In recent years, Australia has experienced both extreme flooding and record-low rainfall, prompting researchers from the Chinese Academy of Sciences to investigate the causes behind this unpredictable weather pattern. Their study reveals that human-induced climate warming is significantly increasing rainfall variability across 75% of the Earth’s land, with Australia being notably affected.
The research indicates that the rise in rainfall variability results in wetter wet periods and drier dry periods. Globally, daily rainfall variability has increased by 1.2% per decade, primarily due to anthropogenic greenhouse gas emissions, which have led to a warmer and more humid atmosphere.
This additional moisture in the air causes more intense rain events and larger fluctuations between them, even without changes in atmospheric circulation.
Experts like Professor Steven Sherwood from the UNSW Climate Change Research Centre, who was not involved in the study, underscore the implications of these findings. He notes that as global warming continues, the likelihood of experiencing severe droughts and floods will rise.
The study identifies Australia as a hotspot for this increased rainfall variability, with southeast Australia already experiencing such changes as global warming progresses.
However, some experts, like Dr. Tom Beer, are skeptical about the extent of Australia’s unique impact. He points out that the study acknowledges the weaker signal over Australia for the period between 1950 and 2020 due to significant internal variability. This suggests that while the trend is evident, the data over a shorter timeframe may not fully capture the long-term impact.
The study’s lead author, Dr. Zhou Tianjun, warns that the anticipated future of increased precipitation variability is already a present reality. This heightened variability complicates the ability to predict and prepare for environmental impacts, underscoring the urgent need for adaptive strategies in the face of ongoing climate change.