Hemp Cannabis sativa L. with a THC content low enough to avoid intoxication " has walked beside humanity for at least 10 millennia. The plant's renaissance is ... a practical answer to converging crises in climate, resources, and rural economies. Hemp can be spun into linen-soft cloth, mixed into concrete"like blocks, brewed into nutty milk, pressed into nutritious oil, and refined into graphene"grade carbon nanosheets. It grows fast, sequesters more carbon per hectare than most forests, and asks for little more than sunlight, moderate rainfall, and room to stretch. Because every single part of the stalk, seed, leaf, and root can be transformed into something of value, hemp stands apart as a champion of circular design. Early drafts of the Declaration of Independence were [written on] linen-hemp blends. Hemp's reputation suffered only when petro-synthetic fibers and anti-cannabis laws converged in the 1930s. Eighty years later, reforms from Canada to Australia to continental Europe have reopened fields once taken from the crop. Field trials in Ukraine and Italy show hemp's phytoremediation power: the plant can bind or volatilize heavy metals such as cadmium and nickel while leaving fiber fractions safe for non-food applications. The plant synthesizes over a hundred other phytocannabinoids. Chief among them, CBD modulates serotonin receptors, calms epileptic seizures in Dravet syndrome, and shows promise in anxiety, pain, and inflammation trials.