July 7, 2017
Climate Trends and Future Projections in the Region of Peel
The purpose of this study is to characterize recent climate trends and future projections across an array of climate indicators of interest to Region of Peel’s stakeholders.
Warming of Earth’s climate system is unequivocal. Historical observations demonstrate that the atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. Future global surface temperature change for the end of the 21st century is likely to exceed 2°C relative to 1850 to 1900 assuming business-as-usual emissions continue. This translates to increasingly frequent and more extreme weather events in the future, such as extreme heat days (virtually certain), heat waves (very likely), and heavy rainfall events (likely) over many areas of the globe (IPCC, 2013).
The Region of Peel needs to be prepared, in part by understanding its regional climate conditions. The purpose of this study is to characterize recent climate trends and future projections across an array of climate indicators of interest to Region of Peel’s stakeholders. Meant to serve as the foundation for a variety of sectoral vulnerability assessments, this study emerged out of Peel’s Climate Change Strategy in 2011.
This study uses state-of-the-science climate modeling recommended by the Intergovernmental Panel on Climate Change (IPCC). The ensemble of global climate models used in the most recent IPCC assessment is used to obtain the future climate conditions for the period of 2011 – 2100 (“future periods”). Each variable is modeled for the future periods and presented as 2020s (short term), 2050s (medium term), and 2080s (long term) projections.
Historical observations are also obtained for the baseline period (1981-2010) to examine to what extent Peel’s historical climate is projected to change into the future. Future emissions scenarios, or Representative Concentration Pathways (RCPs), are provided to tell the potential range of Peel’s future climate conditions. RCP4.5 illustrates a moderate radiative forcing (less extreme) future whereas RCP8.5 illustrates a high radiative forcing (more extreme) business-as-usual future which global greenhouse gas concentrations are currently following.
While data were analysed out to 2100 for both RCP scenarios, this summary will focus on the RCP8.5 scenario and provide more details on the 2050s planning horizon, which was selected based on corresponding work on vulnerabilities in the Region of Peel.
There are a few recommendations that were developed through this report, including:
- Work with climate and subject matter experts to continually liaise and update this work as new climate model projections become available to contribute better information towards adaptation planning and similar initiatives in the Region of Peel.
- Be conservative when estimating risk with the climate information contained in this report.
- Continue understanding and addressing the impacts of climate change, such as bolstering higher resolution and long term monitoring programs to support better adaptive management and planning.
The development of this report was made possible with funding from the Region of Peel.