Impact of building energy mitigation measures on future climate

Abstract

Abstract As Cities are increasing technological efficacy on greenhouse gas (GH) emissions reduction efforts, the surrounding urban ecosystems and natural resources maybe affected by these measures. In this research, climate indicators such as heat index, extreme hot events, intensified urban heat island (UHI) and sea-breeze are projected for mid and end of 21st century to understand the climate change signal on these variables with and without building energy mitigation measures. Cities amplify extreme heat and UHI impacts by concentrating large populations and critical infrastructure in relatively small areas. Here, we evaluate the combined climate and building energy mitigation impacts on localized climate metrics throughout the 21st century across extreme emissions scenarios (RCP8.5) for the tropical coastal city of San Juan. Analysis of statistically downscaled global circulation models outputs shows underestimation for uncorrected summer daily maximum temperatures, leading to lower extreme heat intensity and duration projections from present time which are corrected using bias corrected techniques. High resolution dynamical downscaling simulations reveal strong dependency of changes in extreme heat events at urban settings, however the intensities shift to lower level grassland and cropland with energy mitigation measures (combination of white roof, tilted photovoltaic and efficient heating ventilation and air conditioning system). The building energy mitigation measures have the potential of reducing the UHI intensities to 10C and 0.50C for 2050 and 2100 climate period, respectively.