Taking Action on Climate Change in Toronto Region
On This Page We Explore:
1. How climate change is affecting life on Earth. READ MORE.
2. What these changes mean for Toronto and Region. READ MORE.
3. What Toronto and Region Conservation Authority (TRCA) is doing to combat climate change. READ MORE.
4. What you can do to take action. READ MORE.
5. Resources to learn more. READ MORE.
“Every action matters. Every bit of warming matters. Every year matters. Every choice matters.”
— Intergovernmental Panel on Climate Change (IPCC), 2022
1. HOW CLIMATE CHANGE IS AFFECTING LIFE ON EARTH
Human-caused climate change is putting people, ecosystems, and the economy at increasing risk. Here are some examples of how the climate is changing:



The more heat-trapping greenhouse gases (GHGs) we continue to emit, the more global temperatures will continue to rise. Global temperatures have already increased at an alarming rate, leading to more record-breaking temperatures and extreme weather events around the world, including here at home.
The scientific community has issued a code red for humanity. The time for action is now: We must work together to limit warming to below 2°C, and ideally to 1.5°C, by cutting global GHG emissions in half by 2030 and reaching net-zero carbon dioxide (CO2) emissions by 2050.
Global temperatures will stabilize when CO2 emissions reach net zero. More devastating impacts can still be avoided, while we continue to adapt to the shocks and stresses that are already being felt. Through rapid and sustained actions, we can create a safer, cleaner, and healthier world for those who are alive today and future generations.
CLIMATE CHANGE IMPACTS: Quick Facts
The summer of 2024 was the world’s hottest on record.
The June and August 2024 heatwaves in eastern Ontario were made much more likely by climate change.
Canada’s 2023 wildfire season was the most destructive on record, while 2024 ranked among the worst in terms of area burned since 1995.
The Toronto region experienced several major storms in the summer of 2024 that exceeded the 1 in 100-year storm, which has a 1% chance of occurring in any year.
2. HOW CLIMATE CHANGE IMPACTS OUR REGION
These changes are being felt locally in TRCA’s jurisdiction – especially flooding, erosion, and extreme heat. These impacts will worsen if GHG emissions continue to climb, leading to higher levels of global warming.
TEMPERATURE
In this temperature stripes banner, 175 years of temperature data captured in the Toronto region, from 1849 (left) to 2023 (right). Each bar shows the difference in annual average temperature for each year compared to the average temperature over the 20th century (1901-2000). Warmer than average years are represented by red stripes and cooler years are represented by blue stripes. The darker the stripe colour, the greater the difference from the 20th century average.
Increased global surface temperature by the end of the century (2081-2100), compared to the pre-industrial period (1850–1900). Likely ranges include:
- 2.1°C to 3.5°C warmer under the intermediate GHG emissions scenario
- 3.3°C to 5.7°C warmer under the very high GHG emissions scenario
Temperatures in the Toronto region are also projected to increase by the end of the century:
- Mean annual temperatures may increase from 7.3°C (1971-2000) to a projected range of 9.8°C to 15.8°C under the high emissions scenario.
- Temperatures are projected to increase across all seasons throughout the year.
Changes in temperature affect agriculture, infrastructure, people’s health, water availability, energy use, recreation, and ecosystem health.
While the difference may seem small, every additional increase in average temperature can lead to more extreme weather events.
PRECIPITATION
In this precipitation stripes banner, we show 175 years of precipitation data captured in the Toronto region, from 1849 (left) to 2023 (right). Each bar shows the difference in average annual total precipitation for each year compared to the average precipitation over the 20th century (1901-2000). Wetter than average conditions are represented by green stripes and drier than average conditions are represented by brown stripes. The darker the stripe colour, the greater the difference from the 20th century average.
Increases in global average precipitation will result in:
- Altered water cycle, as rates of change in average
- Substantial regional and seasonal differences in rain and snow as wet regions generally get wetter and dry regions generally get drier
Precipitation is expected to increase in the Toronto region by the end of the century:
- Total annual precipitation may increase from 986 mm (1971-2000) to a projected range of 1,015 to 1,292 mm under the high emissions scenario
- More frequent and intense storms are expected to occur, with total precipitation falling in one day increasing from 29.4 mm (1971-2000) to 47 to 59.5 mm under the high emissions scenario
Changes in precipitation affect agriculture, infrastructure, people’s health, water availability, recreation, and ecosystem health.
An increase in average and extreme precipitation can increase the risk of flooding and erosion, placing people, property, and infrastructure at greater risk. These impacts are often unequally distributed, affecting some people more than others – including people who face multiple, overlapping stressors due to systemic and long-standing inequities.
HOT AND COLD EXTREMES
Hot and cold extremes are expected to continually change with global warming:
- Hot extremes are expected to increase in frequency and
- Extreme heat events that used to have a one in 10 chance of occurring each year are expected to be 8.3 to 9.6 times more likely to occur under the very high emissions scenario.
Hot and cold extremes in our region are projected to change in response to global warming:
- The number of very hot days above 30°C and 35°C are expected to increase from around 11 days and 1 day (1971-2000), respectively, to 52 days and 14 days, respectively, under a high emissions scenario.
- The number of very cold days below -20°C is expected to decrease from around 10 days (1971-2000) to nearly zero days under a high emissions scenario.
Extreme heat and extreme cold put everyone’s health at risk, especially seniors, young children, people with pre-existing conditions, people with limited access to cooling/heating, and people who must spend long hours outdoors.
They can pose a risk to our built infrastructure such as buildings, transportation systems, and energy systems, depending on their design parameters. They also pose a threat to plants and animals that are not adapted to the heat/cold or require stable temperature conditions.
Visit TRCA’s Watershed Reporting Hub to view climate projections in the Toronto region.
Ecosystem Changes in Toronto and Region
Climate change has altered marine, terrestrial, and freshwater ecosystems worldwide. Many ecosystems and species are unable to adapt to these rapid changes. Here are a few examples of ecosystem changes TRCA has observed in the Toronto region:








3. WHAT IS TRCA DOING TO COMBAT CLIMATE CHANGE?
TRCA collaborates with practitioners across various municipalities and other conservation authorities to deliver programs and initiatives geared towards the following:
- Toronto’s Current and Future Climate Report (2024)
- Climate Change in the Great Lakes Basin: Summary of Trends and Impacts (2022)
- Climate Change in the Great Lakes – Video
- Durham Region – Climate Trends
- Durham Region – Climate Impacts
- Guide to Conducting a Climate Change Analysis: Lessons Learned from Durham Region (2021)
- The State of Climate Modeling in the Great Lakes Basin (2020)
- Scan of International Climate Information Platforms (2018)
- Climate Trends and Future Projections in the Region of Peel (2016)
- Historical and Future Climate Trends in York Region (2016)
- Health Benefits of Urban Trees Infographic (2024)
- How Trees Protect People’s Health from Extreme Heat (2024)
- Nature-Based Climate Solutions (NBCS) Siting Tool: Phase 2 (2024)
- Nature-Based Climate Solutions (NBCS) Siting Tool: Phase 1 Pilot Study Report (2022)
- Asset Management Ontario’s Climate Change & Green Infrastructure Course
- Baseline Coastal Habitat Survey Webinar Series (2023)
- Great Lakes Coastal Wetlands Webinar Series and StoryMap (2022)
- Integrating Climate Change into Durham’s Policies and Plans (2018)
- Natural Systems Vulnerability to Climate Change in Peel Region (2017)
- Climate Change Effects on Agricultural Production in the Region of Peel (2016)
- Climate Change Vulnerabilities of Community Services and Assets in the Region of Peel: A Case Study in Port Credit (2016)
- Assessing and Mitigating Municipal Climate Risks and Vulnerabilities in York Region, Ontario (2016)
- Ontario Climate Consortium Proceedings (2013-2018)
Municipal Climate Strategies and Action Plans
Municipalities across the region have developed strategies and action plans for climate change adaptation and mitigation in their communities. These include:
City of Toronto: | Resilience Strategy |
TransformTO Net Zero Strategy | |
Region of Peel: | Climate Change Master Plan |
Durham Region: | Durham Community Climate Adaptation Plan |
York Region: | Climate Change Action Plan |
4. WHAT YOU CAN DO TO TAKE ACTION
Climate Change in Your Community Factsheet
This TRCA resource spotlights the local impacts of climate change and suggests a variety of actions you can take in your own community – from stormwater landscaping projects, to reducing household waste, to choosing more sustainable forms of transportation.
Climate Action Calendar
VISIT THE TRCA CALENDAR FOR MORE COMMUNITY EVENTS
5. MORE RESOURCES
IPCC Working Group Reports
The Intergovernmental Panel on Climate Change‘s Sixth Assessment Report highlights the devastating consequences resulting from higher levels of global warming. The IPCC is the United Nations body responsible for assessing the science related to climate change, its impacts and potential future risks, and options to address climate change.
Canadian Climate Change Resources
QUESTIONS?
Please contact TRCA’s Watershed Planning and Ecosystem Science team:
wpes@trca.ca