A bold idea to combat global warming has emerged, suggesting we could 'buy time' by reflecting sunlight back into space. But this innovative strategy, proposed by Britain's Royal Society, comes with a warning: the risk of 'rogue nations' causing more harm than good.
The Royal Society, a scientific powerhouse since the 17th century, believes reducing sunlight reaching Earth could slow global warming and limit climate change's impact. Their new report highlights two promising strategies: pumping reflective particles high into the atmosphere and making clouds over the sea whiter by spraying salt.
However, the report's authors caution that a nation acting alone could trigger extreme droughts and weather disruptions worldwide. Professor Keith Shine, who chaired the working group, acknowledges the risks but suggests a time may come when world leaders view solar radiation modification (SRM) as the least damaging option.
"It's not about whether SRM is safe; it's about managing risks," Shine explains. "At some point, the risks of SRM might seem less severe than the risks of unchecked climate change."
The report paints a grim picture of current global efforts to reduce greenhouse gas emissions, which seem unlikely to prevent global temperatures from rising above the 'safe' limit of 1.5C. The upcoming UN climate talks in Brazil offer a glimmer of hope, but under current policies, temperatures are projected to rise by at least 3C by 2100.
The working group ranks stratospheric aerosol injection as the most promising SRM technique. This involves planes flying at high altitudes to release sulphur dioxide gas, forming reflective particles that slightly reduce sunlight reaching Earth's surface.
Real-world evidence supports this approach. The 1991 eruption of Mount Pinatubo in the Philippines released 15 million tonnes of sulphur dioxide into the stratosphere, temporarily reducing global temperatures by 0.5C. Computer models suggest releasing 8 to 16 million tonnes of the gas annually could lower global temperatures by 1C.
The cost, estimated at 'low 10s of billions of dollars a year', is significantly less than the global economic losses and damage caused by extreme weather events and wildfires. For instance, Hurricane Melissa, intensified by global warming, caused up to $52 billion in damage and economic losses across the western Caribbean.
While SRM could temporarily reduce temperatures, the Royal Society emphasizes that it does not address climate change's root cause and is not a substitute for reducing emissions. If deployed, SRM might need to be sustained for over a century as carbon dioxide levels peak and begin to decline.
This controversial strategy raises important questions: Are we willing to accept the risks of SRM to buy time for emission reduction efforts? Could SRM technologies be effectively governed to prevent rogue nation actions? Share your thoughts in the comments; let's discuss the potential and pitfalls of this innovative approach to combating global warming.
