Could Paint Particles Help Cool The Planet?
The June 12, 1991 eruption column from Mount Pinatubo taken from the east side of Clark Air Base.
Dispersing a microscopic, light-scattering particle found in paint and sunscreens into the upper reaches of the atmosphere could help cool our rapidly warming planet, scientists say.
Advocates of the idea say that scattering titanium dioxide – which is found in paint, sunscreens, and inks – into Earth's stratosphere could help deflect the sun's rays. The effect would be no different, they argue, from the global cooling effect created by the 1991 eruption of Mount Pinatubo in the Philippines, which spewed 20 million tons of sulphur dioxide into the stratosphere, forming a fine mist of sulphuric acid particles that reduced global temperatures for two years.
Peter Davidson, a member of the UK Royal Academy of Engineering, called the geoengineering project an insurance policy against climate change.
“While it's essential that we work to reduce carbon dioxide emissions now, it would be wise to have a well-researched emergency system in reserve as a Plan B,” Davidson said.
Scientists chose titanium dioxide because it is stable in air, non-toxic and seven times more effective at scattering light than sulphuric acid.
But how to get the titanium dioxide particles into the atmosphere? One idea is to use an air balloon to lift a flexible pipe up into the lower level of the stratosphere and then use a hypersonic nozzle to spray a chemical slurry that contains titanium dioxide.
Davidson and his colleagues estimate that the cost of the project would be around $4.8 billion per year.
Details about the geoengineering project are detailed in this month's tce magazine, a publication of the Institution of Chemical Engineers (IChemE).