Long-term annual climate trends around the Breton Plots area, Alberta: is there any evidence of local climate change?

Abstract

The objective of this research was to investigate the long-term trends in historical climate variables using the data collected near the classical Breton Plots (Alberta, Canada) and to determine if the data show any evidence of local climate change. The climate data used for the study were obtained from the Alberta Climate Information Service for the years 1901–2020. Various parametric statistical analyses were conducted to determine if monotonic trends occurred in the climate variables over time, and the analyses were conducted on the annual data as well as the 30 year climate normals. Large fluctuations in annual climate variables occurred, but a positive linear trend was observed in the average annual and growing season minimum air temperatures over time. Between 1901 and 2020 the annual minimum air temperature average increased at a rate of 0.3 °C for every 10 years. During the winter periods (December, January, and February, inclusive) from 1901 to 2020, the minimum air temperature average increased at an even higher rate of 0.5 °C every 10 years. Overall, the 30 year climate normals for minimum and maximum air temperatures increased for most seasons. The rates of increase were largest over the winter period, at 0.5 °C every 10 years for minimum air temperature and at 0.3 °C every 10 years for maximum air temperature. Strong linear increases occurred over time for growing degree days, number of frost-free days, total annual precipitation, growing season precipitation, and off-season precipitation.