Climate models agree that semi-arid regions around the world are likely to experience increased rainfall variability and longer droughts in the coming decades. In regions dependent on agriculture, such changes threaten to aggravate existing food insecurity and economic underdevelopment, and to push migration to urban areas. In the Brazilian semi-arid region, the Sertao, farmers' vulnerability to climate-past, present, and future-stems from several factors, including low yielding production practices and reliance on scarce and seasonally variable water resources. Using interpolated local climate data, we show that, since 1962, in the Bacia do Jacuipe-one of the poorest regions in the Sertao of Bahia state-average temperatures have increased similar to 2 degrees C and rainfall has decreased similar to 350 mm. Over the same time period, average milk productivity-the main rural economic activity in the county-has fallen while in Brazil and in Bahia as a whole milk productivity has increased dramatically. This paper teases apart the drivers of climate vulnerability of the Bacia do Jacuipe in relation to the rest of Bahia. We then present the results of a suite of pilot projects by Adapta Sertao, a coalition of organizations working to improve the adaptive capacity of farmers living in the semi-arid region. By testing a number of different technologies and arrangements at the farm level, Adapta Sertao has shown that interventions focused on balanced animal diets and efficient irrigation systems can help reduce (but not eliminate) the dependence of production systems from climate. They are thus viable adaptation strategies that should be tested at a larger scale, with implications for semi-arid regions worldwide.