In the second half of the twentieth century, natural gas became a crucial energy source for Iranian society. Under both the monarchy and the Islamic Republic, the exploitation of gas, long pursued by Iranian officials in the face of opposition from the international oil firms that operated their country’s petroleum fields, transformed Iranian society through the provision of vast quantities of cheap fuel and the rapid industrialization and modernization policies it furthered. In the 1960s and 1970s, new infrastructures to support natural gas distribution began to stretch their way across the Iranian landscape. But these pipelines, refineries, and gas terminals—and the intensified energy consumption they enabled—were not the only manifestations of Iranians’ utilization of their country’s extensive gas reserves. Just as important, natural gas became an essential ingredient to Iranian efforts to push the biological limits of their society, engendering new relations between Iranians and the interwoven ecologies that surrounded, interpenetrated, and underlay their communities. Focusing on early efforts to use natural gas resources to preempt deforestation as well as produce agricultural fertilizers and pesticides, I argue that gas was embraced as a way for Iranians to manage biological life within their country. As early as the 1940s, natural gas was seen as a feedstock for a new petrochemical industry that promised to jumpstart modern agriculture in Iran and make green large swaths of arid land in the country’s south. By the 1960s, gas was being used to produce nitrogen fertilizers on an industrial scale, making chemical agriculture much more accessible to Iran’s farmers and enabling the extensive cash cropping of sugar in the country’s southwestern regions. Through the manufacture of pesticides from natural gas, the same petrochemical industry held out the possibility of boosting agricultural productivity further still as well as improving human health through the suppression of unwanted life. Even in its role as a source of energy, gas was welcomed as a preserver of life, bringing the hope that Iran’s forests might be saved from the axes of those seeking to produce charcoal for domestic fuel consumption. Going beyond accounts of Iranian petroleum that emphasize its role as a source of energy for the world and the geopolitical machinations that ensued, this paper explores how the carbon remains of the ancient dead were employed to enact new visions for Iranian life, ultimately working to refigure it around forested holidays, desertification, changed diets, and metabolic syndrome.