What are regional climate models?

By Doug Moss and Roddy Scheer
Regional climate models offer researchers a focused analysis.
Regional climate models offer researchers a focused analysis.
Dear EarthTalk: What are so-called regional climate models and why do we need them -- given that we already have pretty decent global climate models?    

-- Rich W., Seattle
     Scientists (and economists and businesspeople) love to create models to help predict future outcomes and thus direct their planning and preparedness efforts. Climatologists specifically love models of how the planet and its natural systems and cycles will react to the input of greenhouse gas emissions in the atmosphere. Climate science has come a long way since its early days a few decades back, but most of what we think will happen regarding global warming comes from global climate models—that is, predictions based on empirical data about how much global average temperature is expected to rise and by when.
    “Global climate models simulate the interactions between the atmosphere, ocean and land to project future climate, based on assumptions about future emissions of greenhouse gases,” reports the Climate Impacts Group at the University of Washington.
     According to ClimatePrediction.net, a volunteer computing and climate modeling project at the University of Oxford, England, global climate models are designed to calculate what the climate is doing (in terms of wind, temperature, humidity, etc.) at a number of points on the Earth’s surface as well as in the atmosphere and out at sea. The points are then laid out in a grid covering the planet’s surface. The more points at play, the finer the resolution (and accuracy) of the model.
     Climate researchers are applying what they have learned to look in detail at impacts on a regional basis, especially given that climate change has not only large-scale but local consequences. These regional climate models magnify the resolution of global climate models in a small, limited area, typically within a 3,000-square-mile radius. By creating and analyzing regional climate models, we can assess the influence of myriad fixed geographic conditions and other local factors such as land use, lakes, sea breeze, mountain ranges and localized weather patterns on climate impacts for a particular metropolitan area, state or country.
     “For the practical planning of local issues such as water resources or flood defenses, countries require information on a much more local scale than global climate models are able to provide,” adds ClimatePrediction.net. “Regional models provide one solution to this problem.”
      The Climate Impacts Group has been able to leverage its expertise in global and now regional climate modeling to do groundbreaking research into the likelihood of events such as floods in the Pacific Northwest, expected moisture flux convergence and ensuing drought in the Southwest, and projected climate change and impacts in Southeast Asia. The analytical techniques pioneered at University of Washington are being shared with researchers around the world with the hope that more scientists will run regional climate models to help planners improve people’s lives despite the warming climate.
      Global climate models and regional climate models are both important tools in figuring out how to cope with the effects of climate change, whether a worst case scenario is borne out or something not quite so cataclysmic.


     What will stop global warming?

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