Mathis Wackernagel (2015)

1. Earth Overshoot Day can be calculated quite simply. Once we know how much we use, compared to how much we have - that's the ratio between footprint and biocapacity - then we can calculate how many days in the year it would take to use up what we produce in the entire year. So we use about 60% more than what Earth can regenerate, so we're using resources faster, that means if you look at all the dates from January 1st up to August 13th that's the amount of days that can be covered by the 100% and then the remaining days are the other 60% on top that we don't have available for regeneration.

Yeah, offsets for carbon--is that a good idea? I think overshoot and climate change are such serious issues that we need to try anything. At the same time, I'm really skeptical about whether these offsets can be bought that cheaply. The damage per ton of carbon is estimated to be at the order of $40. Anything cheaper, I'd be suspicious of the lasting impact.

Are there sufficient resources to really compensate for those CO2 emissions? The other question is related to transparency.

Some carbon projects do follow quite rigorous standards, so you have to find out if your project that you're supporting does follow these standards. There's an organization called "Gold Standards," I believe, out of Switzerland, that compares the various approaches.

1. Our waste is composed of many different things, including cigarette butts. People get very emotional about cigarettes. Even though cigarette butts are probably a small part of overall pollution, people don't like to see cigarette butts in front of their house or in the park. So that's an issue. But the number of cigarette butts is going down proportionally with the number of cigarettes smoked, so that's a good trend, because obviously it's good for the individuals.

2. I'm sure if we would produce cigarettes that have filters that are degradable (or, as you just mentioned, could even contain seeds that grow), then maybe that would reduce the impact, if the cigarette lands on an area where these seeds can flourish. That's an interesting idea...

Frajer, thank you for your question! We look not just at the carbon footprint, but the entire ecological footprint because ultimately the planet has to provide for everything. Probably around 60 or more percent of the overall demand of the average American is carbon emissions.

How can we reduce it?
One way is the type of energy we use. Do we buy electricity from coal power? Or do we use electricity from photovoltaics (solar).

And also how much we use. We can get the same amount of light from LED for about 1/10th of the electricity as an incandescent bulb.

We can make our houses more efficient. Shorter showers. We can have better insulated houses. We can live in more compact houses. We can live closer to work. We can bike to work instead of driving to work.

You can go to our footprint calculator at footprintcalculator.org to measure your own footprint based on your lifestyle.

Population also comes into play. We can also ask do we want to have a larger family or a smaller family? We can choose. And that has an impact as well.

Great, LPGreen, for pointing out the problem of Australia cutting its carbon tax! Obviously, if you want to reduce our dependence on fossil fuels, including a tax to tax what we don't want would be a great way forward. So Australia has taken a great leap back. What I do not understand is why countries do not compete for higher carbon tax, because they have two choices: They could either wait for energy prices to get higher and keep sending money to countries that sell them the fossil fuels or they can impose taxes and keep the money at home. In the second case, they can use the money to become less dependent on fossil fuels.

Countries that do not have growing carbon taxes are really silly and do not help themselves, in my opinion. They become less and less competitive.

So far it's only noon, and already it's been a pretty cool day. Getting up, I got to see our puppy dog run around and play.

Then my son getting up and going to his wind surfing camp. He's 14 years old.

Talking to various journalists about Earth Overshoot Day coming up.

Then coming here, to San Francisco! I felt like a tourist. The sun is shining.

Like with money, we have annual budgets. If we ran a deficit last year, that accumulates to a debt. It's the same way with our ecological footprint. We calculate a deficit, but then if we have a deficit annually, it builds up to a larger and larger debt.

So the deficit spending this year (we use 60% more than what Earth regenerates) accumulates to the overall debt. As more and more CO2 accumulates in the atmosphere, there's less water in the ground (it's not being recharged as quickly), and more fisheries are suffering, some of them collapsing, soil is being degraded more and more over time--so there is a cumulative effect of the "deficit spending," the same as it is with money. But of course, we can always take a snapshot for each year and say, "This year, have we added to this debt? Or have we paid back the debt?" And through the deficit spending for the year 2015, ecologically speaking, we have added to the debt that we are building up.

Life competes for surfaces. So we can use these surfaces to produce food or timber or build cities - or absorb CO2. And in fact, there's enough space on this planet to absorb all the extra CO2 emitted from fossil fuel. But then you wouldn't have enough space for food, so there's kind of this competition for these uses.

The way we factor it in simply is to look at how much area is needed to sequester the extra CO2 in the atmosphere - and that's by reforesting areas and having long term productive forests that then capture the CO2 and keep it in these forests that take quite a bit of space. But that's the natural mechanism of how to suck CO2 out of the atmosphere for good - building out forests.

TheProfficer, excellent idea! I think the first point is that coercive measures are far less effective than non-coercive measures. It's all about enabling the condition that people see the benefit of having smaller families. Iran for example, about 20 years ago had a brilliant idea; they recognized that their population growth rate was far too high and so what they did is to say 'in order to get married in Iran, first you have to take a class in family planning'. And that was so successful that birth rates dropped more rapidly in 2 years than in China within 20. And in fact, it was so effective that now the government is trying to reverse the policy (not with much success apparently). So, by enabling women to be able to fully participate - to have full access to education and full economic opportunities, that leads very rapidly to smaller families and also much better outcomes for the families - better educational standards, better health...so it's a win, win, win all around. The big problem is that many people are afraid of shrinking populations. The reality in a world of Overshoot is slowly shrinking populations will be, in my opinion, significantly more competitive than those that continue to expand. We don't need to be as afraid of addressing the population dimensions because it's pro-human - we have better outcomes, better lives, more opportunities and ecologically it's a big advantage too.

You already are on the right path! I mean, you've found a lot of interesting subjects and being passionate about these subjects and eager to learn more is the best thing you can do, because as you do that, opportunities and doors will open up. You cannot plan for the future - just get engaged, get interested, be passionate about it! Do it not just because you have to, because it fills your soul and doors will open.

It's always good to have a solid education. Err on the side of taking a few more natural science classes because numeracy is helpful - that's something that's more difficult to learn later in life. It's always a good foundation for anything you do, even if you should choose to become a dentist.

In order to move towards sustainability, we probably need more coordination, so working with each other, which in some other sense means governance, is probably more needed rather than less needed. But it means good governance. Bigger is not necessarily better. We probably need smarter governance.

Back when sustainable development entered the world stage with the Rio Conference, nobody was able to measure how much we used compared to how much we have. That's when we invented the Ecological Footprint to measure "If everyone lived like me, how many planets does it take?"

So it's a very simple accounting framework. It's like a farmer would think, on the one hand, "How big is my farm?" That could be the planet, a nation, or my region. On the other hand, "How much farm does it take to produce everything I consume? How much farm is needed to support me?" Then I can compare how much I use to how much is available. Does it fit? Does it not fit?

So globally now our demand on nature is about 60% larger than what the planet can regenerate. That's why we say it takes 1.6 planets to support that demand, even though there's only one.

That's a fantastic question. Why should we care? It's a bit like if you spend more money than you earn, why should you care about bankruptcy?

What we do with Earth Overshoot Day is try to make our information more understandable. So EOD means by Aug. 13 we have used as much from nature as our planet can renew in a year.

Earth Overshoot Day gives us a better understanding of the world, which can inform all of our decisions. Where should we buy our house? What kinds of transportation should we depend on?

Earth Overshoot Day helps us understand the world a bit better. By Aug. 13, we will have used as many resources from nature as the world is able to use in the entire year.

Great question! By combining all demands on nature into one overall account, the self interest to act becomes much more apparent. Let me explain - if we only focus on CO2, like in the climate negotiations, everybody thinks but doesn't dare to say 'But why should I reduce my CO2? It's good for humanity, but what's in it for me?' and so we keep waiting for everybody else.

We say, the resource situation - if you look at the resources like a farmer - it's more like saying 'if you have a hole in your boat, why should you wait for everybody else to decide first to fix their own boats?'. What's the advantage for you? If you're not ready for the future, you're not ready for the future. So by putting all the resources in one basket it becomes more obvious than if you have a resource risk, it will be your risk - you need to manage your risk, particularly if the others don't seem to prepare themselves. It's even more urgent and significant and important for you to prepare yourself.

Actually, it's all about choice. Physical reality is here to stay, and we can choose: Do we let disaster win or design win? Do we design our way out of the pickle or do we just let disaster take advantage?

If you look at various countries, some have chosen design—for example, Denmark or Germany. They are redesigning their energy systems. Perhaps not at the pace that I would to see, but still, they're proactively looking at it. Other countries have experienced shrinkage of their resource consumption through disaster. If you look at Greece, they had a significant drop in resource consumption because of their economic calamities. Or you see countries like Cuba that went through difficult economic times and had enormous shrinkage. A number of countries have experienced shrinkage through disaster, and that's not what we want.

We can choose. We can choose in our own lives. Also, countries can make that choice. It's all about making sure our beliefs, the way we think the world works, is as consistent as possible with reality. Our beliefs that shape the way we organize development or cities and economies still are not fully consistent with physical reality. Information matters. Good questions matter. Leadership matters. That's why YOU matter.

Probably 'Heidi'. It would be interesting seeing Mike Tyson playing Heidi in the Alps!

Yes!