Heat curbing plan hatched

– Spraying sun-dimming chemicals high above the Earth to slow global warming could be “remarkably inexpensive”, costing about $2.25 billion a year over a 15-year period, according to a study by US scientists.

Some researchers say the geo-engineering technique known as stratospheric aerosol injection (SAI) could limit rising temperatures that are causing climate change. It would involve the use of huge hoses, cannons or specially designed aircraft to spray large quantities of sulphate particles into the upper layer of the atmosphere to act as a reflective barrier against sunlight.

Total costs to launch an SAI effort 15 years from now would be $3.5 billion (R48 billion), scientists at Harvard University said in a report published in the journal Environmental Research Letters, adding that average annual operating costs would be $2.25 billion a year over 15 years. An aircraft would have to be designed to fly at an altitude of about 20km and carry 25 tons. After input from aerospace companies, the scientists have developed a design that could work. – Reuters

London