by Erica Rex

Question: since we’re the ones responsible for breaking the climate, shouldn’t we be the ones to fix it?

This is exactly the question posed by climate scientists at the The Royal Society, a hallowed UK institution whose past members include such luminaries as Sir Isaac Newton and Charles Darwin. Last week, the society issued a study called “Geoengineering the Climate: science, governance and uncertainty.” The study points out that it is likely the Earth will warm two degrees this century, unless global greenhouse gas emissions are reduced to 50% of 1990 levels by 2050. A carbon-reducing diet of this magnitude would put us around the 175 parts per million (ppm) range. Today’s levels are around 388 ppm. The absolute peak – the concentration at which global warming will become irreversible, even if we stop emitting greenhouse gases altogether – is 450 ppm.

Geoengineering, the manipulation of planetary climate to counteract anthropogenic climate change, could reduce greenhouse gas emissions and curtail global warming.
Geoengineering methods can be divided into two main categories:

• removing carbon from the atmosphere

• managing the amount of sunlight that reaches the Earth’s surface.

The first option is safer, slower and far more costly. In this model, organic systems, such as forests and blue-green algae, would be harnessed into doing what they already do: pulling carbon from the atmosphere and producing oxygen.

The second option, solar radiation management, involves reducing the amount of solar radiation entering the Earth’s atmosphere through the use of various kinds of reflective surfaces. Proposals include pumping sulfate and other aerosols into the atmosphere. Other ideas include deploying crewless ships to spray salt water into the sky, thereby creating a dense cloud cover which would reflect more sunlight. And then there are suggestions like using mirrors in deserts to increase Earth’s surface albedo (reflectivity), or painting every roof on the planet white.

There are drastic consequences to both methods. But we’ve created a dire situation. The climate that has fostered us for 10,000 years and enabled us to become the master species is on the verge of collapse.

Don’t desperate times call for desperate measures?

One scientist comments that 450 ppm is not “some magic number.” It was the number chosen years ago to provide a basis for stabilization experiments. Temperatures associated 450 ppm are not certain: they could be less than 2 degrees, but might be as high as 4.