A ‘geoengineering cocktail’ is the latest last-ditch proposal to reverse climate change – CNET

Editors’ note: Dear Future is a collaboration between CNET and VICE Motherboard that looks at major innovations — in robotics, space travel, VR and more — shaping the world around us. 

Earth is warming, and much of the uptick on our planetary thermostat is caused by human activity. Though many leaders persist in denying this reality, intense natural disasters and accelerated extinction rates are canaries in the coal mine for anthropogenic climate change, among many other worrisome trends.

Ideally, the response to this clear threat to civilization would be to reduce greenhouse gas emissions from the consumption of fossil fuels, which is the major culprit behind human-driven climate change. That’s why world leaders convened in Paris to hash out a gameplan for capping the rise in global mean temperature rise to 2°C above the preindustrial average. But President Donald Trump’s recent decision to pull the United States out of the Paris Agreement, signed in 2016, underscores a growing demand for a “plan B” to confront climate change, in case nations fail to get their act together in time to prevent catastrophic temperature increases.

One controversial solution is climate geoengineering, the notion that we could halt or reverse the warming of Earth with technological intervention. These concepts have historically fallen into two camps: solar radiation management and greenhouse gas removal.

The solar approach aims to boost Earth’s albedo, or reflectivity, by introducing reflective aerosols to the stratosphere (as one example). These compounds would bounce sunlight back into space, thereby cooling the planet, almost like an Earth-scale version of painting your roof white. Greenhouse gas removal, meanwhile, would focus on scrubbing warming gases, especially carbon dioxide, from the atmosphere using a range of techniques.