We've used up more resources than the planet can regenerate in a whole year - and it's only the start of August. Mathis Wackernagel of the Global Footprint Network explains why we need to check our overconsumption.
DW talks to Mathis Wackernagel, cofounder of the Global Footprint Network.
Deutsche Welle: What are we actually talking about, when we discuss our ecological footprint?
Mathis Wackernagel: The ecological footprint is a very simple accounting system that looks at the world from a physical perspective, a bit like a farmer. On the one hand, we measure: how much area do we have that is ecologically productive. In other words, how big is our "farm," as a country or region or world, and then we can compare that with our footprint.
That measures how much area is needed to produce everything that I depend on - my orange juice, my potatoes, my cotton - to absorb the CO2 from my fossil fuel burning, to accommodate the cities that we live in. So we can compare human demand for nature with how much nature is available.
You mention CO2. When we talk about the carbon footprint, how does that fit into the ecological footprint as a whole?
The carbon footprint is becoming an ever-bigger part of the ecological footprint. If we follow the Paris [Agreement] goal to stay within 2 degrees Celsius, we would need to have a zero carbon footprint by 2050.
The limiting factor that we face is the earth's ability to renew. We have competing uses for this renewal capacity. One is for food - but if you don't want to increase the CO2 concentration in the atmosphere, we need to put space aside for carbon sequestration, in forests for example, so these are all competing uses.
Currently the carbon footprint makes up more than 60 percent of humanity's ecological footprint. Our economy is built very heavily on fossil fuels, and that's the challenge we face. We have agreed that moving over 2 degrees Celsius is an unacceptable target for humanity. That translates into very clear physical constraints.
The Global Footprint Network says humanity would need 1.6 planets to satisfy demand on the global ecosystem
So what would that mean in practice?
That means we cannot have more than 20 years at current emissions levels. That means, in a very short time frame, we will have to move out of fossil fuel use.
August 8 is Earth Overshoot Day. What does that mean?
It translates our result into something that is easier to visualize. So it says the amount of nature we use from January 1 till August 8 is as much as the Earth can renew in the entire year. So it's as if by August 8, we have spent all the money we have for the entire year.
How do you work that out?
We use United Nations statistics to add up all the demands of humanity - for food, fiber, energy - and we translate that into the area needed to renew these demands. Then we compare this with how much area is available on this planet to renew these materials for us.
Currently we use materials and energy from nature about 60 percent faster than they can be renewed.
Where do we stand in 2016 compared to previous years?
Globally, overshoot is slightly higher this year than last year by our estimates so far. The increase is slower than 10 to 15 years ago, but it is still an increase. Even if you decrease the margin, you cannot stay in overshoot for very long.
If we keep overshooting, that suggests there will come a time where nothing is left. So would we feel the consequences later?
It's a little bit like with money: if you have a lot of assets, you can overspend for quite a while. And nature does have quite a few assets. So the consequences are not too immediate, and they are often distant.
So one aspect is how much CO2 we can emit. Then there are other issues like overusing freshwater, overusing fisheries and so on. We live in a globalized world where we can get food from very distant places, so we don't necessary feel the overuse directly in our lives. We are shielded by high incomes.
But the question is, will we always have the income advantage to get that extra resource? Take for example Switzerland, where I grew up (and Switzerland is not that different from Germany). Its relative income compared to the rest of the world is vanishing, because China or India have higher growth rates.
So relatively speaking, the Swiss are taking home less and less of the global income pie. So that means, if Switzerland doesn't earn as much as the others, it might be difficult to get the resources from elsewhere.
Looking not only at countries like Switzerland and Germany - in terms of justice and equality, it is understandable that people in developing countries say "youcut down first, westill need to expand"?
Of course, everybody wants to have better lives, and everyone should have the right to a better life. That's what we are committed to with the sustainable development goals. But we have to do it in a way that doesn't ruin us.
Some countries are in very difficult positions. India has very little bio-capacity in its own country, and a lower income. And its demand already now exceeds what it has in their own country, twofold. So that makes them extremely vulnerable.
It would be fantastic for everybody to have great lives, but if we drive a development pattern that is very resource intensive, we put ourselves and the lowest income groups at risk first, because we build progress that we won't be able to maintain.
Are there any countries which are good examples of reducing their footprint?
Germany has been a pioneer in the energy transformation and is slowly starting to rebuild its energy system. But it is still quite dependent on resources from abroad. If everybody lived like Germany, it would take about three planets to support this kind of living.
Costa Rica is decarbonizing its electricity system, and has made quite a bit of progress. But overall I would say the speed and scale of transformation is not yet adequate for what we would need to stay within 2 degrees Celsius.
But nobody wants to give up their lifestyle for the planet. I think the point is that it is also for the benefit of each individual actor.
Interview: Irene Quaile-Kersken
Mathis Wackernagel is cofounder of the Global Footprint Network, an international think tank based in the United States, Switzerland and Belgium.