What is climate change?

People holding signs during protest

“Climate change” describes a change in the average conditions — such as temperature and rainfall — in a region over a long period of time. Earth’s climate is always changing over long periods of time and has been hotter and cooler than it is now, but the pace of change has sped up significantly in recent decades. Scientists are deeply concerned about the changes they’ve observed since the Industrial Revolution.

Human-caused climate change is affecting the planet in ways that could alter all life on Earth. It’s the biggest, most urgent problem we face. In fact, many — including the David Suzuki Foundation — have started using stronger terms such as climate emergency, climate crisis, climate disruption and climate chaos to reflect the severity.

Why does climate change happen?

Carbon is stored all over the planet — in plants, soil, oceans, Earth’s crust, even in us. We release carbon into the atmosphere as carbon dioxide through activities such as burning fossil fuels (coal, oil and gas) and cutting down trees and destroying wetlands. That carbon dioxide builds up in the atmosphere, along with other greenhouse gas emissions, creating a “greenhouse effect,” whereby energy from the sun gets trapped and Earth’s temperature rises. Today, the atmosphere contains 42 per cent more carbon dioxide than it did before the Industrial Revolution.

Why should we care about climate change? 

In 2018, the Intergovernmental Panel on Climate Change published a special report explaining the effects of a warming world. The news is not good. According to IPCC scientists, to avoid the worse impacts of heating — including more severe and frequent wildfires, droughts, floods and species extinction — we must keep the global average temperature from rising more than 1.5 C above pre-industrial levels. A rise of even half a degree more could result in significantly more severe heatwaves, plant and animal species lost to extinction and devastating storms and floods.

Climate disruption puts human life at risk worldwide. Our health, food systems, economies and communities are all at enormous risk. But climate change poses the greatest threat to those least responsible for it — people who are already vulnerable to socio-economic challenges, such as poor communities, communities of colour, women and youth.

We should care about climate change because we’re already experiencing its devastating effects. And we’re seeing warming greater than the global average on land and in waters. With that has come an increase in severity and frequency of storms, heat waves, wildfires and heavy rains. These negative effects will worsen as the level of carbon pollution in our atmosphere continues to rise.

We used to think of climate change as a problem looming in our future, but we know now with certainty that it’s here.

What we can do about climate change?

Broadly speaking, we need to focus on two things to address climate change: mitigation and adaptation.

To mitigate climate change, or avoid the worst consequences of a warming world, we must reduce the concentration of greenhouse gases in the atmosphere. That means reducing emissions. If we want to limit warming to 1.5 C, we must cut global emissions by half by 2030 and reach net-zero (when there’s a balance between emissions produced and emissions removed from the atmosphere) by 2050.

Burning fossil fuels like coal, oil and natural gas is the largest source of emissions, so we need to stop extracting and burning these resources. We can do this by conserving energy and by choosing clean electricity over fossil fuels. We can also reduce emissions in the atmosphere through nature-based climate solutions like planting trees and restoring wetlands and forest ecosystems.

Because the climate is already changing, we also need to adapt. This involves preparing for the effects of climate change, including extreme weather events, sea level rise and food insecurity. Each region, city or town will require different solutions for adaptation, which is why municipalities are leading this work.

Is it too late to stop climate change?

Although the climate is already changing, it’s not too late to avoid the worst of it. The good news is that the technical and policy solutions to climate change already exist, and the costs of renewable and clean technologies have fallen dramatically. There’s also a lot of room for energy conservation, especially in countries like Canada and the United States that use excessive amounts of energy. What’s lacking is political will. We need to hold our leaders accountable for taking bold action on climate change. We need to demand a healthy, sustainable future so everyone can thrive.

Do you want to find out how you can take action on climate change in your life? Check out our list of the top 10 things you can do about climate change.