Understanding Climate Change’s Impact on Extreme Weather

Canadian scientists, led by B.C.-based atmospheric physicist Nathan Gillett from Environment and Climate Change Canada, have developed a rapid event attribution system that can estimate how much human-induced climate change contributed to extreme weather events, such as heat waves or floods, within a week. This system utilizes past data to determine the likelihood that climate change increased the probability of such events. Gillett highlights that while it can’t pinpoint climate change as the sole cause of any specific event, it can show how climate change has increased the odds of such occurrences.
The team is currently piloting this system and analyzing recent extreme weather events, including a significant heat dome in central Canada. They aim to establish criteria for public rapid analyses based on factors like temperature and duration of heat waves.
This new capability is expected to aid public understanding of climate change effects and assist policymakers in climate adaptation planning. For instance, a 2021 report indicated that climate change made B.C.’s heat dome 150 times more likely, with such events potentially recurring every five to ten years even if greenhouse-gas reduction targets are met.
Additionally, climate change has led to more frequent, intense, and prolonged heat waves, occurring not just in summer but also in spring, necessitating adaptation. Extreme heat waves pose serious health risks, such as heat exhaustion and heat stroke, particularly when coupled with high humidity that prevents nighttime cooling. Recent reports have highlighted deadly heat waves across the globe, including over 500 heat-related deaths during the Hajj pilgrimage in Mecca and extreme heat advisories affecting nearly 100 million Americans.