What Is Climate Change?

Over the last 50-100 years, increased industrialization and human activities have begun to affect the earth's natural climate balance.

The Greenhouse Effect. Courtesy of: IPCC WG1, 2007 FAQ 1.3, Fig 1

Our atmosphere is full of invisible gases, some of which are greenhouse gases. Greenhouse gases insulate the Earth. They trap the sun's heat and keep our planet warm enough to sustain life.

Some greenhouse gases do exist naturally, but the burning of fossil fuels by humans has increased the amounts of greenhouse gases, especially carbon dioxide (CO₂) in the atmosphere. This means that more of the sun's heat is being trapped than the Earth actually needs. This effect is known as global warming.

Global warming affects our weather patterns and climate conditions, and we refer to this as climate change.

Climate change is a variation in the long-term weather patterns of temperature and precipitation (typically decades or longer). These patterns can result in a climate that is warmer or colder, wetter or drier. Normally, climate change happens slowly over thousands of years, but because of increased industrialization and associated human activities, the Earth’s climate is rapidly warming.

In Ontario, we can expect average temperatures to rise by as much as 3 to 8 degrees Celsius over the next century. Warmer temperatures may result in milder winters, longer growing seasons and a higher frequency of severe weather events such as record-breaking storms, floods, droughts and heat waves. The expected changes in our climate will have a significant impact on Ontario’s ecosystems, and us and our communities.

Read more about climate change in Ontario PDF 409 Kb

The Ministry of Natural Resources has developed an educational tool to show how Ontario's climate might be very different in the future if we do nothing, compared to how it might be if we all do our part.

Try the Climate Change Mapping Tool.

Climate change impacts our province's natural resources – its forests, water, fish and wildlife. Ecosystems and their associated organisms have adapted to specific climatic conditions over time. As the climate changes, there could be impacts to these ecosystems. Climate change may disrupt or alter an ecosystem and the ecosystem services it provides to our society.

Learn more about the known and potential impacts of climate change on natural resources in Ontario

Check out Hop To It, a website for children of all ages with more information about what you can do to help our climate. It also has games and puzzles!

Explore the MNR Climate Change Research Report Series

Make connections to other sites and resources related to climate change