Most continental environments (e.g., soils, freshwaters) are naturally acidic (pH<7) due to respiration and oxidation reactions in biotic and abiotic systems. In the last 100 years, the acidity of many regions of the world has increased as a consequence of energy and food production. In the last 30 years, the phenomena and impacts of 'acid rain' have been extensively investigated in Europe, North America and Asia, This paper will give a brief historical overview of acid deposition, the impact that food and energy production have had on enhancing the acidity of the environment, and the important role that the International Conferences have had in advancing our understanding of acid rain and its effects. The paper will conclude a look towards the future.