The concurrent pressures of rising global temperatures, peace and the incidence of species decline and the emergence of infectious diseases represent an unprecedented planetary crisis. Intergovernmental reports have drawn attention to the escalating climate and biodiversity crises and their linkages, but the interactions between all three pressures have been largely overlooked. The non-linearities and the dampening and reinforcing interactions between pressures make considering the linkages essential to anticipating planetary challenges. In this review, we define and provide examples of causal pathways that link the three global pressures of climate change, biodiversity loss and infectious disease. The literature review and case studies show that the mechanisms between certain pairs of pressures are better understood than others and that the entire triad of interactions is rarely considered. ( Alaina Pfenning-Butterworth, PhD, Lauren B Buckley, PhD coll. , more on thelancet.com)