The ecological crisis is the result of modernity's coloniality. The Moderns considered the Earth as 'natural resources' at their disposal. Their colonial vision of nature was complemented by that of nonmodern cultures like Byzantium and pre-Columbian America as passive or primitive, respectively. For the Moderns, the Byzantines were the 'librarians of humanity,' an inert repository of Greco-Roman knowledge, unable to produce their own. Byzantium's inertia was matched by that of nature, both reservoirs of epistemic and material resources. Thanks to those “librarians,” the supposedly inexhaustible supply of natural resources, and the epistemic and material riches of indigenous America, the Moderns believed they were inaugurating an epoch of intellectual maturity and infinite growth. Today, the enduring negative view of Byzantium and the ecological crisis confirm that we remain entangled in modernity's coloniality. We should decolonize both history and nature. To mitigate humanity's existential threat, modernity must be rethought and overcome.