One way that climate models are tested and improved is through a “model intercomparison project”. A number of modeling groups get together and use a collection of models to run the exact same simulations with the exact same inputs to see how the results line up. This can be done to generate collective projections of temperature change or just to look for parts of individual models that need work. Projects like these have been organized for a number of different types of models, but a new one examines models of climate change impacts.
A pile of papers published in the Proceedings of the National Academy of Sciences present the first fruits of the Inter-Sectoral Impact Model Intercomparison Project. This is the first time that models of things like water availability, crop yields, and malaria have been evaluated together. The organizers hope the project will not only provide the best available information to folks planning for (and dealing with) the impacts of climate change, but also help guide the research community towards the questions most in need of answers.
One of the studies, from a large team led by Jacob Schewe at the Potsdam Institute for Climate Impact Research, used models of Earth’s water cycle to examine the availability of the liquid in a warming world. Because warmer temperatures result in more evaporation and more intense precipitation, arid regions are generally expected to get drier, and wet ones wetter. Given that access to water is already a problem in many places, anything that exacerbates that situation is a step in the wrong direction.