The modern concept of geoengineering's usually taken to mean proposals to deliberately manipulate the Earth's climate to counteract the effects of global warming from greenhouse gas emissions. The National Academy of Sciences defined geoengineering as "options that'd involve large-scale engineering of our environment in order to combat or counteract the effects of changes in atmospheric chemistry." Some geoengineering techniques are based on carbon sequestration. These seek to reduce greenhous… (More on Geoengineering)