Urban Forestry & Urban Greening 14 (2015) 99–106 Contents lists available at ScienceDirect Urban Forestry & Urban Greening journal homepage: www.elsevier.com/locate/ufug Growing cities in Serbia in the light of projected global warming: The situation in urban morphological zones Stojanka Radulovic, Aleksandar Bobic ∗ , Jasminka Cvejic, Andreja Tutundzic University of Belgrade, Faculty of Forestry, Kneza Viseslava 1, 11 000 Belgrade, Serbia article info Keywords: Average Euclidean distance Climate change Compact city Green infrastructure Soil sealing UMZ abstract In light of the expected climate change in the coming decades and for the purposes of this study, the geographical positions of five growing cities in Serbia were analysed. This analysis was followed by an analysis of the dynamics of these cities’ urban morphological zones (UMZ) from 2000 to 2006, as well as an analysis of the soil sealing degree within the UMZ and the average distance between non-built tissues. The results were compared to the results from other European cities, as well as to the concept of the Compact City. This research determined the expansion of the UMZ, especially along traffic arteries, which may intensify the urban heat island (UHI). In addition, the soil sealing, i.e., the size of the porous heterogeneous land covers (e.g., green urban spaces, sport and leisure facilities, deciduous forests, and rivers) and their respective average Euclidean distances within an UMZ, indicate the potential to lower the temperature on the micro level. Given that the condition of the morphology of growing cities will be, according to the projections, in the region that is particularly affected by the increase in the number of hot days and tropical nights (CHT), as well as by the heat index (AT105F), new strategies and plans will be required to adapt the cities to the impacts of climate change at the local level. In this sense, using the experience of other cities in the Mediterranean region should be one of the pillars, especially as the changes have already begun and are rapidly occurring. © 2014 Elsevier GmbH. All rights reserved. Introduction In Europe in the previous decade (2001–2010), several summers were amongst the hottest in the last 500 years; in the Balkans, one of these summers was that of 2007 (Barriopedro et al., 2011). Climate change scenarios suggest that the increased likelihood of mega heat waves (prolonged heat waves over a large area) in densely popu- lated areas of Europe (Barriopedro et al., 2011) is highly probable in terms of the length, frequency and/or intensity of warm spells or heat waves (IPCC, 2012; Kuglitsch et al., 2010). Heat wave is defined as a period of at least six consecutive days with a daily maximum temperature higher than the 90th percentile for the control period (1961–1990) (Fischer and Schär, 2010). The prolon- gation of the heat wave combined with high night temperatures and high relative humidity contribute to increased mortality. High relative humidity is a particularly important stress factor for human ∗ Corresponding author. Tel.: +381 604010111. E-mail addresses: stojanka.radulovic@sfb.bg.ac.rs (S. Radulovic), aleksandar.bobic@gmail.com (A. Bobic), jasminka.cvejic@sfb.bg.ac.rs (J. Cvejic), andreja.tutundzic@sfb.bg.ac.rs (A. Tutundzic). thermoregulation. When the relative humidity is high, the rate of evaporation is reduced, which reduces the efficiency of this mech- anism (Sherwood and Huber, 2010). An important indicator of the impact on population health is a combination of hot days and trop- ical nights (CHT) with maximum temperatures above 35 ◦ C and minimum temperatures above 20 ◦ C, as well as the influence of the combination of high humidity and high temperatures – AT or a heat index (AT105F – apparent temperature) exceeding 40.6 ◦ C. The above-mentioned combination leads to heat stress (Diffenbaugh et al., 2007; Basu and Samet, 2002). According to the projections of Fischer and Schär (2010), major changes regarding the CHT and AT105F, and therefore the most serious impacts on the health of people, will occur in low elevations along the Mediterranean coast and basins primarily of the Po River and the lower part of the Danube in regions of southern Europe with densely populated cen- tres (e.g., Athens, Bucharest, Marseilles, Milan, Rome or Naples). The research results are somewhat alarming, especially as used models did not consider the effect of urban tissue. However, when the pro- jections of climate change include urban models with a doubling of CO 2 (Fischer et al., 2012), the results indicate large differences in the temperature and humidity at night and a slight difference dur- ing the day for urban vis-à-vis rural areas. Projections also indicate http://dx.doi.org/10.1016/j.ufug.2014.12.002 1618-8667/© 2014 Elsevier GmbH. All rights reserved.