Geoengineering

Geoengineering is risky and unproven, but soon it might be necessary

Changing the complex system that is our planet sounds difficult. That much is clear. However, the good news — if melting ice-caps and increasing numbers of freak weather events can ever be considered “good” — is that we know it can be done. We’ve done it before. The industrialization which led to our current level of climate change was a form of geoengineering, albeit an unintentional one.

Fortunately, today’s geoengineering proposals aren’t quite as apocalyptic as Harry Wexler’s meteorological bombing campaign. Broadly speaking, they fall into one of two camps. The first is what is known as Solar Radiation Management (SRM) or solar geoengineering: Reflect some of the Sun’s energy back into space, thereby offsetting the temperature rise caused by the increased levels of greenhouse gases in the atmosphere.

Two of the leading suggestions for carrying out solar geoengineering involve space reflectors for blocking some sunlight before it reaches Earth, or using stratospheric aerosols containing small, reflective particles to bounce sunlight from the upper atmosphere.

In the other corner is what is termed Greenhouse Gas Removal (GGR) or carbon geoengineering. This seeks to remove carbon-dioxide and other greenhouse gases from the atmosphere by sucking it out of the air. This could be achieved (among other potential methods) through massive tree-planting efforts, adding nutrients to the ocean to draw carbon-dioxide from the atmosphere, or building large machines which remove carbon-dioxide from ambient air and store it.