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.

a view of the Lake Ontario waterfront and Toronto skyline at sunset

“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:

Temperature
Since the 1980s, each decade has been warmer than the last. For those who were born in the last 10 years, their lives have been marked by the world’s warmest years on record.
 
 
 
 
precipitation
Warmer air can hold more water and increase evaporation to create heavier storms. With rising temperatures, wetter regions have generally seen more precipitation, while drier regions have seen less.
 
 
 
 
hot and cold extremes due to climate change
Extreme heat events are becoming more frequent and intense, putting more people at risk of heat-related illnesses and death, especially seniors and young children, people with pre-existing conditions or limited access to cooling, and people who must spend long hours outdoors. Meanwhile, cold weather days are becoming less frequent as winters get warmer.
 

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.

an infographic depicting the potential impacts of climate change on the Toronto region

TEMPERATURE

temperature stripes banner for the Greater Toronto region from 1849 to 2023

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.

IPCC Projections: Global
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
TRCA Projections: Local
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.
How Does This Affect Us?
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

precipitation stripes banner for the Greater Toronto region from 1849 to 2023

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.

IPCC Projections: Global
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

 
 

TRCA Projections: Local
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
How Does This Affect Us?
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

IPCC Projections: Global
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.

 
 
 

TRCA Projections: Local
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.
How Does This Affect Us?
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:

species at risk in Toronto region due to climate change
Risk of local species loss (e.g., Jefferson Salamanders)
increase in diseases in Toronto region due to climate change
Increase in vector-borne diseases (e.g., Lyme disease)
mass mortality of plant and animal species in Toronto region due to climate change
Loss of native plants and animals
flooding in Toronto region due to climate change
Increased intensity and frequency of flooding and erosion
hikers explore wilderness trail at Kortright Centre for Conservation
Declining ecosystem services (i.e., the benefits nature provides to humans)
 
invasive phragmites
Introduction of non-native species (e.g., phragmites) that can outcompete native wildlife and plants
TRCA team finds baby snapping turtle on the shoulder of a busy road
Changes to species range and interactions, habitat suitability, and connectivity
patient receives treatment in hospital
Direct and indirect impacts on people’s health, including mental health

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:

CLIMATE SCIENCE
ADAPTATION
MITIGATION

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:

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.

DOWNLOAD THE FACTSHEET

Climate Change in Your Community fact sheet

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.

IPCC Climate Change 2023 - Synthesis Report

IPCC 2021 climate change report on physical science

IPCC 2022 climate change report on impacts adaptation and vulnerability

IPCC 2022 climate change report on mitigation

Canadian Climate Change Resources


QUESTIONS?

Please contact TRCA’s Watershed Planning and Ecosystem Science team:
wpes@trca.ca