The purpose of this paper is to analyze the apocalyptic vision in Lord Byron’s poem “Darkness” as Anthropocene eco-anxiety. The poem was written in 1816, often called the ‘year without a summer,’ due to extreme weather from the Tambora volcano eruption the year before. The extreme weather, poor harvests, ensuing famine and social unrest are reflected in “Darkness”, Byron’s darkest poem, which describes an apocalypse. The ecological catastrophe of the sun’s extinction leads to the destruction of ecosystems, civilization and humanity, offering a grim vision of the impact of environmental disaster on the human psyche. The ecological anxiety of “Darkness” paralles the concept of ‘dark ecology’ in that it explores the interconnectedness of humans and the environment, and draws attention to the darker aspects of the impact of climate change and ecological crises on the planet and on humans. By vividly depicting the ecological anxiety stemming from the collapse of the natural world, “Darkness” demonstrates a deep concern about humanity’s unsustainable behaviour and its potential consequences for the environment. The eco-anxiety manifested in the poem thus provides a much-needed act of imagination in today’s ecological crisis, warning of the timeless consequences of environmental catastrophe.