Taking Action on Climate Change in Toronto Region

On This Page We Explore:

1. How climate change is affecting our planet. READ MORE.

2. What impacts we can expect within 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 you can use to learn more. READ MORE.

To limit global warming to approximately 1.5 degrees Celsius requires global Greenhouse Gas Emissions to peak before 2025 and be halved by 2030

“Every action matters. Every bit of warming matters. Every year matters. Every choice matters.”
Intergovernmental Panel on Climate Change (IPCC), 2022

Human-caused climate change is putting people, ecosystems, and the economy at risk. Record-breaking temperatures and extreme weather are becoming the new norm, leading to irreversible impacts as natural and human systems are pushed beyond their ability to adapt.

The Intergovernmental Panel on Climate Change’s 2021-22 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 possible response options.

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 greenhouse gas (GHG) emissions in half by 2030, and reaching net-zero by 2050.


Based on an assessment of 14,000 scientific publications, the evidence shows changes in every corner of the world. A few examples:


These changes are being felt locally in TRCA’s jurisdiction – especially extreme heat and flooding. These impacts will worsen if greenhouse gas emissions continue to climb, leading to higher levels of global warming.


IPCC Projections: Global
Increased global surface temperature by the end of the century, compared to the pre-industrial period (1850–1900). Likely ranges:

  • 2.1°C to 3.5°C warmer under the intermediate greenhouse gas (GHG) emissions scenario
  • 3.3°C to 5.7°C warmer under the very high greenhouse gas (GHG) emissions scenario
TRCA Projections: Local
Temperatures 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?
We expect that higher temperatures will lead to:

  • More extreme heat days
  • Earlier snowmelt
  • Longer growing season, which may see an increased risk of pests and diseases affecting plants and agricultural crops
  • Higher potential for flooding and erosion as warmer air holds more water to produce storms


IPCC Projections: Global
Increases in global average precipitation will result in:

  • Altered water cycle, as rates of change in average precipitation and stormwater runoff increase with global warming
  • 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) 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 one-day maximum precipitation increasing from 29.4 mm (1971-2000) to 47 to 59.5 mm in a day under the high emissions scenario
How Does This Affect Us?
We expect that higher precipitation will lead to:

  • An increase in hazardous conditions caused by extreme precipitation, placing people, property, and infrastructure at risk
  • Adverse effects on water quality and aquatic ecosystem health
  • An increase in Lyme Disease and other vector-borne diseases


IPCC Projections: Global
Hot and cold extremes are expected to continually change with global warming:

  • Hot extremes are expected to increase in frequency and intensity, while extreme cold is expected to decrease.
  • 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:

  • Number of extreme heat 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.
  • Number of days below -20°C is expected to decrease from around 10 days (1971-2000) to nearly zero days to 3 days, under a high emissions scenario.
How Does This Affect Us?
An increase in extreme heat days will:

  • Further increase the demand for energy-intensive cooling, which may place a strain on our electrical capacity and cause power outages during summer months
  • Increase heat stroke and heat-related respiratory diseases that can affect our most vulnerable residents, including children, seniors, and those with pre-existing health conditions

Visit TRCA’s Watershed Reporting Hub to view climate projections in the Toronto region.

Ecosystem Changes in Toronto and Region

Climate change has now 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 diseases (e.g., Lyme disease carried by blacklegged ticks)
mass mortality of plant and animal species in Toronto region due to climate change
Mass mortality of plants and animals
flooding in Toronto region due to climate change
Increased intensity and frequency of floods
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 presence, landscape level connections and habitat matrix
patient receives treatment in hospital
Various impacts on human health


TRCA collaborates with practitioners across various municipalities and other conservation authorities to deliver programs and initiatives geared towards the following:


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
Region of Peel: Climate Change Master Plan
Durham Region: Durham Community Climate Adaptation Plan
York Region: Climate Change Action Plan




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 Change in Your Community fact sheet

Climate Action Calendar




IPCC Working Group Reports



Please contact TRCA Watershed Planning and Ecosystem Science: