Carpathian Journal of Earth and Environmental Sciences

We use temperature-humidity index (THI) and the Net Effective Temperature (NET) index to estimate the occurrence of thermal stressful conditions during summer in Romania under the RCP 4.5 and RCP 8.5 climate change scenarios. We employ results from four regional climate models for the periods 2021-2050 and 2071-2100, obtained within EURO-CORDEX initiative. The reference interval is 1971-2000 and we use a high-resolution (0.1° x 0.1°) dataset for Romania to validate the modelled historical runs. The indices are computed using daily values of maximum air temperature, relative humidity and wind speed at 10 m. The results show that the ensemble mean of historical runs captures well the spatial patterns of THI and NET, but their magnitudes are significantly underestimated due to underestimation of maximum air temperature and relative humidity over Romania. As expected, there is an increase in the number of days with thermal discomfort expressed by both indices, which is larger towards the end of this century, under the RCP 8.5 scenario. The largest increase in the number of warm episodes associated with discomfort conditions is found for the Western and Southern parts of Romania.