The ideas may sound like far-fetched schemes from an alchemist's notebook but scientists are pursuing them as many countries prepare to bury captured greenhouse gases in coming years as part of the fight against global warming

Part of the answer could be to petrify or liquefy gases like carbon dioxide -- emitted for example from power plants and factories run on coal, oil or natural gas -- if technical hurdles can be overcome and costs are not too high

Other researchers say pumping the gas into sediments below the seabed at depths of around 3,000 meters (9,800 ft) would expose it to enough pressure to turn it into a viscous liquid, like honey or treacle

The U.N. Climate Panel said in a 2005 report that carbon storage could be one of the main ways to offset global warming, which could cause more powerful storms and heatwaves, and melt glaciers from the Himalayas to the Andes

Costs might be even higher for the more exotic solutions