In advance of its Fifth Assessment Report on climate change, which will be finalised in 2014, the Intergovernmental Panel on Climate Change is now holding expert meetings on the subject of geo-engineering. Large-scale technological measures and proposals, known in the field as geo-engineering, aim to contain global warming. Proposals range from releasing sulphur aerosols into the atmosphere and installation of solar sails in space to fertilisation of the oceans. Geo-engineering also includes the permanent subterranean storage of carbon dioxide. The Federal Environment Agency has reviewed the discussed proposals and determined there are potentially serious risks and side effects as well as many unanswered questions. The impact on the environment of fertilising the oceans is currently as difficult to determine as are the effects on regional climate and the stratospheric ozone layer of releasing additional sulphur aerosols to the atmosphere. Accordingly, the many downstream effects of geo-engineering projects cannot be fully accounted for, let alone predicted. Moreover, they might even be irreversible, which is grounds for the Federal Environment Agency to call for restrictive criteria to apply in exploring these technologies. As part of a moratorium, the actual implementation of any geo-engineering measures should not take place at this time.
The advocates of geo-engineering see the advantages of such engineering solutions to climate problems for it requires the population to make either no or only very slight changes in their behaviour. Furthermore, it does not require any long drawn-out international negotiations about emissions reductions. Yet these are only seeming advantages, for the notion of geo-engineering- that is to slow down global warming with large-scale technical interventions- does not address the causes of man-made greenhouse effect: emissions of carbon dioxide and other greenhouse gases. Instead, the already heated up climate is adjusted afterwards. Most geo-engineering measures have only been conducted in laboratories up to now and tested on a small scale. In-depth scientific research on which to base a valid evaluation is lacking. The effectiveness of many measures has thus not been proven in any way.
Proposals to intervene in the climate system with large-scale technological measures have been advocated for some time by supporters as an alternative in climate protection. The Cancun agreements of December 2010 mark the first official declaration in a UN resolution of the 2-degree goal to contain global warming by the international community of states. Just how to achieve that goal is a matter of dispute among the various countries. In its latest background paper, the Federal Environment Agency addresses geo-engineering in its current climate policy and explores legal frameworks. It assesses measures- insofar as is scientifically possible- in terms of their feasibility, effectiveness and environmental compatibility. In conclusion, the Federal Environment Agency defines criteria that can applied in policy decision-makers’ assessment, and it issues some initial recommendations on how to address the issue.
