A US researcher has proposed a carbon dioxide sequestration method that would lock up one billion tonnes of the gas in solid form each year for five years in Antarctica.
Ernest Agee, a scientist in the Department of Earth and Atmospheric Sciences at Purdue University in Indiana, says his method was inspired by a NASA photograph from 2005 that showed a CO2 ice cap on the south pole of Mars.
"The presence of this CO2 ice cap triggered the idea to consider the possibility of terrestrial air CO2 deposition at Earth's South Pole, considering that this is the coldest location on Earth and the energy required to sequester CO2 from the atmosphere (and to maintain insulated storage) might be within the scope of reality," he writes in a research paper in the Journal of Applied Meteorology and Climatology.
A box freezer, 100m by 100m by 100m and standing on four corner pillars chills the Antarctic air to -153C by passing it through coils of frozen nitrogen.
The CO2 in this air then freezes into snow, which falls through the open bottom of the fridge, to be carted away to nearby insulated landfill bays 380m long and wide and 10m deep, where the frozen waste is compacted. Five bays in a semi-circle near the giant fridge would be filled, one each year, one after the other.
Energy for the operation would be provided by windfarms "that will be positioned appropriately for both logistics and katabatic wind currents".
Professor Agee says the prototype system could "process ambient air at a depositional rate of 0.4m of snow per 24-hour operational day".