A nature-based negative emissions technology able to remove atmospheric methane and other greenhouse gases

Abstract

Abstract Fulfilling the Paris Climate Agreement requires reducing rapidly the new emissions of greenhouse gases (GHGs) to reach net zero by 2050. As some anthropogenic emissions cannot be zero, to compensate them it will be necessary to remove GHGs from the atmosphere. Among possible methods, the Iron Salt Aerosol (ISA) offers new possibilities, including removal of methane and several other GHGs, as well as carbon dioxide. Several studies suggest that anthropogenic emissions of iron participate in the current primary productivity. As plans to decarbonize the world economy might also have inadvertent warming effects due to the reduction of iron emissions from fossil fuels burning, iron additions might help address this issue. ISA is different from the method known as Ocean Iron Fertilization and the differences are explained. ISA mimic natural processes and the dust which probably participated in the cooling during the ice-ages over the past million years. Still larger laboratory trials, safety and environmental impact studies and global chemical computer modeling are necessary before ISA would be ready to be trialed. Desk and laboratory studies indicate low cost, easy deployment and efficacy, all of which can be validated by future small scale field trials, a step needed before, if successful, a possible implementation at a climate-relevant scale.