Fact Check: "Heatwaves are becoming more common due to human-caused climate change."
What We Know
Heatwaves have shown a significant increase in frequency, duration, and intensity across the United States, particularly in major metropolitan areas. According to the US EPA, the average number of heatwaves per year has risen from two in the 1960s to six in the 2010s and 2020s. Additionally, the average length of these heatwaves has increased, with the average heatwave lasting about four days now, compared to three days in the 1960s. The season for heatwaves has also expanded by approximately 46 days since the 1960s. Furthermore, the intensity of heatwaves has increased, with the average heatwave now being 2.5°F above the local temperature threshold, compared to 2.0°F in the 1960s.
Research indicates that human-caused climate change is accelerating the warming of the planet, with a recent report highlighting that global warming is increasing at a rate of 0.27 degrees Celsius per decade. This warming trend correlates with an increase in extreme weather events, including heatwaves. A study published by CNN supports this, stating that some recent heatwaves would have been "impossible without the temperature boost from global warming" (CNN).
Analysis
The evidence presented by the US EPA is robust, as it is based on long-term data collected from 50 large metropolitan areas across the United States, covering a period from 1961 to 2023. The statistical significance of the trends reported—such as the increase in frequency and duration of heatwaves—adds credibility to the claim that heatwaves are becoming more common due to climate change. The methodology employed by the EPA, which defines heatwaves based on local temperature thresholds, ensures that the data is relevant to specific regions, making the findings more applicable to local contexts.
The New York Times report also provides a credible source of information, citing a growing body of research that indicates an acceleration in global warming and its direct link to human activities. The statement from climate scientist Daniel Swain about the relationship between warming and extreme weather events further reinforces the argument that human-caused climate change is intensifying heatwaves.
In contrast, while the sources used in this fact-check are credible, it is essential to note that some media outlets may have varying levels of bias. However, both the EPA and the cited scientific studies are generally regarded as authoritative in the field of climate science.
Conclusion
The claim that "heatwaves are becoming more common due to human-caused climate change" is True. The evidence from multiple reliable sources indicates a clear trend of increasing heatwave frequency, duration, and intensity, directly correlated with the rise in global temperatures attributed to human activities. The data from the US EPA, along with corroborating reports from reputable news sources, supports this conclusion.
