Impact of climate change on temperature and precipitation in Toruń, Poland, based on CMIP6 under SSP scenarios

The latest projection of temperature under Shared Socioeconomic Pathways (SSPs) scenarios from Coupled Model Intercomparison Project Phase-6 (CMIP6) indicates that, by the 21st century, the global average temperature will increase by over 5.4 °C in the highest-emission scenario and 1.1 °C in the highest mitigation scenario. Climate change is mainly described by changes in two main meteorological variables, i.e., temperature and precipitation. Observed and projected changes in temperature and precipitation significantly influence various hydroclimatic events such as droughts and floods. Therefore, a precise projection of those variables, including at local and regional scales, is crucial and urgently needed. In Poland, the negative impact of the observed warming on the frequency and intensity of droughts and floods has been detected.

In this research, we present a projection of temperature and precipitation variations in Toruń, Poland, for future periods (2015–2100). To accomplish this, several general circulation models (GCMs) are employed under two SSP scenarios, namely SSP1-2.6 and SSP5-8.5 from NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6) datasets. In these models, the historical reference period is 1950–2014, and future projections are for 2015–2100.

The results indicated that the mean annual air temperature will increase from 8.1 °C in the reference period to 8.9 °C in SSP1-2.6 scenario and 10.1 °C in SSP5-8.5 scenario. Precipitation will increase slightly under both scenarios. It is projected that the average annual precipitation in Toruń will change from 514.38 mm in the reference period to 533.15 mm and 522.37 mm during 2015–2100 according to the SSP1-2.6 and SSP5-8.5 scenarios, respectively. It is evident that an increase in precipitation and heavy rainfall will culminate in extreme occurrences such as floods, which will further threaten lives, properties and the environment within the heart of Toruń.