Natural - not 'man made'. What does this entail? Try a super concentrated extremely effective gas that traps heat.

I am not a believer in global warming due to 'man made' issues expecially after the Michael Mann 'hockey stick' corrupt data he fed to the U.N. to alarm people back in the late 90's.

Methane is the one gas we do not want flowing freely as it is from the atmosphere - unless you want things to get hotter and hotter.

No idea what the solution is. Out of my pay scale.