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Table of Contents

  1. Introduction: AIACC: Climate Change and Conservation Planning
    1. Chapter1: Evidence for climate change
      1. Chapter 2: Global circulation models
        1. Slide 1: Global Circulation Models - the basis for climate change science
        2. Slide 2: Weather prediction
        3. Slide 3: NWP vs climate models
        4. Slide 4: NWP vs climate models (cont)
        5. Slide 5: How does the climate work?
        6. Slide 6: The atmosphere I: vertical structure
        7. Slide 7: The atmosphere II: energy budget
        8. Slide 8: The atmosphere III: Horizontal transfers
        9. Slide 9: The oceans
        10. Slide 10: Biosphere
        11. Slide 11: The geosphere
        12. Slide 12 : Different types of climate models
        13. Slide 13: Energy balance models
        14. Slide 14: Radiative-convective models
        15. Slide 15: Statistical-dynamical models
        16. Slide 16: Global circulation models
        17. Slide 17: Contemporary GCMs: an outline
        18. Slide 18: Climatic processes modelled in a GCM
        19. Slide 19: Flux adjustments
        20. Slide 20: How many GCMs are there?
        21. Slide 21: Use of GCMs
        22. Slide 22: Climatic forcing
        23. Slide 23: The effects of current radiative forcings
        24. Slide 24: IPCC future scenarios
        25. Slide 25: Development scenarios (cont).
        26. Slide 26: Future radiative forcings depend on response
        27. Slide 27: GCM model responses
        28. Slide 28: GCM outputs for 2100 (I)
        29. Slide 29: GCM outputs for 2100 (II)
        30. Slide 30: Linear and non linear responses
        31. Slide 31: Examples of non-linear changes
        32. Slide 32: Conclusion
        33. Slide 33: Test yourself
        34. Slide 34 Links to other chapters
      2. Chapter 4: Biodiversity responses to past changes in climate
        1. Chapter 5: Adaptation of biodiversity to climate change
          1. Chapter 6: Approaches to niche-based modelling
            1. Chapter 7: Ecosystem function modelling
              1. Chapter 8: Climate change implications for conservation planning
                1. Chapter 9: The economic costs of conservation response options for climate change
                  1. Course Resources
                    1. Practical: Conservation for Climate Change
                      1. Tests to Assess your Understanding
                        1. How to run a GAM model in R

                          Slide 17: Contemporary GCMs: an outline

                          Duration: 00:01:27


                          GCMs are involved incredibly complex calculations of atmospheric functions, and the best we can manage within the auspices of this course is a brief outline of their function. The most complex current models are known as coupled atmospheric ocean general circulation models (AOGCMs).

                          They have between 10 and 20 layers in the atmosphere, and as many as 30 layers in the ocean.

                          Contemporary AOGCMs have a horizontal resolution of between 250km and 600km.

                          For local planning, this is a very coarse scale, and the underlying topography is poorly represented. If necessary, results can be scaled down post hoc using a series of modelling functions (or by using regional modelling), but this is a complex and as yet, relatively inaccurate process.

                          However, taken over the whole globe, this resolution results in an extremely large number of individual cells. (1.5 million oceanic cells, and approximately 250 000 atmospheric cells).

                          For a given time step, calculations are carried out for each of these cells over the whole globe, including energy exchanges between each of the 26 adjacent cells.

                          Clearly this is very computationally intensive, and it is no surprise that atmospheric predictions have been at the forefront of computer development since the early 1950s.