A popular plan to fix climate change could have an unexpectedly disastrous effect

Sep 23 2026 · 2 min read

illuminem summarises for you the essential news of the day, reviewed by our editorial team. Read the full piece on BGR or enjoy below:

🗞️ Driving the news: Marine cloud brightening, spraying sea-salt particles into low clouds to reflect more sunlight, could cool the planet but may disrupt the El Niño Southern Oscillation (ENSO)
• A 2025 UCSB study found in simulations that the technique could reduce ENSO amplitude by 61%, potentially altering rainfall patterns across the Pacific

🔭 The context: The proposal aims to mimic some cooling effects of volcanic eruptions such as Mount Pinatubo in 1991
• However, cooling ocean surfaces could reduce evaporation, while smaller aerosol particles may make clouds less effective at producing rain
• The study therefore cautions against deploying marine cloud brightening over the Pacific.

🌍 Why it matters for the planet: Disrupting ENSO could affect rainfall and monsoon systems that support agriculture across Southeast Asia and other regions
• The findings highlight that solar geoengineering could reduce temperatures while creating significant regional climate trade-offs

⏭️ What’s next: Researchers also modelled stratospheric aerosol injection, which places particles higher in the atmosphere and produces more evenly distributed cooling
• In their simulations, this approach did not significantly alter ENSO, but both techniques remain areas of scientific research rather than established climate solutions

💬 One quote: “The study's authors advocate against using marine cloud brightening over the Pacific.”

📈 One stat: 61% — the simulated reduction in ENSO amplitude under marine cloud brightening conditions.

Subscribe to our free newsletters to never miss a beat in sustainability.

The world needs sustainability knowledge. At illuminem, no interest group or shareholder can influence our work. Thank you for supporting our mission to make high-quality and independent sustainability information free for all. Every contribution helps. Thank you for donating today