The past century of human-induced warming has increased rainfall variability over 75 per cent of the Earth’s land area, new research shows. The findings, by Chinese researchers and the UK Met Office, were published overnight in the journal Science. They provide the first systematic observational evidence that climate change is making global rainfall patterns more volatile.

Climate models had predicted this variability would worsen under climate change. But these new findings show rainfall variability has already worsened over the past 100 years. Past studies of the observational record either focused on long-term average rain, which is not systematically changing globally, or rainfall extremes where changes are hard to measure accurately. This study looks solely at variability, which refers to uneven timing and amount of rainfall.