Hi, this is our last sustainability thinking video lecture. I hope that you're getting a good, intuitive sense of what sustainability is about. My goal for this class and the next one is to give you the skills to be able to identify where you can make sustainability improvements in your company or organization. And then be able to make the business case and the sustainability case for implementing those changes. One way to do this would be to give you a list of things to look for at your company to change. The list would probably include things like install more efficient light bulbs, use less paper, conserve water, turn down the thermostat, have a bike to work day, recycle more and try to take fewer business trips on airplanes. All of these are good things to do. But some have a lot more impact than others. And some very high impact changes are probably not on the list at all. Even if you become more rigorous and said, reduce energy use by 10% or increase recycling by 30%, you may not be making the appropriate improvement. In this lecture, I want to introduce a better way to identify potential changes and develop improvement targets. What I'm going to talk about is work by Mark McElroy at the Center for Sustainable Organization. Mark's approach is called context based sustainability. And this has led to an emerging movement called science-based target setting. We'll explore both of these topics, context-based sustainability and science-based sustainability in this lecture and later in the course. Here's the basic idea of context-based sustainability. Ecosystems have limits. They can absorb and process some amount of pollution. So an amount of water can be withdrawn without disrupting riparian areas or depleting aquifers. The ocean can warm up or become slightly more acidic without doing harm to reefs and weather patterns. There are limits to the planet's resiliency and ability to tolerate abuse. If we push too hard on ecosystem limits, we're going to reach tipping points beyond which bad things could happen. You can think of this as carrying capacity. As long as we stay below the carrying capacity of a system we can go on a long time. It's sustainable. But, if we overshoot, which means exceeding that carrying capacity, we degrade the ecosystem so it can only support a much smaller level of activity in the future. Imagine over-grazing range land until all the grass is gone and it becomes a desert. That would be the result of over shooting. An area that once supported hundreds of thousands of grazing animals now supports none. Scientists at the Stockholm Resilient Center have been trying to identify which tipping points we might be approaching. They've surveyed as much scientific literature as they could find and combined all of their results into a chart. The chart tries to capture this notion of limits for nine different environmental measures. The small, blue circle is the safe operating range for planet Earth. The larger, red circle marks the point at which serious problems will begin to occur, i.e., a tipping point's been reached. The chart shows that nitrogen and phosphorus have exceeded their limits and are putting ecosystems at risk. Nitrogen and phosphorus are used in fertilizers. If too much fertilizer is applied, the runoff when it rains carries the excess minerals into rivers and eventually the ocean. And this causes all sorts of problems. Eutrophication and coastal dead zones kill fish, biodiversity loss on land and water, ground water pollution, air pollution from smog that causes respiratory disease. The other danger area is biodiversity loss, largely because of habitat loss for plants and animals. Now let me go back to context-based sustainability. What Mark McElroy and others are arguing for is that we need to set sustainability targets that take these limits into consideration. Saying that a company will reduce its use of fertilizer, that is, nitrogen and phosphorus, by 10% over five years, or its water consumption by 5% over three years doesn't assure any sort of sustainability unless we have some sense of the ecological limits of the nitrogen and phosphorus cycles. Or we know how much drinkable water exists in a region and what other people, species, and ecosystems need from that water. So, to be truly sustainable we have to set targets or limit emissions or consumption levels to be within the carrying capacity of the relavent ecosystems that they impact. Our actions need to be put into the context of our ecosystems. But this is only the first step. There's another, much more difficult step. So step one, recognizing science-based limits for specific types of impacts. Water use, air emissions, soil degradation, and so on. Step two, the first step establishes a limit or a budget for our activity. For example, in a given river system farmers can only use x thousand tons of fertilizer. Or the total global carbon dioxide emissions if warming is to be kept to 2 degrees centigrade or less is say 20 billion tons a year. Step two asks the very scary question of how this budget will be allocated. How much fertilizer will each farmer get? How much CO2 can the US emit? How much can China emit or Iceland, or Kenya, or India. And if we exceed the budget, what does that mean for future generations? Remember our discussion of intergenerational equity? Are we leaving our kids and our grandchildren a huge ecological debt? So when Kellogg's sets its sustainability targets for water use or greenhouse gas emissions, it should be setting them relative to its fair share of water and emissions, given the region's water supply and the planet's ability to absorb carbon dioxide and other green house gasses. This is the very cutting edge of sustainability today. If you could encourage your company or your organization to adopt just one or two science-based or context-based sustainability targets, that would be huge. Then, you would know that your company is doing its part to do no harm to the planet. That would be an absolutely wonderful change to make. Now, I want to take a moment and review what we've covered in the last six lectures. We began with life cycle thinking and the importance of thinking beyond the company's boundaries. We need to consider all the impacts our products have upstream and downstream. And then we compared the standard linear take make waste model to a circular or cradle-to-cradle model. We like circular thinking with reuse and recycling. Next we talked about what sort of world we want to leave our kids and our grand kids. We have to think about the world we're creating for them. We also have to think about repeating dealings with customers and suppliers and communities. So we want to be fair, we want to be nice. We want to make decisions as if we live in a small town. The world isn't linear. It's a complex and messy place, so we need to think in terms of systems and how different things affect our goals. Sometimes relationships change over time and we need to anticipate this as well as we can. Finally, we need to put things into context. That is, we need to recognize caring capacity and planetary boundaries. And we need to stay within those limits. This gives us a budget which needs to be shared. Now I hope you found some new ideas in these talks and that you're developing a strong intuition about sustainability and what it takes to have a sustainable world. Now we begin making the business case for change. Thanks so much.
