Modelling the effects of planetary climate control

Geo-engineering offers futuristic solutions to global warming, but these technologies are untested. An EU-funded project set out to model the effects, both positive and negative, of such climate-control strategies.

The Intergovernmental Panel on Climate Change (IPCC) has stated that the present spate of global warming is very likely to be linked to human activities since the pre-industrial period. One way to combat climate change is through geo-engineering, otherwise known as climate remediation or climate intervention. This is the deliberate manipulation of the global climate using technical measures.

There are two types of geo-engineering: strategies to remove carbon dioxide from the atmosphere and techniques for managing solar radiation. Solar radiation management (SRM) seeks to control global warming by reducing the amount of sunlight absorbed by the Earth. Simple examples include 'cool roof', which would involve using pale-coloured roofing and paving materials worldwide to reflect sunlight.

Other solutions proposed, although technically feasible, sound more like science fiction. These include whitening clouds to make them more reflective, pumping reflective aerosols into the stratosphere and deploying giant space sunshades. Needless to say, these ideas have not yet been tested. Although many scientists accept them as a complementary solution to climate change, others are concerned by their potential side effects.

For its part, the IPCC concluded in 2007 that geo-engineering options remained largely unproven. In this context, the study of geo-engineering options was proposed to prepare for the eventuality that mitigation efforts might not succeed in halting run-away climate change.

Financed by the Seventh Framework Programme's (FP7) Environment sub-programme, the 'Implications and risks of engineering solar radiation to limit climate change' (Implicc) project modelled various SRM solutions to test their effectiveness and implications for the eco-system and society.

The project team studied the effectiveness, side-effects, risks and economic implications of climate engineering. Efforts focused on space-borne reflectors, sulphur injections into the stratosphere and engineering low-level marine clouds through sea salt injections. Implicc deployed state-of-the-art climate models to quantify the effectiveness and side-effects of these geo-engineering concepts.

More details can be found at the following link: http://cordis.europa.eu/fetch?CALLER=OFFR_TM_EN&ACTION=D&RCN=10964