Like it or fear it, there is a serious wealth of money already flowing into research on geoengineering solutions to climate change. These range from fairly familiar technologies, such as carbon capture and sequestration, to more speculative, highly ambitious ideas such as ‘solar radiation management’ (SRM).

There are huge unknowns in each and every area of enquiry here, but potentially some huge benefits, too. Faced with the growing threat of runaway global warming and the lack of a commensurate response by way of emissions reductions, it’s hardly surprising that some see geoengineering as our last, best hope of stabilising the climate. Seen in this light, exploring a range of what may appear to be outlandish technologies, such as mass sulphur injections into the atmosphere, or spraying saltwater into the sky to increase the reflectivity of clouds, represents a legitimate investment in long-term insurance. However, many are already deeply concerned at the possibility of unintended consequences resulting from such global-scale meddling. They ask whether the tantalising prospect of 'fixing' the climate could distract us from a controversial but absolutely essential challenge of cutting emissions.

In this Special Edition, we explore the potential – and pitfalls – of this approach, and ask the question: 'Can we reengineer the climate?'.