Why Europe's worst-ever heatwave would have been impossible without climate change

📌 Summary:

• A World Weather Attribution (WWA) study found climate change "unequivocally to blame" for Europe's ongoing heatwave — described as the most severe ever recorded in Europe
• This is the third intense heatwave in five years (after 2022 and 2023, in which an estimated 1,00,000+ people died from extreme heat)
• WWA was categorical that the cause is climate change, NOT El Nino — it found the El Nino Southern Oscillation (ENSO) phase had no role in driving this spell
• Key data: both daytime highs and overnight temperatures would have been "virtually impossible" at this time of year as recently as 1976 (50 years ago); record-breaking night temperatures are ~100 times more likely today than in 2003, and daytime peaks ~10 times more likely
• Many records being broken were set in 1976; June temperatures, usually 20-30 C (day) and 11-17 C (night), have run 10-15 C above normal in many areas
• Warning: July is historically Europe's hottest month, and with El Nino expected to strengthen in July, fresh heatwave spells may follow
• Significance of attribution science (a discipline ~two decades old): it quantifies how much more likely/intense an event is due to climate change, and WWA's faster methods now allow assessments even while an event is ongoing

🎯 UPSC Relevance: GS3 Environment — climate change impacts (extreme weather/heatwaves), attribution science, and the El Nino/ENSO link; relevant to disaster preparedness.

📝 Prelims Facts:

• World Weather Attribution (WWA) is a global scientist group that studies the role of climate change in extreme weather
• ENSO (El Nino Southern Oscillation) is an ocean-atmosphere interaction over the Pacific; El Nino warms, La Nina cools global temperatures
• Europe's first heatwave of this century was in 2003; 1976 was a benchmark hot summer

🔑 Key Term: Attribution science — the field that estimates how much human-induced climate change has altered the likelihood or intensity of a specific extreme weather event.