Curb emissions or face geoengineering uncertainty, report warns

The future of the Earth could rest on unproven and possibly dangerous geoengineering techniques if we fail to prevent climate change by cutting CO2 emissions drastically, a new report from the Royal Society in the UK warns. The report, 'Geoengineering the climate: science, go...

The future of the Earth could rest on unproven and possibly dangerous geoengineering techniques if we fail to prevent climate change by cutting CO2 emissions drastically, a new report from the Royal Society in the UK warns.

The report, 'Geoengineering the climate: science, governance and uncertainty', makes it clear that unless future efforts to reduce greenhouse gas emissions are taken more seriously and acted on swiftly, it will be necessary for to use geoengineering techniques to help mitigate the effects of climate change.

Several geoengineering technologies have been studied and some have been found to be viable for use in climate change mitigation and emissions reduction; however, the report pinpoints uncertainties and possible dangers in their adoption.

Professor John Shepherd of the University of Southampton, chair of the study, said, 'It is an unpalatable truth that unless we can succeed in greatly reducing CO2 emissions, we are headed for a very uncomfortable and challenging climate future, and geoengineering will be the only option left to limit further temperature increases.

'Our research found that some geoengineering techniques could have serious unintended and detrimental effects on many people and ecosystems - yet we are still failing to take the only action that will prevent us from having to rely on them. Geoengineering and its consequences are the price we may have to pay for failure to act on climate change.'

The study made an assessment of the two main kinds of geoengineering techniques: carbon dioxide removal (CDR) and solar radiation management (SRM). CDR techniques address the root cause of climate change by removing greenhouse gases from the atmosphere, while SRM techniques attempt to offset effects of increased greenhouse gas concentrations by causing the Earth to absorb less solar radiation, the report explains. CDR techniques are considered to be safer than SRM as they are they work in a more straightforward way to remove emissions from the atmosphere.

In particular, SRM techniques such as the use of stratospheric aerosols are much more of an unknown quantity as compared to CDR. They do not affect CO2 production; therefore, they do not mitigate other climate change effects associated with CO2 emissions like ocean acidification, for instance. 'Methods that act rapidly by reflecting sunlight may prove to be ineffective in offsetting changes in rainfall patterns and storms, but current climate models are not sufficiently accurate to provide a reliable assessment of these at the regional level,' according to the report.

SRM techniques would also have to be used over a very long time period. While they may help to cool the Earth's temperature, they may also create problems. The Royal Society's study concludes that SRM techniques are not a feasible alternative to reducing CO2 emissions and it would be feasible to use them only in a situation where actions to cool the planet must be taken rapidly.

In addition, neither technique has yet been shown to work at affordable costs and with acceptable impacts on the environment. Professor Shepherd explained, 'None of the geoengineering technologies so far suggested is a 'magic bullet', and all have risks and uncertainties associated with them. It is essential that we strive to cut emissions now, but we must also face the very real possibility that we will fail.'

'Geoengineering of the Earth's climate is very likely to be technically possible,' the report reads. 'However, the technology to do so is barely formed, and there are major uncertainties regarding its effectiveness, costs, and environmental impacts.'

'If 'Plan B' is to be an option in the future, considerable research and development of the different methods, their environmental impacts and governance issues must be undertaken now,' Professor Shepherd stressed. 'Used irresponsibly or without regard for possible side effects, geoengineering could have catastrophic consequences similar to those of climate change itself. We must ensure that a governance framework is in place to prevent this.'

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