‘Sun blocking’ technologies – also known as ‘solar radiation modification’ – could theoretically cool down the earth by reflecting sunlight back into space.
One idea involves pumping sun-blocking particles into the upper atmosphere. This process of ‘stratospheric aerosol injection’ would involve planes spraying an aerosol like sulfur dioxide into the stratosphere.
This mist of particles would reflect the sun back upwards, shading the earth. The method has already worked – albeit accidentally. When Mount Pinatubo in the Philippines erupted in 1991, it released thousands of tons of sulphur dioxide. The global temperature temporarily dropped by 0.5°C.
In September 2022, researchers at Yale university argued that the injection method could hypothetically refreeze the poles.
Today, several news outlets are reporting that the UN wants to ‘explore’ this technique.
This could give the impression that the organisation has approved sun blocking as a viable tool to fight climate change.
Unfortunately for tech enthusiasts, this is not the case.
The UN Environmental Program’s recent report into Solar Radiation Modification concludes that it is not currently a realistic or wise plan.
“UNEP concurs with the panel that, at present, large-scale, or operational deployment of SRM technologies is not necessary, viable, prudent or sufficiently safe, given the limited scientific understanding and uncertainty about the potential impacts and unintended consequences,” says UNEP’s Chief Scientist Andrea Hinwood.
“The review concludes that SRM cannot replace reducing greenhouse gas emissions.”
Nonetheless, the body doesn’t rule out the method altogether, with the report concluding that their assessment of the technique “may change should climate action remain insufficient”.
