Applying Occam's razor to global agricultural land use change

Kerstin Engström,Mark D.A Rounsevell,Dave Murray-Rust,Catherine Hardacre,Peter Alexander,Xufeng Cui,Paul I Palmer,Almut Arneth

doi:10.1016/j.envsoft.2015.10.015

Abstract

We present a parsimonious agricultural land-use model that is designed to replicate global land-use change while allowing the exploration of uncertainties in input parameters. At the global scale, the modelled uncertainty range of agricultural land-use change covers observed land-use change. Spatial patterns of cropland change at the country level are simulated less satisfactorily, but temporal trends of cropland change in large agricultural nations were replicated by the model. A variance-based global sensitivity analysis showed that uncertainties in the input parameters representing to consumption preferences are important for changes in global agricultural areas. However, uncertainties in technological change had the largest effect on cereal yields and changes in global agricultural area. Uncertainties related to technological change in developing countries were most important for modelling the extent of cropland. The performance of the model suggests that highly generalised representations of socio-economic processes can be used to replicate global land-use change.

Highlights

Land-use is a crucial link between human activities and the natural environment (Foley et al, 2005)
We conclude that the generalised process representations of the parsimonious land-use model (PLUM) model captures the essential dynamics of global agricultural land-use in response to our initial research question: “Can the temporal trends and spatial patterns in global agricultural land-use be understood from simplified socio-economic processes at the country level?” In spite of the limitations in modelling unforeseen, rapid and extreme events, simple supply and demand processes, driven by population, economic development, life style choices and technological change offer insights into understanding the temporal trends of global agricultural land-use change
The inclusion of biophysical information about land suitability and yield development would be a valuable addition to the model in order to improve performance at the country level

Summary

Introduction

Land-use is a crucial link between human activities and the natural environment (Foley et al, 2005). Land-use intensification has caused detrimental environmental impacts such as salinization, biodiversity loss, and groundwater pollution and depletion (Foley et al, 2011). Expanding agricultural areas encroach on natural ecosystems resulting in deforestation, conversion of natural grasslands and wetland drainage. These changes are predicted to have far-reaching consequences, impacting on many aspects of the Earth system (Foley et al, 2011). Knowledge about land-use change (LUC) is important, in understanding how to feed a growing global population whilst simultaneously avoiding environmental damage

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