CARBON CAPTURE NOT WORKING

Many question remain unanswered as to whether carbon capture, storage and sequestration (CCS), will work to lower global warming.

Professor Gary Shaffer from the Danish Centre for Earth System Science examined a range of CCS methods to determine their effectiveness and long-term impacts.

"CCS has many potential advantages over other forms of climate geoengineering," he said. "However, potential short and long-term problems with leakage from underground storage should not be taken lightly."

The study reveals leakage of sequestered CO2 could cause large scale atmospheric warming, sea level rise and oxygen depletion, acidification and elevated CO2 concentrations in the ocean.

Geological storage of CO2 - either underground or below the ocean floor - may be more effective, but only if leakage can be kept down to 1 per cent or less per 1,000 years.

Dr Peter Cook, chief executive of the Cooperative Research Centre for Greenhouse Gas Technologies, says Professor Shaffer's figures for geological sequestration mirrors the conclusions reached by the Intergovernmental Panel on Climate Change (IPCC).

Dr Cook, who was involved with the IPCC study, says "as long as you have the right rocks to store the carbon in, then sequestration will do what nature does anyway in keeping CO2 out of the atmosphere."