Yield to Change: Modelling the Land-use Response to Climate-Driven Changes in Pasture Production

Yields go up – and down    
at times. But farmers respond    
and now we know how.    

In contrast to most economic drivers of land-use change, climate-related drivers display substantial geographic variation. Accounting for this spatial heterogeneity is important in simulations of the land-use response to climate change. I use a discrete choice model to estimate the relationship between pasture yields and rural land use.

Land-use predictions from the model respond to climate change through its effects on pasture yields. This econometric model provides the foundation for the development of a new module of the Land Use in Rural New Zealand (LURNZ) model, the Yield Change Module. In addition to enabling simulations of overall land-use change under different climate scenarios, the module also draws on the estimation results to allocate land-use change spatially.

I employ the Yield Change Module to perform illustrative mid-century and end-of-century simulations of land use in a climate scenario characterised by a high level of greenhouse gas emissions (RCP 8.5). Yield changes in this scenario lead to an expansion (by nearly 600,000 hectares) of dairy area and a fall (by over 800,000 hectares) of sheep-beef area by the end of the century. The implied rate of land-use change is modest relative to that observed in New Zealand’s recent past.