Tropical Toronto: Deep Dive

Climate change is affecting us where we live and is affecting us now. The most vivid images of climate change include melting glaciers, mass deforestation and rising sea levels, But in the urban context, this will look like more flooded basements, the spread of disease, weakening civic infrastructure, food scarcity and human migration – all realities for communities across Ontario. 

The number of very hot days in Toronto (where the daily temperature goes above 30°C) has rapidly increased, and over the next decade, Toronto will see the number of very hot days increase 3-fold from the historical average1. Ontario has the longest freshwater coastline in the world2 and its borders run through four of the five Great Lakes and part of the St. Lawrence River. These rising temperatures are also directly leading to overheating of the Great Lakes. In the summers, Lake Ontario’s average temperature now consistently hits 25 degrees Celsius (previous “normal” was around 18 degrees Celsius)3. Nobody is immune from the impacts of climate change – the Anthropocene is here. Now!

What does all this mean for Ontarians?

In summer, the electrical grid will continue to be tested by more air conditioning, potentially leading to brown-outs or black-outs on the hottest days. Flooding in urban areas will get more intense, and more localized rainstorms will continue. In communities across Northern Ontario, melting permafrost will have a disastrous effect on infrastructure, forcing entire communities to move as buildings and roads sink into a newly porous landscape. Another terrifying effect of melting permafrost is that containment ponds will leach toxic mining waste into the surrounding earth and water as their walls and foundations disintegrate, potentially contaminating the entire food chain. Even food that isn’t affected by permafrost melt will have increased variability and lengthening of the growing season caused by a changing climate, which will have severe impacts on the agricultural sector, affecting planning for types of crops, new crop pests, weeds and plant diseases.4

Photo by Justin Ziadeh

Rising temperatures will also mean that many Ontarians will experience a range of healthcare challenges5We can expect to see an increased incidence of heat-related illness and respiratory and cardiovascular disorders due to rising temperatures and reduced air quality. Certain diseases transmitted by mosquitoes, ticks and other vectors will increase due to rising summer temperatures (e.g., Lyme disease, West Nile virus). As is always the case with disasters, increased vulnerability to heat waves will be faced by groups who are most marginalized.

What can you do?

While we are increasingly conscious of our personal environmental footprints, the reality is that the scale of change needed requires action at a systemic level. There are multiple organizations on the ground across the province that are actively engaging scientists, activists, policymakers and industries. 

To learn more about organizations across Toronto and Ontario at the frontline of fighting local climate change, please visit the TCAN website

  1. Climate Data Canada. (n.d.). Toronto, ON. Retrieved Aug 05, 2020, from Climate Data Canada:
  2. Ontario’s Great Lakes Strategy. (2019, May 29). Retrieved Aug 06, 2020, from
  3. Samenow, J. (2020, Jul 14). The Washington Post. Retrieved from The Washington Post:
  4. Metzger , P. (2017, Nov 14). What climate change has in store for Ontario. Retrieved from The Ontario Educational Communications Authority (TVO):
  5. Gough, W., Anderson, V., & Herod, K. (2016). ONTARIO CLIMATE CHANGE AND HEALTH MODELLING STUDY. Toronto: Ministry of Health and Long-Term Care Public Health Policy and Programs Branch.