WWF has released a new edition of their “Living Planet Report”. I like this report, for one thing, because it has kept the idea of ecological footprint alive. Ecological footprint was originally developed, or at least widely publicized, in this book in the 90s:
Our Ecological Footprint: Reducing Human Impact on the Earth
Ecological footprint may be the most intuitive way of explaining the idea that humanity is overdrawing the Earth’s resources. The new report puts the ecological footprint at 1.5, meaning 1.5 Earth’s would be required to support our current level of natural resource consumption and waste production indefinitely. To understand how this is possible, imagine you are lucky enough that your parents put a massive trust fund in your name the day you are born. Being born on the Earth is like this. If you are smart, you can live your entire life on the interest, and so can your children and children’s children, as long as they are as smart as you. If you are dumb, you can live an extravagant lifestyle for some period of time, maybe a long time, but eventually it will catch up to you. An ecological footprint of 1.5 suggests that humanity is using up about 1.5 times the amount of natural capital each year that the Earth can support in the long term. Natural capital is the obvious things like fossil fuels and fish, but also less tangible things like fertile soils and the ability of the oceans and atmosphere to absorb our waste products.
The accuracy of Wackernagel’s methods can be endlessly debated, and have been, but the WWF report also has a reader-friendly summary of more recent academic work on “planetary boundaries”. These look at carbon emissions, loads of nitrogen pollution, crop land as a percent of ice-free land, and humanity’s appropriation of primary productivity, among other things. And generally, I think they converge on a pretty similar conclusion that we are living beyond our means and eventually we are going to pay. Normally I try not to shamelessly promote my book, but for my book I made what I think is a pretty cool and useful graphic, which I am sharing below.
Summary of Ecological Footprint and Planetary Boundary Literature
And just in case you think I might be making this stuff up, here are my references:
Rockstrom, J. et al., 2009. Planetary Boundaries: Exploring the Safe Operating Space for Humanity. Ecology and Society 14, 32.
Running, S.W., 2012. A Measurable Planetary Boundary for the Biosphere. Science 337, 1458–1459. doi:10.1126/science.1227620
Wackernagel, M. and W. Rees, 1996. Our ecological footprint: reducing human impact on the earth, New catalyst bioregional series. New Society Publishers, Gabriola Island, BC ; Philadelphia, PA.