MATHIS WACKERNAGEL

MATHIS WACKERNAGEL

Founder & President of Global Footprint Network
Winner of the World Sustainability Award · IAIA Global Environment Award

So shooting for one planet just means you would be totally dominant, and leave no space for other species. Ecologists say to maintain 85% of preindustrial biodiversity, it would take about at least half the planet left on its own. That would mean getting to half-planet. And now we use at least 1.75. I say at least because our assessments with about 15,000 data points per country in a year are based on UN statistics, and their demand side is probably an underestimate because not all demands are included. And also on the supply side or the regeneration side, the UN is very production oriented, so it's the FAO numbers, for example, look at agricultural production, and the depletion side or the destruction side is not factored in adequately. So that's why it's an underestimate. And still, it shows we use about 1.75 Earths, and that's more than three times half an Earth. So that's kind of the difference. But we also know overshoot will end one way or another. The question is do we choose to end it? Do we choose it by design, or do we let nature take the lead and end overshoot by disaster? So it's really ending overshoot by design or disaster. That's the big choice we need to make.

DAVID R. MONTGOMERY

DAVID R. MONTGOMERY

Professor of Earth and Space Sciences, University of Washington · MacArthur Fellow ’08
Co-author of What Your Food Ate: How to Heal Our Land and Reclaim Our Health · The Hidden Half of Nature

When you dig into the medical literature, 7 out of 10 of the leading causes of death in the United States are diet-related chronic diseases. And so one of the hopeful messages that I think comes out of The Hidden Half of Nature, Growing a Revolution, and What Your Food Ate is that what we do to the land, essentially we do to us. And what's good for the land is good for us. So if we think about farming differently, we can actually enjoy ripple effects that are not only beneficial to the farmers in terms of reduced costs for fertilizer, pesticides, and diesel, but it could also translate into better human health outcomes at a population level.