General Information on Local Climate Change Scenario of Andalusia updated to the 5th IPCC Report

The Andalusian Environmental Information Network (REDIAM) has produced a series of regionalised climate scenarios for Andalusia based on the report (AR5) of the International Panel for Climate Change (IPCC). Future simulations have been generated in three periods (2011-2040, 2041-2070, 2071-2100), for 9 General Circulation Models (GMCs), in 4 emission scenarios (CPR26, RCP45, RCP60 and RCP85) and the climate reference scenario representative for the period 1961-2000. This project is called “Local Climate Change Scenarios updated to the 5th IPCC Report”, whose main objective is to publicise scientists, technicians, politicians, administration, businesses and citizens in general, the expected effects of Climate Change on the Andalusian region on a semi-detailed scale — trying to reflect the climatic variability that characterises it-, a basic information for the development of adaptation policies.This simulation has led to a multitude of territorial studies that allow to know the impacts of climate change in sectors such as the environment, agriculture, health, industry, tourism, etc. “Information Relating to General Circulation Models and Scenarios” The main tool for climate prospecting for the coming decades are the so-called Numerical Climate Prediction Models (MPNCs) or as they are commonly known, General Circulation Models (MCGs). These models (Gordon et al., 2000; Stendel et al., 2000) simulate flows of energy, mass, and amount of motion, using primitive equations of dynamics, between the points of a three-dimensional grid extending across the Atmosphere and Oceans and the upper layers of the Lithosphere and Crioosphere. Through the temporary integration of these flows, simulated evolutions of the atmospheric states are obtained. There are different types of models, depending on the dimensions in which you work, are distinguished: models in 1D (energy balance, convective radiation models), in 2D (height-latitude plane) and 3D (MCGs; atmosphere, ocean, atmosphere-ocean). More modern CGMs include layers in the lower and middle stratosphere, as recent studies show their influence on the climate system (Smagorinski, 1965; Manabe and Hunt, 1968), and is expected to be included in the next IPCC. Since 1990 it has been working with atmosphere-ocean coupled models and these are those included in the fourth IPCC report and which are currently being worked on. CGMs have three main characteristics: resolution, formulation and configuration. Since models are integrated for extended periods of time (from weeks to hundreds of years), it is more important that they represent the general circulation of large areas than the specific details of time in localised areas, so a resolution of several degrees of latitude/length is sufficient. The formulation refers to the mathematical resolution of the models (grid or spectral). Finally, the configuration is the way a CGM is executed: there are two types of models, atmospheric and coupled (atmosphere-ocean). The first are atmospheric models that represent the interaction with the ocean by introducing fixed temperature data on the sea surface, while in the latter, an ocean model is responsible for simulating changes in sea temperature being able to react to possible atmospheric changes. The latter are the most used today. The above characteristics are those that will distinguish some models from others, especially their resolution, that is, the size of the grid on which they work. Another characteristic that differs them is their resolution in the vertical and which reports the pressure levels. The most advanced CGMs initialised their simulations in the early 19th century with the radioactive forcings of the pre-industrial era. During the temporary integration these forcings are modified in accordance with the records or estimates of historical concentrations of greenhouse gases and aerosols, when the integration reaches the current moment and becomes internal in the future, the concentrations of these agents are estimated according to the forecasts of human activity: these are climate change scenarios (Nakicenovic & Swart, 2000). CGMs show a remarkable ability to reproduce the main characteristics of the general atmospheric circulation, such as “hadley cells”, extratropical belts of borscas, etc. (Stendel et al., 2000). The problem arises when the results are checked on a smaller scale (i.e., a few points are selected from the working grid) where the variables, especially on the surface, do not approximate the values actually observed.