Climate Change

Learn what climate change is, why it matters, and how society can respond to these changes.

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We are hearing more and more about climate change – that it’s a real and serious issue.

But what is climate change? And why does it matter?

Climate change is defined as a change to average and extreme weather conditions that persists over an extended period of time, typically for decades or longer. The changing climate is causing long-term increases in global temperatures and sea levels, as well as changes in the intensity and frequency of extreme events like storms and wildfires.

97% of climate scientists agree that the climate is warming and that human beings are the cause.

The Earth’s atmosphere works like a blanket that traps heat and keeps the planet warm enough to support life. However, greenhouse gas emissions produced by humans have “thickened” this blanket by adding additional heat trapping gases into the atmosphere. Since the industrial period, increased consumption of natural resources and the burning of fossil fuels (such as coal, oil and natural gas) have increased the emission of these gases and their concentrations in the atmosphere.

The Earth’s climate is now warming at a speed and magnitude that is unlike anything in our planet’s long history.

In Canada, recent and future warming is roughly twice the rate of global warming and northern Canada is warming at more than double the global rate. The impacts of widespread warming are evident in many parts of Canada and are projected to intensify in the future.

The Earth’s climate fluctuates over seasonal and short-term time frames due to natural climate cycles such as El Niño, or to regular cycles in the Sun’s energy output.

To be able to understand climate in any one location, you need at least 30 years of data. This allows you to distinguish between natural fluctuations and climate change – providing a picture of the climate conditions and trends. To learn more, see our article on the importance of using 30 years of data.

It is necessary to respond to climate change in two ways: by reducing our emissions of GHGs and by preparing for changes.

Some interventions can do both; for example, nature-based solutions like restoring wetlands help mitigate emissions and manage the impacts of extreme precipitation.

But it’s important to recognize that even if we were to turn off all emissions right now, some additional amount of warming and change is inevitable. It is vital to plan based not on the past climate conditions, but for the future climate.

ClimateData.ca provides data and information for locations all across Canada, to help prepare for and build resilience to Canada’s changing climate.

For more information on the impacts of climate change in Canada, see Canada’s Changing Climate Report.

For any questions about using climate data and information, please contact the Climate Services Support Desk.