Guest essay by Eric Worrall
With the prospect of trillions of dollars of climate cash well and truly fading, researchers seem to be bidding down the price tag for saving the planet.
Blocking out the sun to fight global warming: Bob McDonald
Solar geoengineering is controversial but proponents say we have no choice
By Bob McDonald, CBC News Posted: Mar 31, 2017 5:55 PM ET Last Updated: Mar 31, 2017 5:55 PM ET
In light of the new U.S. administration’s decision to cut back on environmental protection and cultivate the coal industry, carbon emissions are unlikely to go down over the next four years.
So scientists are considering a scheme to shade the atmosphere from the sun and cool the Earth to compensate for global warming. It’s a risky plan.
The concept is called Solar Geoengineering. One of the ways it could work, scientists say, is by injecting tiny particles high into the atmosphere, where they where together they would act as a sun shield, reflecting sunlight back into space and cooling the planet.
When Mt. Pinatubo erupted in 1991, 20 million metric tonnes of sulphur dioxide was blown into the stratosphere. There the molecules reacted with water vapour to form tiny particles that were carried on high altitude winds, producing a global haze. The average temperature of the Earth dropped by 0.5 C for more than a year after the eruption.
The geoengineering project would do the same thing on a much smaller scale, using a fleet of aircraft to spray 250,000 metric tonnes of sulphur dioxide, or some other material such as calcite into the lower stratosphere.
Scientists estimate that by brightening the atmosphere with these particles, they could reflect one percent of sunlight back into space and provide enough cooling to balance the warming effect of the carbon emissions coming from industry.
Harvard Professor David Keith estimates the project would have to be an international effort and cost about $1 billion to $10 billion per year. That sounds like a lot, but it pales compared to the U.S. military budget, for example, which is expected to increase to $639 billion dollars in 2017.
While it might seem tempting to take this special offer price for saving the world, I suggest if we wait a bit longer, we might see even more extraordinary price cuts. Who knows, next year’s price for saving the world might be a 100K research grant and a few packs of smokes.