January 2003: Physicist Miles Allen witnessed the River Thames flooding, threatening his home in Oxford, England. He asked, “Why did meteorologists refuse to link this incident to climate change?”

Later that year, climatologist Peter Stott from the British Met Office found himself in Italy during one of Europe’s most severe heatwaves. Instead of enjoying a vacation, he faced temperatures exceeding 40 degrees Celsius, a shocking experience for him.

Both Allen and Stott were intent on understanding climate change’s role in extreme weather events. Stott utilized existing climate models to simulate two scenarios of the 2003 heatwave: one reflecting the climate of that year and another devoid of human-induced warming.

They ran extensive model simulations and concluded that in their landmark 2004 paper in Nature, human activities have more than doubled the likelihood of experiencing a heatwave similar to that of 2003.

This groundbreaking work marked the inception of a new climate science field, which began to identify human influences on extreme weather events. Soon analyses emerged for diverse phenomena, from heatwaves to severe droughts and storms.

However, a significant challenge remained—post-event analyses often took months or years to determine the influence of climate change.

To address this, researchers, including Friederike Otto from Imperial College London, founded World Weather Attribution in 2014. This initiative facilitates swift analysis of extreme weather events, quantifying the probable impacts of climate change, with results frequently released within days.

This has dramatically altered reporting on such events globally, enabling news outlets to directly attribute deadly weather phenomena to climate change and emphasizing the real-world consequences of rising emissions.

As Otto stated, “When we began this work a decade ago, scientists and journalists maintained that individual weather events could not be blamed on climate change. That perspective has shifted immensely.”

This advancement also supports climate change litigation, with causal investigations providing evidence in numerous lawsuits against polluters worldwide. In 2022, the United Nations announced a new International Loss and Damage Fund, paving the way for climate change compensation.

In 2003, Allen queried: “Could litigation for climate change be feasible?” Thanks to developments in attribution science, the answer is now a definitive “yes.”