PRECIS (Providing Regional Climates for Impacts Studies)
The PRECIS (Providing Regional Climates for Impacts Studies) system has been developed at the Met Office to provide a tool for predictions on a regional scale.
How PRECIS works
PRECIS generates high-resolution climate change information and can be applied in any region of the world.
Adaptation to change will require high-quality climate change information, often with a lot of spatial detail. This is where PRECIS is the ideal tool to use.
Global climate models predict large-scale changes in climate but are not yet capable of providing the fine-scale information, about areas such as mountains and inland water basins, or representing high-resolution climate phenomena such as fronts and cyclones, all of which are needed for some adaptation planning.
Rainfall and crop yield predictions
One of the first applications of the assessment of uncertainty using PRECIS was in the Caribbean and Central America. PRECIS was run using boundary conditions from different global climate models (GCMs).
Sea-surface temperatures are determined by the global models and are very different.
Land temperatures are generated by the regional model and are remarkably similar.
In each case, annual average temperature increases of up to 4 °C by the end of the century are simulated over the land areas, even over the islands. A global model could not reproduce this, as it would not resolve the islands. The consistency of the land temperatures for the two projections gives extra credibility to the results.
Given this level of credibility, it was reasonable to explore the potential impact on key crops for a wide a range of possible changes in rainfall. In all cases yield was predicted to decrease, whether rainfall increased or decreased.