Telegraph: John Holdren said that the idea of geo-engineering the climate is being discussed. Options include cloud-seeding and shooting pollution particles into the upper atmosphere to reflect the sun’s rays. “It’s got to be looked at,” he said, even if such experimental measures were only used as a last resort. “We don’t have the luxury of taking any approach off the table.” Hospitals and schools could be powered by underground heat, says Royal Academy of Engineering In a further …