Key Takeaways:
- Human-caused global heating made the intense heatwave in Australia in early January five times more likely
- The heatwave was the most severe since the 2019-20 black summer, with temperatures over 40C in Melbourne and Sydney
- The climate crisis made the extreme heat about 1.6C hotter, while the La Niña likely lowered maximum temperatures by between 0.3 and 0.5C
- Heatwaves cause more deaths in Australia than all other natural hazards combined
- Australians can expect heatwaves similar to the January event about once every five years, with similar heat events expected every second year if the world warms 2.6C above the preindustrial average
Introduction to the Heatwave
The recent heatwave that affected much of Australia in early January was a severe and devastating event, with temperatures soaring over 40C in Melbourne and Sydney, and even hotter conditions in regional Victoria and New South Wales. The heatwave was the most severe since the 2019-20 black summer, and it had a significant impact on the country, with bushfires burning through 400,000 hectares and destroying almost 900 buildings in Victoria. A new analysis by World Weather Attribution (WWA) suggests that human-caused global heating made the intense heatwave five times more likely, highlighting the significant role that climate change is playing in extreme weather events.
The Role of Climate Change
The report by WWA suggests that the effect of greenhouse gas emissions outweighed the effects of a weak La Niña, which usually means milder temperatures across most of mainland Australia. The report’s authors found that the climate crisis made the extreme heat about 1.6C hotter, while the La Niña likely lowered maximum temperatures by between 0.3 and 0.5C. This highlights the significant impact that climate change is having on extreme weather events, and the need for urgent action to reduce greenhouse gas emissions. According to Prof Sarah Perkins-Kirkpatrick, a climate scientist at the Australian National University and co-author of the report, "There was definitely a signal of human-induced climate change behind this event."
The Impact of Heatwaves
Heatwaves are a significant threat to human health, particularly in Australia, where they cause more deaths than all other natural hazards combined. The effects of heatwaves can be insidious, with people often not realizing the impact of the heat until days after the event. This can lead to a range of health problems, including the exacerbation of underlying diseases. As Perkins-Kirkpatrick noted, "When people are affected by extreme heat, it is very insidious… it’s something that comes to light in a number of days after the event, and may also be due to the exacerbation of underlying diseases." The "mentality here of ‘suck it up, she’ll be right’ does not fly any more," she said, highlighting the need for people to take the threat of heatwaves seriously.
The Future of Heatwaves
The analysis suggests that Australians can expect heatwaves similar to the January event about once every five years, with similar heat events expected every second year if the world warms 2.6C above the preindustrial average. This is a sobering prospect, and highlights the need for urgent action to reduce greenhouse gas emissions and mitigate the impacts of climate change. As WWA co-founder Friederike Otto noted, "As extreme heat is one of the deadliest extreme weather events that is changing very fast with global warming… it is important to highlight these rapid changes, even if the results are not surprising at all." The techniques used by WWA to analyze the role of human-caused global heating in extreme weather events are well established, but the results of the study are not yet peer-reviewed.
Conclusion
In conclusion, the recent heatwave in Australia was a significant event that highlights the impact of climate change on extreme weather events. The analysis by WWA suggests that human-caused global heating made the intense heatwave five times more likely, and that the climate crisis made the extreme heat about 1.6C hotter. The effects of heatwaves can be devastating, and it is essential that people take the threat of heatwaves seriously. As the world continues to warm, Australians can expect heatwaves similar to the January event to become more frequent, highlighting the need for urgent action to reduce greenhouse gas emissions and mitigate the impacts of climate change.
