Climate change is likely to trigger abrupt and potentially persistent changes in the structure and function of marine ecosystems. Such ‘regime shifts’ threaten the livelihoods of millions of people reliant on small-scale fisheries. Yet, it is largely unknown how resource users cope with regime shifts, their uncertainty, and impacts. Here, we assess the potential for local collective action to avert uncertain, yet catastrophic, regime shifts. We conducted behavioural economic experiments with small-scale fishers (n=256) using a framed, dynamic common pool resource game to test the effect of different degrees of uncertainty about the presence of climate-induced thresholds on exploitation patterns. Results from four communities in the Colombian Caribbean show that groups facing uncertain thresholds are likely to adapt in the sense that they sustain higher stock levels in order to avoid a regime shift. However, catch inequalities in the game, and community-level attributes appear to mitigate or even eliminate this effect; illustrating the critical role contexts play for behaviour. Our results suggest a more positive outlook regarding the inherent uncertainties of climate change compared to experimental evidence overwhelmingly proposing a negative relationship between uncertainty, collective action, and sustainable resource use. Instead, we conclude that in certain circumstances uncertainty can help protect the commons.