How Climate Change Made the 2021 Canada Heatwave Deadlier

In 2021, Canada faced a heatwave so intense it broke global records. Scientists used a weather forecast model to figure out how much of this disaster was due to climate change. They looked at three different scenarios: the heatwave as it happened, what it would have been like before industrialization, and what it could be like in the future. The findings were shocking. Even with current climate conditions, there could have been 30% more heat-related deaths than what was actually recorded. Climate change was responsible for 11 to 15% of the deaths during this event, depending on weather patterns. This means that without climate change, fewer people would have died. Looking ahead, the situation gets worse. If the same heatwave happened in the future, the death toll would be even higher, possibly 16 to 31% more. This shows that the impact of climate change on extreme weather events is not just a linear increase but a more complex and dangerous problem. This study is important because it provides a reliable way to attribute health impacts to climate change. This method can be used in decision-making and legal settings to show how climate change is affecting people's lives and health.