Last Exit Climate Engineering? On the discussion about radiation management when climate targets are about to be exceeded - As overshoot of global climate targets looms, some researchers have suggested to assess the potential of radiation management methods to avoid dangerous climate change. This discussion is highly controversial, driven not only by great geophysical uncertainties but also the challenges of global climate politics: can radiation management serve as a potential measure against dangerous effects of climate change? How could this be determined – and by whom? This chapter highlights basic concepts in the context of current climate policy and introduces the contested debates around a so-called »risk-risk« framework.