Solar Radiation Management: Playing with the Sun

Solar Radiation Management: Playing with the Sun

The most dramatic ideas involve altering how much sunlight reaches Earth. Scientists have proposed releasing sulfur dioxide into the stratosphere, mimicking the cooling effect of volcanic eruptions. Others suggest deploying giant mirrors in space or using ships to spray seawater into the sky to make clouds more reflective.

The appeal is speed. SRM could, in theory, cool the planet within years—far faster than cutting emissions alone. But the dangers are enormous: tampering with sunlight could disrupt rainfall, damage crops, and create geopolitical conflicts over who controls the thermostat.

Carbon Dioxide Removal: Cleaning the Air

Compared to SRM, carbon removal is less risky but slower. Nature already provides tools—forests, wetlands, and oceans absorb CO₂. Scaling up these natural sinks could make a difference, but land and resources are limited.

That’s why scientists are turning to technology. Companies like Clime works are building direct air capture facilities that filter CO₂ from the atmosphere and store it underground. Others explore enhanced weathering, spreading crushed minerals that naturally absorb CO₂.

The challenge is scale: billions of tons of carbon must be removed annually to make a meaningful dent. Current technologies are expensive and energy-intensive.