Between 2000 and 2020, the potential for glacial lake outburst floods (GLOFs) and the exposure and vulnerability of downstream populations to them, have changed across the globe. The impact of these changes on the danger posed by GLOFs, as well as the relative importance of each factor, remains contentious, making the implementation of appropriate management and risk reduction strategies challenging. Here we show that globally, since 2000, the number of people exposed to GLOF impacts has increased by 3.2 million (27% increase), to a total of 15 million people as of 2020. The largest increase in GLOF danger occurred across the Andes, while only nine countries experienced a decrease in GLOF danger, most notably in Nepal and Kyrgyzstan. Importantly, contrary to the notion presented in current research, we find the changes in the threat from GLOFs have not been universally driven by either lake change, exposed population, or vulnerability; instead, the primary driver varies both at regional- and national-scales. Further, we show that vulnerability to GLOF impacts has declined almost everywhere, but this decline has been insufficient to offset the combined growth in the number and area of glacial lakes and downstream exposure. We highlight the Andes as a global hotspot for high, and rapidly increasing, contemporary GLOF danger, and suggest the region be targeted for further research. Critically, we show that mitigating GLOF impacts will require bespoke solutions depending on the relative impact of lake conditions, exposure and vulnerability on changing GLOF danger.