The period from the mid-nineteenth century to the end of the century saw heightened interest in the harmful effects of deforestation on rain. There was growing fear that deforestation was turning prosperous lands into deserts, accompanied by efforts to conserve remaining forests or replant denuded lands. In India, Australia, New Zealand, South Africa, Russia, and the United States, the cry was raised: forests must be protected and managed for rain. These efforts followed prior concern in France and British island possessions. In this, forest conservationists advanced a need for government control of forests and used forest influences on rainfall as justification. Opponents, in turn, attacked the premise of forest influences on rainfall and decried the lack of evidence for climate deterioration. The ensuing debate was a narrative of misunderstanding, misuse of data, and hyperbole. It is this aspect of the forest–climate question, the so-called desiccation theory and its misuse to achieve policy goals, that has formed the historiography of the controversy, but beneath the rhetoric is found a fledgling knowledge of forest influences on climate that can be seen in today’s science.