7.3.1. Introduction
A major effort was made within the frames of the EU- financed projects ENSEMBLE
(http://ensemblert3.dmi.dk) and the PRUDENCE (http://prudence.dmi.dk) to predict
regional climatic scenarios and to create future projected climatic files (Giannakidis et al., 2011).
The ENSEMBLE project was an EU funded project (under the 6th Framework Programme), with duration from September 2004 – December 2009. The project was led by the UK Met Office. The partners of the project were mostly from European countries (66 institutes from 20 countries) but also partners across the world were involved. The ENSEMBLE project was based on the results of previous projects like PRUDENCE, STARDEX, MICE and DEMETER. The project informs policy makers (researchers, decision makers, businesses) on the climate and its future changes on a global and regional scale through the use of the latest climate modelling and tools.
The aim of the ENSEMBLES project is to enable to measure the uncertainties in the climate projections in order to predict the future climate. These uncertainties are summarized below:
The size of resolution of global and regional Earth system models developed in Europe and validated across the gridded datasets on seasonal to centennial time- scales.
The representation of physical, chemical, biological and human –related activities correlated with the water resources, the land use, the CO2 concentration.
The correlation of the outputs of the models with applications like agriculture, food chain, water resources, etc (Paul van der Linden and Mitchell, 2009).
The emissions scenarios are developed by the Intergovernmental Panel on Climate Change (IPCC). Four base scenarios have been developed, A1, A2, B1 and B2, with varying weight factors among economic growth, environmental protection, social development and globalization. For the A scenarios, the economic growth is the weighty parameter, whereas for the scenarios B the environmental protection has the primal role. Scenarios 1 assume more globalization whereas scenarios 2 more regionalization. The scenario A1 is split into 3 categories: Α1F, A1B and Α1Τ (Paul van der Linden and Mitchell, 2009).
7.3.2. Emission scenarios for Greece
The climate in Greece is typical of the Mediterranean climate which is mild and rainy winters, relatively warm and dry summers with, generally, long sunshine duration almost all the year. A great variety of climate subtypes, always in the Mediterranean climate frame, are encountered in several regions of Greece, (EMY, 2011). The complex topography of Greece highly affects the regional climate of different regions. The mainland of Greece is divided into two distinct climatic zones by the chain of mountains that is oriented from south to north. Additionally the characteristics of climatic variables as wind velocity, temperature, rainfall and solar energy is diversified in the different regions, i.e. between the mainland and the Aegean Sea, (Giannakidis et al., 2011).
In order to study the emission scenarios, Greece was divided in 13 climatic areas based on its topography (mountain chain, islands), the differences between the continental and insular areas and the temperature differences across the country. Climatic indexes were calculated at 60 stations, as shown in Figure 43 (Giannakidis et al., 2011). The 13 climatic areas are the follows: 1. West Greece (WG), 2. Central and East Greece (CEG), 3. West and Central Macedonia (WCM), 4. East Macedonia – Thraki (EMT), 5. West Peloponnese (WP), 6. East Peloponnese, 7. Attiki (AT), 8. Crete (C ), 9. Dodecanese (D), 10. Cyclades (CY). 11. East Aegean (EA), 12. North Aegean (NA) and 13. Ionian (I). For the above 13 areas, the climatic change was calculated of the mean annual values of six climatic parameters (mean air
temperature (oC), rainfall (mmm/year), relative humidity (%), cloud factor (%), global solar radiation on the ground (W/m2) and air velocity at 10m height from the ground (m/s), for the reference period 1961-1990 and the periods 2021-2050 and 2071 – 2100.
The Research Centre Physics for Atmospheric Physics and Climatology of the Academy of Athens developed climate change simulation data based on the emission scenarios A2, A1B, B2 and B1. The main characteristics of the scenarios are the following (Committee for the Study of Climate Change Impact, 2011):
Scenario A1B: This scenario refers to a socially and culturally unified planet, where the financial growth is occurred rapidly. The energy consumption will be intense as well as the dissemination of energy efficient technologies. The variation of the land use will not be large. The world population will be increased rapidly; by the year 2050 it will reach 9 billion and then it will decrease gradually. Different energy sources will be used (renewable and fossil fuel). The CO2 concentration will increase rapidly during the 21st century and in 2100
will be 720 ppm.
Scenario A2: This scenario refers to a world split in independent nations whose population is growing rapidly. This scenario is characterized by moderate increase in the average per capita income and intense increase of the energy consumption. The technological development will be slow and the variations in the land use will be moderate to large. The CO2 concentration will reach 850 ppm in 2100.
Scenario B1: This scenario refers to a world with increased income per person and low energy consumption; accompanied with reduced use of fossil fuels and increased use of renewable energy sources. The CO2 concentration will increase especially after 2050 and will
reach 550ppm in 2100.
Scenario B2: This scenario refers to a planet that is split in independent nations; however the world environmental consciousness is very developed. Like scenario A2, the growth population will increase but with a lower rate. The decisions concerning the financial, social and environmental issues are made locally. The world financial growth will be moderate and the technological changes will not be as large as these of scenario A1 and B1. The CO2
Figure 44 Variation of mean air temperature between the periods (a) 2021-2050 and 1961 – 1990 and (b) 2071 – 2100 and 1961 – 1990 for the scenario A1B (Committee for the Study of
Climate Change Impact, 2011) (pg 77)
Figure 45 Increase of mean temperature for the different scenarios A1, B1, A2 for the period 1901 – 2100 for Greece (Committee for the Study of the Climate Change Impact, 2011) pg
Figure 44 shows the variation of the mean air temperature between the periods (a) 2021- 2050 and 1961 – 1990 and (b) 2071 – 2100 and 1961 – 1990. It is shown that for the period 2021 – 2050 all areas of Greece are expected to have higher mean annual temperatures by 1.5°C. For the decade 2091-2100, the mean temperature for Greece is predicted to be higher than this of the reference period (1961-1990) by 3.5 oC.
Figure 45 shows that the increase of the air temperature for scenario B1 is milder compared to the other scenarios, A1 and A2. The maximum air increase occurs with scenario A2. For the period 2071-2100, the trend for the air temperature increase is 0.5 oC/decade for scenario A2, 0.4 oC/decade for scenario A1B, 0.25 oC/decade for scenario B2 and 0.1
o
C/decade for scenario B1, (Committee for the Study of the Climate Change Impact, 2011).