UC Irvine

A combination of climate events (e.g., low precipitation and high temperatures) may cause a significant impact on the ecosystem and society, though individual events involved may not be severe extremes themselves. Analyzing historical changes in concurrent climate extremes is critical to preparing for and mitigating the negative effects of climatic change and variability. This study focuses on the changes in concurrences of heatwaves and droughts from 1960 - 2010. Despite hiatus in rising temperature and no significant trend in drought, we show a substantial increase in concurrent droughts and heatwaves across most parts of the United States, and a statistically significant shift in the distribution of concurrent extremes. While the commonly used trend analysis methods do not show any trend in the data, a unique statistical approach, outlined in this study, exhibits statistically significant change point in the distribution of concurrent droughts and heatwaves.