Deploying giant space mirrors and spraying particles from stadium-sized balloons may sound like an engineer’s wild fantasy, but climate models suggest that the potential of geoengineering to offset rising atmospheric carbon dioxide may be significantly overstated.
Through a variety of computer simulations used for reporting to the Intergovernmental Panel on Climate Change (IPCC), the team investigated a scenario where an increase in the world’s atmospheric carbon dioxide levels was balanced by a “dimming” of the sun.
... “The first thing we realized was that we had to ‘dim’ the sun 25 percent more than expected, in order for the Earth’s systems to show a response, which translates to needing more geoengineering than previously thought,” says Schmidt.
A reduction in global rainfall is not necessarily an equal one. “It becomes interesting when you look into the regional responses,” continues Schmidt. “If you have just a carbon dioxide increase, most models predict a global rainfall increase, but a strong decrease in the Mediterranean and subtropics.
But if you try to balance this with geoengineering, these zones shift to Northern Europe, Northern Asia and North America.”