By Luigi Jorio, Nov 17th 2022
Climate engineering or geo-engineering, involving deliberate large-scale manipulation of the Earth’s climatic system, has long been thought politically taboo. Today it meets with growing interest. Tom Wang / Alamy
Technologies that deflect the sun’s rays could prevent heatwaves and droughts. Yet they could also have undesiderable effects on ecosystems and human populations. Switzerland wants to see a study on the potential and risks of these technologies. But some scientists are calling for an immediate ban on an idea they believe to be “harmful to humanity”.
A plane with a wingspan of about 100 metres takes off from an airport in the US. There are no passengers or goods on board. There isn’t even a pilot. This aircraft is remote-controlled from the ground and is equipped with storage tanks and a vaporiser. Once it reaches the stratosphere, at an altitude of about 20km, it disperses billions of particles of sulphur dioxide. The aim is to reflect back a portion of the sun’s rays into outer space.
The year is 2042 and the planet has heated up 1.5° C over what it was in preindustrial times. Most coral reefs have disappeared and agricultural production in tropical regions is in drastic decline. Every year, tens of millions of people have to flee coastal cities due to the rise of sea levels and the most arid zones due to worsening drought.
Spraying molecules of sulphur dioxide into the stratosphere would bring a temporary reduction in temperatures at the earth’s surface, as happens after a major volcanic eruption. In 1991, dust cast off into the atmosphere by the eruption of Mount Pinatubo in the Philippines cooled the earth by 0.5 °C for a period of two years.