Observations and models
Climate change affects whole ecosystems and landscapes; hence, the research goes beyond the usual dimensions of a laboratory experiment. Therefore, besides laboratory work and observations, climate researchers often rely on experimental models. They simulate possible climate outcomes depending on different scenarios and calculate the probability of their occurrence. Complex climate models include as many determining factors as possible and hence, can be used as a time machine: they offer a clearer picture of past climatic highs and lows, and provide an increasingly more precise view of the climate of the future. Climate models are used in combination with ecosystem or water resource models to estimate the consequences of climate change.
The NCCR Climate unravels climatic processes with far-reaching consequences. For example, it was determined that a critical factor of the heat wave in the summer of 2003 was the water resources. If the soil is completely dry then much less evaporation energy is used causing the air temperature to rise.
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NCCR Climate specialists from very diverse areas of climatic research are working together and within the framework of a broad research program they all gain from each other's know-how. By combining different research approaches and methods, new knowledge is created that can only come out of interdisciplinary co-operations. Biologists from the University of Basel, for example, are studying the effect of increased CO2 concentrations in the atmosphere on the water use of different tree species. In a field experiment, which is a first of its kind, CO2 is being continuously fed into part of a forest in order to create future atmospheric conditions. The trees are being observed from above using a crane. In another project, forest ecologists from the ETH Zurich are using a combination of forest and hydrology models to simulate the effects of climate change on different ecosystems and ultimately on Swiss forests as a whole. Using the data collected from the crane experiment they can determine the future species composition of forests. The results from these two projects are then applied to a third research project. Evaporation measurements and forest simulations help climatologists from the ETH Zurich to further develop a regional climate model. Since they include parameters that closely refl ect reality, the model gains accuracy. It is now possible to calculate scenarios that include the effects of land use changes to the earth's surface and tree evaporation on the regional climate. Hence, the researchers from Basel can use this information in their experiment in order to expose the trees to more realistic future climate conditions. This is achieved by using a climate chamber on the tree that simulates rising temperatures. With this the experiment becomes more credible. |
Swiss National Science Foundation.