A senior American climate scientist has spoken of the fear he experienced when US intelligence services apparently asked him about the possibility of weaponising the weather as a major report on geo-engineering is to be published this week. During a debate on the use of geo-engineering to combat climate change ... Prof Robock said: I got a phone call from two men who said we work as consultants for the CIA and we'd like to know if some other country was controlling our climate, would we know about it? "I told them, after thinking a little bit, that we probably would because if you put enough material in the atmosphere to reflect sunlight we would be able to detect it and see the equipment that was putting it up there. "At the same time I thought they were probably also interested in if we could control somebody else's climate, could they detect it?" Professor Robock, who has investigated the potential risks and benefits of using stratospheric particles to simulate the climate-changing effects of volcanic eruptions, said he felt "scared" when the approach was made. "I'd learned of lots of other things the CIA had done that haven't followed the rules and I thought that wasn't how I wanted my tax money spent. Professor Robock's concerns come as a major report on geo-engineering is to be published this week by the US National Academy of Sciences. Among the report's list of sponsors is the "US intelligence community." The professor alleges that ... the US government had a proven history of using the weather in a hostile way.