Which natural phenomenon can temporarily offset warming by cooling the planet?

• A. Dust and ash from volcanic eruptions
• B. Deforestation
• C. Ocean acidification
• D. El Niño

Answer: (A)

Dust and ash from volcanic eruptions can temporarily offset warming by cooling the planet. When a large eruption injects sulfur dioxide high into the atmosphere, it forms sulfate aerosols that reflect sunlight back into space. This extra reflection reduces the solar energy reaching Earth’s surface for months to a few years, depending on how long the aerosols stay in the stratosphere. The cooling is short-lived because those particles eventually settle out and temperatures can resume rising as greenhouse gases continue to trap heat. By contrast, deforestation tends to worsen warming by reducing carbon uptake and altering surface properties, ocean acidification affects ocean chemistry rather than temperature, and El Niño typically enhances warming rather than offsetting it.