September 2009 Climate change impacts in Greece in the near future Authored By: C. Giannakopoulos 1 , E. Kostopoulou 1 , K. Varotsos 1 and A. Plitharas 2 1 National observatory of Athens, Greece 2 WWF Greece Introduction The Mediterranean region is mate indicators, associated to vulnerable to climate change extreme climate, were calcu- particularly due to its sensitiv- lated for each selected area. ity to drought and rising tem- The impacts of climate peratures. Climate change is changes are expected to be related to changes in the fre- related with changes in the quency and intensity of ex- frequency of extreme climate treme climate events, which events than to changes in may adversely affect vital eco- mean conditions. This is par- nomic sectors, such as agri- tially attributed to the fact culture and tourism, and have that a change in the ‘mean’ substantive impacts on local climate could cause dispro- communities. In addition, ex- portional changes in the ex- treme climate events can be treme climate events. destructive to human health, Records from the National while climate change may also Statistical Service of Greece have a direct impact on local were consulted in order to people’s lives as it affects sec- set criteria and then select tors such as water resources the 10 representative sub- Inside this issue: and energy. For all these rea- regions for each economic sons, in recent years the sci- sector in question. In particu- Introduction 1 entific community has devel- lar, the urban regions re- The model was developed oped a special interest in search focused on the 10 larg- within the framework of the Urban areas 2 studying potential future cli- est Greek cities based on EC-FP6 ENSEMBLES Project mate changes. their population size. Regard- (www.ensembles-eu.org), by In this study an attempt is 5 ing the agricultural regions, the Royal Netherlands Mete- Tourist areas made to investigate potential the 10 regions occupying the orological Institute (KNMI), at implications of climate change largest numbers of agricul- 25km horizontal resolution Agriculture 7 in the near future (2021- tural workers were selected. and under the IPCC emission 2050) in Greece. Urban, tour- The 10 most important scenario A1B. Two 30-year Forestry 10 istic, agricultural and forest Greek tourist destination periods were considered in areas are selectively examined sites were defined according this study. The present period Conclusions 12 to estimate future climate to the official accommodation is constrained to the years change impacts. In order to capacity (higher number of 1961-1990 and the future achieve this, the Greek region beds available). Finally, the 10 covers the period 2021-2050. was divided into sub-regions largest natural conservation For each of the selected re- which are considered vulner- parks in Greece were studied. gions, maps produced illus- able to climate shocks such as Present and future model data trating the change in extreme extreme temperatures, from the Regional Climate climate indices between the droughts, floods. Subse- Model RACMO2 were used two 30-year periods (2021- quently, several extreme cli- in this study. 2050 - 1961-1990). Climate change impacts in Greece in the near future Urban areas Climate projections for the Urbanization itself greatly needs to range from the cur- Mediterranean suggest that affects surface characteristics rent observed time period the region will become and their interaction with the (using available meteorologi- warmer and drier with more wider atmosphere. This leads cal and sector data) to future frequent and extreme to distinct urban climates that time periods using data from weather events. This presents differ substantially from rural several climate change pro- a threat to urban areas in the environments. The most ap- jections. In addition, a multi- form of increased risks for parent consequence of this is sector approach to climate flash floods and heatwaves. the urban heat island. The change impacts has to be These climate hazards will capacity for the built environ- adopted. Impact sectors inevitably aggravate other ment to store heat during the range from direct climate environmental issues, such as day and release it at night, impacts on natural ecosys- water resource availability, along with the direct release tems (such as flash floods and saltwater intrusion, air pollu- of heat through human activ- forest fire risk) to indirect tion and peri-urban forest fire ity (for example heating or impacts resulting from com- risk. Socio-economic sectors cooling of buildings, traffic, bined climate-social- will also be impacted. Human and human metabolism) can economic linkages (such as health will be a major issue of contribute to higher tem- energy demand, tourism and concern under climate change peratures within cities com- health). Furthermore, the together with the challenges pared to their rural sur- dynamics of the climate sys- of rising energy demand for roundings. The urban heat tem needs also to be exam- cooling and shifts in the sea- island is also sensitive to the ined in an integrated fashion. sonal pattern of tourism. Vul- ambient weather and climate. An indicative analysis of cli- nerability to climate change is In an urban area study, an matic parameters with direct greater for urban areas with integrated approach is re- or indirect implications for limited economic resources, quired across multiple tem- urban areas has been under- rapid population growth and poral and spatial scales and taken for the 10 largest poor planning and regulation. sectors. In the spatial dimen- Greek cities. The locations of Increased frequency of heat- sion, work needs to extend urban areas appear in Figure waves and persistence of high from the inner city bounda- 1, while Table 1 shows their temperatures are the key ries to the surrounding populations. aspects of climate change mountains and forests. In the common to all urban areas. temporal dimension, research Table 1: The 10 largest Greek cities and their populations. Urban area Population Inner Athens 789166 Thessaloniki 385406 Patras 171616 Iraklion 142112 Larissa 132779 Volos 85001 Ioannina 75550 Kavala 63572 Lamia 62452 Figure 1: The 10 largest Greek cities Page 2 Kalamata 61373 Number of days with T >35 oC In Figure 2 the changes in where more than 20 hot the number of days where days per year are expected. temperature is above 35 oC Modest changes appear in are plotted, which is also Athens, Ioannina and Volos expected to have an impact with increases that do not in population discomfort in exceed 15 days, whereas the urban areas. It is evident Iraklion reveals smaller in- that this parameter in- creases of up to 10 days. creases in all selected Greek Regarding this parameter, cities. The largest changes the influence of the nearby seem to occur in the cities sea is playing a dominant of Thessaloniki, Patras, role in tempering the fierce Kalamata, Larissa and Lamia summer heat. Figure 2: Changes in the number of days above 35 oC between 2021-2050 and 1961-1990 for selected regions in Greece. Number of nights with T >20 oC Another parameter very important for the urban areas is the change in the number of warm nights per year. We de- fine these as nights where night-time temperature is above 20 oC and characterise them ‘tropical nights’. In addition, this parameter is closely associated with population health, since a ‘tropical’ night following a ‘heatwave’ day can lead to increased levels of population heat stress and discomfort. Figure 3 displays changes in this parameter for the selected urban sites in Greece. It becomes clear from this figure that tropical nights increase almost everywhere and it is inter- esting to note that coastal urban sites are more affected than continental cities. According to the findings of this figure, all selected urban sites except Ioannina will experience about an extra month per year of warm nights. In Ioannina, the increase will be less than 20 days, possibly due to the cooling effects of the breezes from the nearby Pindos mountains. Figure 3: Changes in the number of tropical nights (Tmin>20 oC) between 2021-2050 and 1961-1990 for selected regions in Greece. Page 3 Climate change impacts in Greece in the near future Energy demands An important implication of require cooling, i.e. an in- demand for heating during climate warming in urban creased use of air condition- the cold period of the year. areas is the increased de- ing. More specifically, 15 From this analysis became mand of electricity for cool- extra days per year will re- apparent that practically all ing in summer. This in- quire cooling in Thessalo- urban areas in Greece will creased demand may cause niki, Larissa and Lamia and experience a decline of the disruptions and overloading 10 extra days in Athens, heating requirements in in the electricity network of Kavala, Volos, Patras, winter season (not shown). the country, which may not Iraklion and Kalamata. The More specifically we expect be able to meet these levels city with the smallest in- that there will be 15 fewer of demand. In Figure 4 the creases is Ioannina with only days per year that will re- changes in the number of 5 extra days requiring cool- quire heavy heating in all days per year requiring ing per year. areas. heavy cooling per year are A positive aspect of climate plotted. It is evident that change in the urban regions more days per year will may be the reduced energy Figure 4: Changes in the number of days with large cooling requirements between 2021-2050