Nature-based solutions (NbS); working with and enhancing nature to address societal challenges, increasingly feature in climate change adaptation strategies. Despite growing evidence that NbS can reduce vulnerability to climate change impacts in general, understanding of the mechanisms through which this is achieved, particularly in the Global South, is lacking. To address this, we analyse 85 nature-based interventions across the rural Global South, and factors mediating their effectiveness, based on a systematic map of peer-reviewed studies encompassing a wide diversity of ecosystems, climate impacts, and intervention types. We apply an analytical framework of people's socialecological vulnerability to climate change, in terms of six pathways of vulnerability reduction: social and ecological exposure, sensitivity, and adaptive capacity. Most cases (95%) report a reduction in vulnerability, primarily by lowering ecosystem sensitivity to climate impacts (73% of interventions), followed by reducing social sensitivity (52%), reducing ecological exposure (36%), increasing social adaptive capacity (31%), increasing ecological adaptive capacity (19%) and/or reducing social exposure (14%). Our analysis shows that social dimensions of NBS are important mediating factors for equity and effectiveness. This study highlights how understanding the distinct social and ecological pathways by which vulnerability to climate change is reduced can help harness the multiple benefits of working with nature in a warming world.