Ecosystem services

<v ->Welcome to step four,</v> hopefully by this time you’ve had a chance to look at the Wardian Case and get some idea about how environmental science works and all the different aspects and perspectives we use in environmental science. One of the cool things I want to show you today is about ecosystem services, what they are? how they’re valuable to us? and how human activities degrade those ecosystem services? and behind me here is the cowboy stadium in Townsville, Australia and you’ll notice that it’s sitting right on the edge of this beautiful mangrove, right pairing area and mangroves are really important and around the world mangroves provide a really important set of ecosystem services, but what are ecosystem services?

Ecosystem services arise from a healthy, normal functioning, natural environment. And that gives us services, sometimes we don’t even realize. From filtering our water, providing protection from storm surge during cyclones, all of these services provide value to human societies and because they provide value, we can calculate how much in real world dollars that value is. How much would it cost us to build a sea wall that provides equivalent protection to a mangrove forest? How much would it cost to filter the water that a natural wetland might filter for us? Globally natural ecosystems provide four and a half times the gross world product in ecosystem services. That’s roughly in us dollars 375 trillion dollars per year.

Whether it’s filtering water, protecting our coastlines from storm surges, creating oxygen from the rain force of the world. All of those things are really, really important and they have value to us whether we realize it or not. And so being able to quantify the value that an ecosystem provides to us gives us a means to also protect that ecosystem in some cases and so it’s really important that we recognize not just the natural services that ecosystems provide for us, but the real, tangible and important services that ecosystems provide to human society.

Ecosystems are degraded in a couple of ways, they can be degraded naturally or by humans in natural cases, things like volcanic eruptions, cyclones, any kind of large scale disturbance, bushfire can cause an ecosystem to lose its ability to provide those services. Think about a bush fire or a forest fire. It goes through and if it burns up and it’s really hot and intense, it will remove the ecosystem service that that forest provided and that’s erosion control and water filtration.

So all of a sudden you have a landscape that’s denuded of trees and vegetation and when rainfall falls on that slope, that water will erode the soil on that landscape and that water will then flow into rivers, where it’ll be more turbot or muddier and harder for us to use as drinking water and also we’ll lose the soil on that force floor and it’s possible that that forest won’t be able to grow back as easily. Now, humans degrade ecosystem services as well. If you look at this stadium behind me, it looks beautiful, there’s still a mangrove forest in front of it but that mangrove forest is just a thin narrow 20 or 30 meter strip of mangroves.

It used to be a mangrove forest much more extensive than what’s there now and its ability to provide ecosystem services for us has been greatly impacted by human development around it And we’ve narrowed it’s, we’ve narrowed it’s scope and we’ve limited its function. Globally human activities degrade ecosystem services by four to 20 trillion dollars per year. So remember that first number we talked about that 375 trillion dollars per year, every year that’s reduced through human development, landscape use and to some degree natural disasters. In some cases there’s environmental problems where the solution is to build an ecosystem, where I used to work in Tucson, Arizona. It was really interesting, wastewater was a big problem. How do we filter it?

And because this the river that the wastewater went into was very dry a lot of the years, it was really important to clean that wastewater well before it left the wastewater treatment facility. One of the solutions that was developed was to build an ecosystem, a wetland ecosystem right next to the wastewater treatment plant and all the wastewater that came out of that treatment plant would run into that wetland ecosystem and through the action of bacteria and plants and even birds and bees and insects that water was cleaned to a better standard than it had just came out of the wastewater treatment plant and when it was released into the environment, it was cleaner and better and everybody wins.

The birds got a place to shelter on migratory routes, that aquatic animals and plant life had a place to live and so in that case, we actually recreated an ecosystem to provide an ecosystem service and that’s really the power of ecosystem services. We can use them, we can preserve them to help us maintain our ecosystem services or in some cases if we need to, we can rebuild ecosystems to provide those services for us once again.