Evaluating the Combined Effect of Climate Change and Urban Microclimate on Buildings’ Heating and Cooling Energy Demand in a Mediterranean City

Stella Tsoka,Aikaterini Tsikaloudaki,Konstantia Tolika,Kondylia Velikou

doi:10.3390/en14185799

Abstract

Climate change has a major impact on the urban built environment, both with respect to the heating and cooling energy requirements, but also regarding the higher probability of confronting extreme events such as heatwaves. In parallel, the ongoing urbanization, the urban microclimate and the formation of the urban heat island effect, compounding the ongoing climate change, is also a considerable determinant of the building’s energy behavior and the outdoor thermal environment. To evaluate the magnitude of the complex phenomenon, the current research investigates the effect of climate change and urban heat island on heating and cooling energy needs of an urban building unit in Thessaloniki, Greece. The study comparatively evaluates different tools for the generation of future weather datasets, considering both statistical and dynamical downscaling methods, with the latter involving the use of a regional climate model. Based on the output of the regional climate model, another future weather dataset is created, considering not only the general climatic conditions, but also the microclimatic parameters of the examined case study area, under the future climate projections. The generated future weather datasets are then used as an input parameter in the dynamic energy performance simulations with EnergyPlus. For all examined weather datasets, the simulation results show a decrease of the heating energy use, an effect that is strongly counterbalanced by the rise of the cooling energy demand. The obtained simulation results also reveal the contribution of the urban warming of the ongoing climate change, demonstrating the need to perform a holistic analysis for the buildings’ energy needs under future climate conditions.

Highlights

Climate change refers to continuous changes in the distribution of weather patterns that range from decades to millions of years [1]
The present study evaluated the impact of climate change and urban heat island on the heating and cooling energy demand of a generic building unit in the city of Thessaloniki, Greece
The study focused on the generation of future weather datasets using statistical and dynamical downscaling methods; regarding the statistical downscaling, the Meteonorm stochastic weather generator was employed, creating a future weather dataset for the year 2050 under the A1B scenario of the 4th IPCC report

Summary

Introduction

Climate change refers to continuous changes in the distribution of weather patterns that range from decades to millions of years [1]. The Mediterranean region is highly susceptible to changes in climate and will be severely affected, as it will become warmer and drier with an increased frequency of extreme weather events, such as heat waves and extreme precipitations [2,3] It has been characterized as a “hot spot” by the scientific community, as the future warming and the decrease in precipitation are expected to be more pronounced in this area in contrast to the global mean change [4,5]. According to the IPCC Fifth Assessment Report [6], the climate system is affected by human activities and anthropogenic GHG emissions, the atmospheric concentration of which have increased significantly during the last years due to the economic growth, the use of natural sources of energy (non-renewable) and population growth The effects of these concentrations in the climate system, combined with those of other anthropogenic factors (e.g., land-use change), may be the main cause for the observed rise in temperature since the mid-20th century. The continuous emission of GHGs will lead to further warming and long-term changes, causing more severe effects to humans and ecosystems

Methods

Results

Conclusion