Scientists Are Coming Up With ‘Last Ditch’ Remedies for Climate Change: Richard Branson, the billionaire chairman of Virgin Group Ltd., has offered a $25 million prize for the best solution

As talks aimed at slowing global warming drag on, researchers are pushing new ideas that some are calling last-ditch attempts to avert the worst effects of climate change.

Some proposals are uncontroversial, such as using charcoal to lock carbon dioxide into soil or scattering carbon-absorbing gemstones.

Richard Branson, the billionaire chairman of Virgin Group Ltd., has offered a $25 million prize for the best solution in the field known as geoengineering.

 Louise Downing