Promises

Solar radiation management methods modify the rate at which the Earth absorbs solar radiation to lower global temperatures directly, but do not reduce the volume of CO2 in the Earth’s atmosphere. The modification of the biosphere interaction with solar radiation could potentially be achieved at a global scale (e.g., stratospheric aerosol scattering) or locally (e.g., heat reflection to protect and restore snow or glaciers).

Albedo is the amount of radiation that is reflected back.

Ground-based albedo modification techniques aim to increase the reflectivity of land surfaces by positioning reflectivity artefacts. These artefacts reflect away solar radiation.

• Using reflective materials on building roofs (e.g. whitening them),
• Installing reflectors in subtropical countries,
• Adopting land management practices such as no-till farming,
• Covering deserts or glaciers with reflective sheeting,
• Increasing reflectivity of the ocean.

While small-scale implementation of GBAM would have little effect upon radiative forcing, regional scale implementation of these techniques could reduce global radiative forcing by between 1-3C. To be most effective, these land-based reflectors would need to be in zones that receive substantial sunlight.

Opportunities

It’s quite easy to deploy locally and can keep cities cool. Example: The goal of the Arctic Ice Project is to slow climate change by protecting arctic ice with eco-friendly materials that reflect away the sun’s radiation. The project has been launched by a non-profit organisation with the objective to preserve arctic ice by spreading eco-friendly sands, protecting the ice below. The most promising solution proposes to deploy a thin layer of very small hollow glass microspheres across strategically chosen small regions of the Arctic to improve the reflectivity of sea ice, mimicking natural processes to reflect solar energy out of our atmosphere and restore the Arctic.