Tinkering with climate could reduce rainfall

Tinkering with the Earth’s climate systems to minimise climate change — a process known as “geoengineering” — could have unintended consequences, including possible major disruptions to the planet’s water cycles, according to recently published research.

Writing in the journal Science, climate scientists Susan Solomon of the National Oceanic and Atmospheric Administration and Gabriele Hegerl of the University of Edinburgh warn that much of the debate over geoengineering not only downplays the possible negative impacts but “creates a false sense of security.”

Solomon and Hegerl aren’t the one researchers to have expressed concern about geoengineering strategies such as shooting sulphur into the atmosphere or using mirrors to deflect sunlight away from the Earth. Last year, scientists at the Lawrence Livermore National Laboratory published a study finding a correlation between reduced sunlight and lower levels of rainfall.

For example, after the Philippines’ Mount Pinatubo erupted in 1991 and shot massive amounts of sulphur into the upper atmosphere, scientists observed not only reduced temperatures but lower levels of both rainfall and streamflow.