprint and Biocapacity Accounts, the UN Population Programme, and the World Bank. The full population model powering the scenario tool’s population projections is available here.

The purpose of this tool is to explore a range of outcomes humanity could generate. Play with the levers to shift the trajectories.

Ecological debt: The number on the right of the scenario tool shows you how much ecological debt will have accrued by the end of the century. The ecological debt is the sum of the yearly deficits. Like with money, this year’s deficit increases the already accumulated debt. From the early 1970s, when humanity crossed for the first time into global overshoot, to 2022, humanity has accumulated the equivalent of 20.5 Earth-years of ecological debt. This means the ecological debt is as large as what the planet’s ecosystems can regenerate in 20.5 years. A big portion of the debt is the accumulated greenhouse gases in the atmosphere. It is not clear how much ecological debt the biosphere can tolerate. What we know is that the current debt is already pushing the planet into unsafe territory.

Also note the optimistic nature, or rather limitation, of this tool. It optimistically assumes that the growing ecological debt will not reduce future biocapacity. In reality, ecological debt may well erode our planet’s biocapacity, whether through soil erosion, freshwater shortage, climate change or biodiversity loss. This would imply that overshoot may need to be curbed faster than the scenario tool suggests. Otherwise, reductions by design will not be able to outpace reductions imposed by disaster.

The population scenarios are calculated with our cohort model available for download here (2021 version). To explore variances in per person footprints, you can use our personal Footprint calculator.

The future of this tool: With additional resources, Global Footprint Network plans to expand upon this beta version to make the tool more versatile. For example, we will break down population side and the consumption side into more parameters. For instance, consumption could be split into different categories, so one could choose how much we will reduce carbon emissions and how much of that reduction will truly vanish. This is because some of the carbon reduction could simply shift pressure onto other Footprint categories such as when biofuels are used rather than fossil fuels, or when cotton replaces synthetic fibers). You could also be able to choose how much humanity reduces its biological resource use, for instance, by using less animal-based food, or by using biological materials longer. We would also love to add choices for strengthening (or weakening) our planet’s biocapacity.

The population side is complex, because family size is influenced indirectly: as women and men start to have equal rights and opportunities, family sizes shrink, markedly. Also, access to reproductive health reduces family size and leads to longer and healthier lives for all family members. In contrast, imposed family policies typically backfire: their effectiveness is minimal, and they cast long shadows of psychological and cultural wounds.

Additional Resources
• Check out Ecological Footprint and biocapacity data for countries from 1961 to today
• Learn about the factors that determine ecological overshoot. These are also the five key solution areas
• Calculate your personal Ecological Footprint
• Find out more about the population dimension
• Should we even talk about population?
• Download and play with a population cohort model Global Footprint Network assembled (2021 version). It allows to calculate implications of changes in fertility, mortality, and average age of mothers.
• Explore existing solutions
• Add solutions you love to the #MoveTheDate map

We’d love to hear your feedback on the tool. Use the form below to share your comments or concerns.