Temperature and rainfall trend analysis and climate change scenarios for Pelotas (RS)

Abstract

The city of Pelotas, located in the extreme south of the state of Rio Grande do Sul, suffers from heavy rainfall at certain times of the year. Thus, temperature and precipitation meteorological variables are important for studies of climate change impacts, as they affect the availability of environmental resources. This study aimed to detect changes in temperature and precipitation patterns as indicative of climate change for the Pelotas (RS) region during the 21st century (2006-2099), compared with the climate in the current period (1961-2005), by projecting these variables generated by different climate models based on the RCP 4.5 and RCP 8.5 climate scenarios of the IPCC's fifth report (AR5). Projections indicate an average annual temperature increase of at least 3 ° C by the end of the century for the RCP 4.5 scenario and an increase of up to 4.5 ° C for the RCP 8.5 scenario, as well as a significant increase in accumulated annual precipitation. . Regarding agriculture, the monthly temperature and precipitation cycles show that summer crop months will be less affected by the increase of these variables; However, the possible extremes will appear in the increase of precipitation in the months of October and November, beginning of the crops. It should be noted that temperature anomalies indicated a significant increase mainly towards the end of the century. Noting then that for the RCP 4.5 scenario, considered the optimistic scenario in this paper, the MIROC5 model that presented lower positive anomaly values, indicates an average temperature increase of 0.5°C for F1 (2006-2037), while the others models indicate at least 1°C increase.