The built environment takes up an ever greater portion of the earth’s surface. This mostly unused surface area could be coated in albedo enhancing paints or material which would allow them to reflect incoming sunlight.
Inspired by the discovery of CO2 ice caps on Mars, Agee et al. (2013) suggested it might be possible to artificially create similarly cold conditions in the already frigid temperatures of Antarctica that would allow CO2 to 'snow' out of the air.
Enhanced weathering (EW) is a measure that seeks to enhance and speed up the process of rock weathering in which CO2 reacts with minerals (Schuiling and Krijgsman 2006) that naturally occurs and already consumes 1.1 Gt CO2 per year (Ciais et al. 2014).
One of the main issues with methane removal is that atmospheric methane concentrations are very low. This means that very large volumes of air, and related energy demands, are required, making the use of ventilators like those used for DACCS (see direct air capture) more complicated (Nisbet-Jones et al. 2021).
Apart from proposals to destroy atmospheric methane or capturing it, some have suggested it could be possible to prevent methane from reaching the atmosphere or flaring it.
