Spatio-temporal analysis of heating and cooling degree-days over Iran

In this research, temporal trends and change points in heating degree-days (HDD), cooling degree-days (CDD), and their simultaneous combination (HDD + CDD) were analysed for a 60-year period (1960-2019) in Iran. The results show that less than 20% of the study stations had significant trends (either upward or downward) in HDD time series, while more than 80% of the stations had significant increasing trends in CDD and HDD + CDD time series. Abrupt changes in HDD time series mostly occurred in the early 1980s, but those in CDD time series were mostly observed in the 1990s. The cooling energy demand in Iran has dramatically increased as CDD values have raised up from 690 oC-days to 1010 oC-days in the last 60 years. HDD, however, almost remained constant in the same period. The results suggest that if global warming continues with the current pace, cooling energy demand in the residential sector will considerably increase in the future, calling for a change in residential energy consumption policies.

Automated summary

Less than 20% of study stations showed significant trends in HDD, while over 80% had significant increasing trends in CDD and HDD + CDD. Cooling energy demand in Iran has dramatically increased in the last 60 years, while heating energy demand has remained relatively constant. Results suggest that if global warming continues, there will be a considerable increase in cooling energy demand in residential sectors.