Climate Change Impacts

Rising global temperatures are expected to impact the frequency and severity of extreme weather events — with implications that will be felt at both the local and the global level.



Buildings are susceptible to storm damage, particularly during heavy rainfalls that overwhelm stormwater systems and extreme winds that damage buildings and infrastructure. The milder winters within the GTA are already proving troublesome by causing more freeze-thaw cycles that accelerate wear on roads and buildings.

Toronto Climate Change impacts


Energy, especially electricity, will be affected in three main areas; generation and production: transmission and distribution; and energy demand. The capacity of nuclear and coal generating stations is expected to decrease as warmer water temperatures reduce the efficiency of the condensers. With energy demand increasing, occurrence of brownouts and blackouts is expected.

Financial Burden on Municipalities

Extreme weather and natural disasters can place a huge financial burden on municipalities. Costly clean up effort and repairs to infrastructure will become more common. For example, the July 2013 storm that caused flash flooding across the GTA resulted in more than $850 million in property damages, making it the most expensive natural disaster in the province’s history.

Toronto climate change local impacts

Human Health

Warmer summers and increasing levels of air pollution are already affecting the health of the people living in the GTA. Also, a warmer climate will spread vector-borne disease, as northern limit of many disease carriers is controlled by temperature. West Nile Virus for instance, was not present in Toronto in early 2000. Warmer weather is also expected to increase the risk of water and foodborne diseases as well.


Households that live below the poverty line are more prone to the impacts of climate change as they have fewer resources to protect themselves from extreme weather or natural disasters. Recovery from disaster is also more difficult for low-income households that may have limited or no insurance coverage or savings.

Tourism & Recreation

Tourism and recreation that boost the GTA economy may be impacted negatively by climate change indications such as poor air quality or the threat of infectious diseases.

Toronto climate change local impacts


All forms of mobility are already subject to weather related service disruptions, which threaten to become more frequent as weather patterns become more erratic and severe. For example, public transit operations are most vulnerable to blackouts, which leave electricity dependent trains and streetcars stranded. Road travel is also affected by the loss of power to traffic lights.

Toronto climate change impacts local transportation

Urban Ecosystems

Ecosystems within urbanized areas already face pressure from heat stress and air and water pollution. The urban forest will suffer from the increase in severity and duration of heat waves. The composition of plant and animal species in wetlands will likely change, with native species disappearing and more invasive species moving in. Hotter summers will lead to greater surface water evaporation and may lead to significantly lower water levels in the rivers and waterways within the GTA.


Within the Greater Toronto Area (GTA), water quality, water supply and wastewater infrastructure are likely to be affected by climate change. Heavy downpours cause waste water to enter the rivers and streams, damage infrastructure, erode stream and riverbanks, and flush polluted substances such as oil, lawn fertilizers, and animal waste into waterways. Warmer water temperatures in Lake Ontario may allow new waterborne pathogens to move northward or existing ones to flourish.

Toronto climate change impacts local water




Studies indicate that climate change scenarios include increased frequency of heat stress, droughts and flooding would reduce crop yields and livestock productivity. Climate change also modifies risks of fires, and pest and pathogen outbreaks, with negative consequences for food, fibre and forestry.

Modelling results for a range of sites find that in mid to high latitude regions, moderate local increases in temperatures (1-3 degrees Celsius) along with associated carbon dioxide increase and rainfall changes, can have a small beneficial impact on crop yields. However, in the low latitude regions, even moderate temperature increases (1-2 degrees Celsius) are likely to have negative yield impacts on agriculture.


Human beings are exposed to climate change directly by changing weather patterns such as temperature, precipitation, rise in sea-level and more frequent extreme events. And indirectly through changes in water, air, and food quality as well as changes in ecosystems, agriculture, and economy.

If no further actions are taken to address climate change, the Intergovernmental Panel on Climate Change (IPCC) projects that the health status of millions of people would be affected through: increases in malnutrition; increased deaths, diseases and injury due to extreme weather events; increased frequency of cardio-respiratory disease due to poor air quality; and altered spatial distribution of infectious diseases.

Although climate change would bring some benefits in temperate areas, such as fewer deaths from cold exposure, IPCC expects that negative health effects of rising temperatures, especially in developing countries, would outweigh the benefits.


Adverse effect of climate on freshwater systems aggravate the impacts of other stresses, such as population growth, changing economic activity, land use change, and urbanization.

Globally, water demand will grow in the coming decades, primarily due to population growth and water requirement and for irrigating in warmer temperatures. Also, climate change impacts such as higher water temperatures and increased precipitation intensity are predicted.

Longer periods of low flows and floods will exacerbate many forms of water pollution, that impacts the ecosystem, human health and water system reliability.