Image: NASA

The deadline is clear: we must cut our carbon emissions in half by 2030 in order to avoid catastrophic and irreversible effects of climate change. 

After a brief COVID-19-induced dip, carbon emissions are shooting upwards again with no sign of slowing down. Transitioning away from fossil fuel use is a monumental undertaking that will require enormous societal and economic restructuring. As the climate clock ticks, nations stumble through climate decision making, and achieving the necessary reductions in time seems impossible. 

But what if we could buy ourselves more time? 

Cutting carbon emissions is essential to curbing the effects of climate change, but it is not our only hope. Advocates for geoengineering argue that manipulating the environmental processes that underlie global warming is critical to stabilize the climate. 

The two main schools of geoengineering thought are simple: remove existing carbon from the atmosphere or solar geoengineering to prevent more sun from getting in. 

The “negative emissions” approach of sucking carbon from the atmosphere would help to de-insulate the planet, allowing more low-energy heat to travel through the atmosphere and back out to space. A firm called Carbon Engineering has already designed a machine that uses a series of simple chemical reactions to isolate and capture pure carbon dioxide gas from the atmosphere before burying it underground.

Solar geoengineering projects propose spraying a fine mist, either of seawater or sulfate aerosols, into the atmosphere to reflect some sunlight back into space. Usually, high-energy sunlight enters the atmosphere and is absorbed into the planet, then re-emitted from the earth as lower-energy heat, which gets trapped in our increasingly greenhouse gas-rich atmosphere. Solar geoengineering would deflect some high-energy sunlight, never giving it a chance to be trapped as heat.

These types of projects could slow warming and extend the deadline set by the Intergovernmental Panel on Climate Change (IPCC), giving us time to make the necessary changes to prevent complete climate disaster.

Despite its promise, geoengineering strategies  attract sharp criticism for interfering with natural processes or attempting to “play god.” Some critics point to the lack of research on the potential detrimental effects of geoengineering projects, like pollution from introduced aerosols or crop failure from a dimmed sun. Others worry that providing alternatives to cutting carbon emissions will decrease the sense of urgency that has driven decades of climate activism and policy advancements. 

I hope to examine all sides of the controversy and explore the potential of geoengineering as a tool in the fight against climate change. What are the risks and rewards of geoengineering projects? Who stands to benefit the most from geoengineering, and who will bear the costs? How are we, as humans, responsible for the planet we call home? Can we save it?