Hopes of averting a climate catastrophe by investing in space-age technologies such as mirrors in orbit were dashed yesterday by a Royal Society report that found serious drawbacks with nearly all the methods proposed.

In the first comprehensive report by an influential science academy into the costs and benefits of "geo-engineering" technologies - those intended to compensate for the warming effects of greenhouse gas emissions on the climate by reflecting sunlight or removing carbon from the air - the Royal Society said the ideas were "dangerous and unproven".