Dennis Forster (p), Jonas Hahn, Novak Kostic

Hiroaki Shirayanagi

Buildings are a significant cause of carbon emissions and considered a key driver of climate change. These emissions comprise both those locked in the building substance (‚grey energy‘) as well as emissions from ongoing energy consumption from building operation during a long-term lifecycle of decades. In recent years, the occurrence of extreme weather events has increased substantially in frequency and intensity and through the greenhouse effect, there is a mediate effect from a building’s energy attributes. Public regulations, including the introduction of carbon taxes, aim to increase the incentive for owners and operators of commercial property to improve energy efficiency. In this paper, we investigate whether there are also market-based mechanisms in pricing patterns, focusing on so called ‚green premiums‘. Leveraging experimental machine learning (ML) approaches, we specifically assess the relevance of energy consumption on property prices and whether higher achievements in energy efficiency come with a discernible price premium. Our analysis draws insights from an exemplary dataset comprising approximately 9,200 office property market transactions in Singapore spanning from 1995 to 2022. The identification of such ‚green premiums’ could serve as an additional incentive for market players, aside of saving funds from avoided carbon taxes and damages from lower levels of extreme weather, to invest in upgrading their properties or acquiring more energy efficient buildings, fostering a more sustainable trajectory for the real estate sector.

Theodoros Chatzivasileiadis (p)

Dennis Forster

This study explores the long-term economic consequences of sea-level rise (SLR) on coastal areas in Europe, emphasizing its impact on Gross Domestic Product (GDP). By analyzing a unique dataset that tracks regional SLR and economic growth from 1900 to 2020, we examine the correlation between SLR and GDP per capita across 79 coastal regions of the EU and UK. Our findings indicate that the current levels of SLR have already adversely affected the GDP of these regions, culminating in a total GDP reduction of 4.7% at a 39 cm rise in sea levels. Over the past 120 years, the influence of SLR on annual GDP growth has ranged from a decrease of 0.02% to an increase of 0.04%.

Further analysis of historical data for EU and UK NUTS2 regions from 1900 to 2020 demonstrates the impact of SLR on European regional economies, particularly after 1980. For every additional meter of sea level, the immediate GDP impact is estimated at -13.8%, while the long-term effect is -9.6%. This variance is attributed to adaptive measures as outlined by Merel (2021) and Dell (2009). Initially, investments in protection redirect capital away from more productive activities, leading to a short-term economic downturn. However, over a 10-year period, the overall effect of these investments reduces to nearly half (-7.2%) due to the dynamic redistribution of resources.

Extrapolating these insights to future climate and socio-economic scenarios, we predict that without further adaptation measures, GDP losses by 2100 could range between -6.3% and -20.8% under the most severe SLR scenario (SSP5-RCP8.5 High-end Ice) or -4.0% to -14.1% in a less severe scenario (SSP5-RCP8.5 High Ice). These empirically grounded projections suggest that GDP losses in 2100 could range between -4.6% and -14.1% across coastal EU and UK regions under the extreme SLR scenario (SSP5-RCP8.5 High Ice), assuming current adaptation levels.

This century-long statistical analysis provides a vital empirical basis for developing regional climate adaptation strategies aimed at reducing economic damages due to SLR. Our evidence advocates for strategic asset relocation and the establishment of coastal setback zones where economically and socially viable. This approach is supported by the observed economic impact of protection investments. The study underscores the importance of dynamic, region-specific responses to climate-induced economic challenges.

Hiroaki Shirayanagi (p), Yukisada Kitamura

Theodoros Chatzivasileiadis

　When residents evacuate from water-related disasters such as river floods, storm surges, and tsunamis, vertical evacuation is also important in addition to horizontal evacuation because the time spent in lowland areas should be reduced as much as possible. However, the current evacuation plans for flood disasters are based on the assumption of horizontal evacuation to shelters. Therefore, this study uses data from a 3D urban model (3D PLATEAU) to construct vertical–horizontal evacuation simulations, estimate the number of people temporarily accommodated by rooftop evacuation measures in the case of a large-scale storm surge and tsunami in Konohana-ku, Osaka City, and quantitatively evaluate the disparity between the two areas.
　Out of a daytime population of 1,777 in Kasugade-kita 1-chome, 1,116 people were found to need to evacuate in the event of a tsunami and 1,421 people were found to need to evacuate in the event of a storm surge. However, only one building in Kasugade-kita 1-chome has been designated as a tsunami evacuation building by Osaka City, and its estimated capacity is 501 people, which is significantly insufficient. Therefore, we estimated the number of people who could be temporarily accommodated if the rooftop of an RC building, which is less likely to collapse or spread fire, were used as new evacuation sites. We found 45 buildings (including tsunami evacuation buildings) with rooftop evacuation sites, and an estimated number 2,045 temporary evacuees that could be accommodated. In the event of flooding, the maximum number of people that cannot be accommodated in evacuation buildings in Kasugade-kita 1-chome is 920. If approximately 45% of the buildings have rooftop evacuation sites that can be accommodated, it is theoretically possible to temporarily evacuate all residents in this area.
　In the entire Konohana Ward, it is clear that, if the rooftop of an RC structure can temporarily accommodate 100% of the population, it is possible to create a temporary evacuation site for approximately 200,000 people (approximately 2.3 times the daytime population and 3.0 times the nighttime population). If the rooftop evacuation measures proposed in this study can be realized, the feasibility of vertical and horizontal evacuation for water disasters such as tsunamis and storm surges can be increased.