Negative emissions techniques (NETs) promise to capture greenhouse gases from the atmosphere and sequester them. Since decarbonisation efforts have been slow, and the climate crisis is intensifying, it is increasingly likely that removing greenhouse gases from the atmosphere will be necessary to meet internationally-agreed targets. Yet there are fears that pursuing NETs might undermine other mitigation efforts, primarily the reduction (rather than removal) of greenhouse gas emissions. This paper discusses the risk of this phenomenon, named ‘mitigation deterrence’. Some of us have previously argued that a cultural political economy framework is needed for analysing NETs. Such a framework explains how promises of future NETs deployment, understood as defensive spatio-temporal fixes, are depoliticised and help defend an existing neoliberal political regime, and its inadequate climate policy. Thus they risk deterring necessary emissions reductions. Here we build on that framework, arguing that to understand such risks, we need to understand them as the result of historically situated, evolving, lived practices. We identify key contributing practices, focussing in particular but not exclusively on climate modelling, and discuss how they have been reproduced and co-evolved, here likened to having dug a hole for ourselves as a society. We argue that understanding and reducing deterrence risks requires phronetic knowledge practices, involving not just disembodied, dispassionate technoeconomic knowledge-making, but also strategic attention to political and normative issues, as well as emotional labour. Reflecting on life in the hole hurts.