Impacts of Climate Change on Extreme Climate Indices in Türkiye Driven by High-Resolution Downscaled CMIP6 Climate Models

Abstract

In this study, the latest release of all available Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models with two future scenarios of Shared Socio-Economic Pathways, SSP2-4.5 and SSP5-8.5, over the period 2015–2100 are utilized in diagnosing climate extremes in Türkiye. Coarse-resolution climate models were downscaled to a 0.1° × 0.1° (~9 km) spatial resolution using the European Centre for Medium-Range Weather Forecasts Reanalysis 5-Land (ERA5-Land) dataset based on three types of quantile mapping: quantile mapping, detrended quantile mapping, and quantile delta mapping. The temporal variations of the 12 extreme precipitation indices (EPIs) and 12 extreme temperature indices (ETIs) from 2015 to 2100 consistently suggest drier conditions, in addition to more frequent and severe precipitation extremes and warming temperature extremes in Türkiye, under the two future scenarios. The SSP5-8.5 scenario indicates more severe water stress than the SSP2-4.5 scenario; the total precipitation decreases up to 20% for Aegean and Mediterranean regions of Türkiye. Precipitation extremes indicate a decrease in the frequency of heavy rains but an increase in very heavy rains and also an increasing amount of the total precipitation from very heavy rain days. Temperature extremes such as the coldest, warmest, and mean daily maximum temperature are expected to increase across all regions of Türkiye, indicating warming conditions by up to 7.5 °C by the end of the century. Additionally, the coldest daily maximums also exhibit higher variability to climate change in the subregions Aegean, Southeastern Anatolia, Marmara, and Mediterranean regions of Türkiye while the mean daily maximum temperature showed greater sensitivity in the Black Sea, Central Anatolia, and Eastern Anatolia regions.

The Impact of Climate Change on Construction Activity Performance

“…It is projected that climate change will be one of these major risks and exacerbate the adverse weather or extreme weather impacts by altering the magnitude and/or frequency of the events. Gumus et al [43] have reported that there is an increasing trend in the frequency and intensity of extreme rainfall events. Similarly, there is an expected increase in the frequency of temperature extremes, such as the coldest, warmest, and mean daily maximum temperature, across all regions of Türkiye.…”

“…When the historical and future performance of Formwork (F) activity for January 30th are compared, the increasing workability values can be seen, especially for the coastal, eastern, and southeastern regions (Figure 3c,d). It is also possible to say that the dominant impact factor of the activity for the selected day is Tmax0 • C since an increasing minimum temperature is prominent in the future for the entirety of Türkiye [43]. Similar to Earthworks, summer workability is stationary (Figure 4c,d).…”

“…The reason for these advancements includes determining the amount of natural or human-induced irradiation, the inclusion of aerosols, and land use effects [45,[49][50][51]. Although the CMIP6 data are relatively new, there appears to be a growing interest in implementing the most recent projections [43,48,52].…”

“…For this reason, downscaling and bias correction techniques have arisen in recent years to obtain data for regional and local impact studies. There are many downscaling methods that can be encountered in the literature; however, in this study, quantile delta mapping (QDM), which has proven to exhibit better performance with extremes [43,53], is used.…”

“…The biggest difference from the original is that the horizontal resolution is presented as 0.10 • × 0.10 • instead of 0.25 • × 0.25 • . This difference makes it possible to operate on more precise scales [43]. This dataset is utilized in this study as a reference to downscale the CMIP6 global climate model projections and to determine the performance of bias-corrected and downscaled data.…”