The long-term response of Greenland’s peripheral glaciers to climate change is widely undocumented. Here we use historical aerial photographs and satellite imagery to document length fluctuations of >1,000 land-terminating peripheral glaciers in Greenland over more than a century. We find that their rate of retreat over the last two decades is double that of the twentieth century, indicating a ubiquitous transition into a new, accelerated state of downwasting.