Injecting sulphates into the atmosphere while also reducing carbon emissions could help stabilize climate change, a new computer model suggests.

The model, prepared by the National Center for Atmospheric Research in Boulder, Colo., suggests that an approach using both methods would be more effective than either one alone.

The idea of releasing large amount of sulphate particles into the atmosphere to block a portion of the sun's rays has been around since the 1970s.

Proponents of the scheme say it could cool the climate for a year or more after each application, in the same way that volcanic eruptions can result in cooler temperatures the following year.

NCAR's Tom Wigley ran several scenarios in the computer model. One simulated cutting carbon emissions immediately and lowering them by 50 per cent in the next 50 years.

Another allowed for increasing emissions until the 2030s before the cutbacks begin. In those cases, Wigley found that simulating volcanic-scale sulphate emissions every year, every two years or every four years can keep global temperatures about constant, even with increasing carbon emissions, for the next 40 to 50 years.

The research, appearing in Thursday'sissue of the journal Science,doesn't endorse any method for mitigating global climate change, but does examine whether injecting sulphates into the atmosphere could cool the Earth's climate.

The study is a purely theoretical work and doesn't explore the technical, political or environmental feasibility of intentionally altering the Earth's climate, a theoretical field called geoengineering.

The computer model simulated injecting sulphate particles in amounts similar to those released by the eruption of Mt. Pinatubo in the Philippines in 1991.

Injecting sulphates, even if it is feasible, won't cure all of the Earth's environmental problems, Wigley wrote. The increased carbon dioxide in the atmosphere has also acidified the oceans.