Carbon emissions from land-cover change
Introduction
This assignment represents the first lab of this course, that we are doing in R. The reasons for switching to R are manifold. On one hand, in the model we will apply there won’t be any feedback loops incorporated, which makes the use of Vensim not necessary. On the other hand, it builds on good student’s feedback from previous years that (a) the implementation is easier in R compared to Vensim and (b) more generally suggested to keep R as a component of this class to maintain practicing the scripting language. Lastly, it is always a good training to keep using multiple software packages in tools in order to be able to adapt to different environments and systems.
Specifically, we will work with a Carbon Bookkeeping model (CBKM) that has been introduced to the land use / climate change community by Richard Houghton1 and that has been modified in different land-use contexts. The CBKM allows us to calculate carbon emissions from land-use change. It is a simple model that is based on the idea of stocks and flows, where stocks are the amount of carbon stored in a certain pool (e.g., aboveground biomass, soil organic carbon) and flows are the changes in these stocks over time (e.g., emissions from deforestation). The model is designed to be flexible and can be adapted to different land-use changes and regions. Our study case will be the Gran Chaco in South America, which is a global deforestation hotspot where during the past 35 years more than 30% of all woodlands have been disappearing for establishing croplands or pastures. These land-use changes have resulted in major carbon emissions, which have been quantified using the same approach that we will use for this assignment2. Compared to the paper take as the example for this lab, we will run the estimations with updated data. However, the paper contains all necessary coefficients you need to correctly implement the CBKM.
The assignment goes over two weeks. In week 1, you will implement the CBKM in R while receiving substantial guidance from us. WE will discuss the outcome and the techniques in class. In week 2, we then want you to adapt the code and parameterization to address a new question.