Climate engineering by mimicking natural dust climate control: the iron salt aerosol method

Abstract

Abstract. Power stations, ships and air traffic are among the most potent greenhouse gas emitters and are primarily responsible for global warming. Iron salt aerosols (ISAs), composed partly of iron and chloride, exert a cooling effect on climate in several ways. This article aims firstly to examine all direct and indirect natural climate cooling mechanisms driven by ISA tropospheric aerosol particles, showing their cooperation and interaction within the different environmental compartments. Secondly, it looks at a proposal to enhance the cooling effects of ISA in order to reach the optimistic target of the Paris climate agreement to limit the global temperature increase between 1.5 and 2 • C.Mineral dust played an important role during the glacial periods; by using mineral dust as a natural analogue tool and by mimicking the same method used in nature, the proposed ISA method might be able to reduce and stop climate warming. The first estimations made in this article show that by doubling the current natural iron emissions by ISA into the troposphere, i.e., by about 0.3 Tg Fe yr −1 , artificial ISA would enable the prevention or even reversal of global warming. The ISA method proposed integrates technical and economically feasible tools.

Biogenic Iron Dust: A Novel Approach to Ocean Iron Fertilization as a Means of Large Scale Removal of Carbon Dioxide From the Atmosphere

“…A better documented example of volcanic iron deposition occurred in the subarctic northeast Pacific Ocean, where a significant plankton bloom was observed following an eruption of an Aleutian Island volcano (Hamme et al, 2010). Finally, Oeste et al have proposed adding iron salts to the flue gases of hydrocarbon burning power plants as a way to distribute iron salts to the atmosphere (Oeste et al, 2017); these authors conclude such a scheme could lead to CO 2 draw down through processes not dissimilar to what is proposed here.…”

Effects of Sea Salt Aerosol Emissions for Marine Cloud Brightening on Atmospheric Chemistry: Implications for Radiative Forcing

“…The change in surface concentrations of most species is limited to the tropics, except surface ozone, which decreases on a regional to near-global scale due to its longer lifetime. These results have implications for another geoengineering method, which proposes using iron salt aerosol to release chlorine radicals that react with methane and ozone (Oeste et al, 2017).…”

The Effects of Carbon Dioxide Removal on the Carbon Cycle

“…Uncertainties may be highest for methods that have been investigated in only a few studies, or are merely conceptual proposals (Table 2 ). Such methods include artificial downwelling [ 106 , 107 ], coastal (blue carbon) sink management [ 66 , 98 – 100 , 109 ], cloud alkalinization [ 110 ], burial of terrestrial biomass on land or in the deep ocean [ 103 , 108 , 129 ], iron salt aerosol additions [ 130 ], storing carbon in structural materials [ 103 , 131 ], (e.g., by building with wood or carbon absorbing cements or utilizing it in other products), or extracting CO 2 directly from seawater [ 132 ]. There is also little knowledge about the effects that may emerge when any of these methods is scaled up to have globally significant impact.…”