Would dimming the Sun cool the Earth?

Solar geoengineering could stop climate change, but it isn't without consequences.

Climate change is the biggest challenge facing the Earth today. Climate change (the long-term change in world weather patterns, caused by human activities) is causing rising temperatures and extreme weather events. However, what if there was a way to cool Earth by reflecting or dimming the Sun?

In 2022, the US company Make Sunsets released two weather balloons above Baja California in Mexico. These balloons were filled with the gases helium and sulfur dioxide. Once the balloons reached a certain height, they burst open, spreading sulfur dioxide particles across the sky. This substance creates a bright haze in the sky that reflects sunlight. A similar weather balloon test flight was launched in the UK, according to a report by MIT Technology Review magazine.

This method is one of a few ways of bouncing sunlight back into space, in a process known as solar geoengineering. Other examples include putting reflectors, or mirrors, onto satellites.

In a world of rising temperatures, dimming the Sun is an immediate way to cool the planet. Luke Iseman, the founder of Make Sunsets, claims that without solar geoengineering “there are no other realistic options to stay below 2°C”. Scientists have warned that if global average temperatures rise by more than 2°C above pre-industrial levels (1850– 1900), then many effects of climate change will be irreversible.