For millennia, climate change has been the Earth’s pulse. When early humans started roaming our planet, they faced climatic challenges in the shape of icecaps expanding into what were once hospitable regions. At other times, droughts and weather extremes followed optimum temperatures, driving migrations and triggering famine and starvation. The geological record reveals that climatic crises respond to cyclical cosmic fluctuations which drive a complex and dynamic interplay involving the atmosphere, the oceans and the Earth. Humans exert a modest influence in this planetary game and have no better strategy but to adapt and learn from the past on how to succeed in a constantly-changing world. The study of historical climates offers a clue to understanding how past civilisations reacted to climatic crises, coping with changes or falling into oblivion. This lecture will illustrate examples of hydraulic civilisations of Southeast Asia (the Khmer, the Pyu of ancient Burma and the Arakanese of the Mrauk-U) that made water management their strategy for social and economic success during periods of climatic downturns. An analysis of past events will offer insights into our current challenges, beset by impending climatic crises of unpredictable and unprecedented consequences.