Here you learn about what is valuation, the difference between a price and a value, and various ways to derive a monetary estimate for different ecosystem services. You will also learn about world views that differ radically from the anglo-saxon model with respect to concepts such as "nature" and "biodiversity".

Valuing ecosystem services is a new way of thinking about nature and the environment. Such a change reflects contemporary norms and values, and speaks to contemporary trends in social, cultural, political and economic policies. In this module, you will learn about how the idea of ecosystem services was born, and get a grasp of the specific historical events, places and people who were behind it. You will also understand why it is useful to understand how this approach fits into global trends such as neoliberalism, learn to evalute how you position yourself within these normative and critical perspectives. You will reflect on whether it matters to think about the big picture, and become away of how such an approach can unexpectedly serve to perpetuate unethical or practices

Now that you have learned what are Ecosystem Services, as well as their strengths and limitations to be used in the environment policy arena, you should be curious to know how we can in fact monitor, model and predict their values in space and time. In this module, we will explore how existing data (e.g. elevation, climate, land use, remote sensing) can be used to assess Ecosystem Services through mapping and models. We will then see that once we have a model we can predict the outcomes of different scenarios on the value of Ecosystem Services. Scenarios are themselves particularly useful when interacting with various stakeholders, policy and decision makers. In order to illustrate this process, we present four case studies at various spatial scales: global, European, national and local.

The ecosystem service approach is based on the premise (and promise?) that more sustainable use of natural ressources can be identified through a scientific and social process (Modules 1-4). But how does one get governments (international, national, local) to adopt such practices and then to implement the policy recommendations? This is the challenge of "mainstreaming" a new idea. In this module, you will learn about the challenges and some tips for mainstreaming ecosystem services.

With this last optional module, we would like to give you the opportunity to move from theory to practice by encouraging you to assess a water related ecosystem services (water yield). The aim is to help you discover where you can find useful data to assess ES; how you have to prepare this geospatial data in Geographic information System (here QGIS); how you can use this data to run a simple hydrological model to assess water yield with a dedicated tool with the InVEST package; how you can explore plausible futures of this water resource through scenarios; and finally how you can interpret the outputs of your model as maps in QGIS. Data for a case study is provided with the Tana River basin in Kenya, but you are encouraged to reproduce similar results with your own case study from anywhere in the World. If it will be easier to complete this exercise if you already are somewhat familiar with GIS.