HESS Opinions “Climate, hydrology, energy, water: recognizing uncertainty and seeking sustainability”

Since 1990 extensive funds have been spent on research in climate change. Although Earth Sciences, including climatology and hydrology, have benefited significantly, progress has proved incommensurate with the effort and funds, perhaps because these disciplines were perceived as “tools” subservient to the needs of the cli5 mate change enterprise rather than autonomous sciences. At the same time, research was misleadingly focused more on the “symptom”, i.e. the emission of greenhouse gases, than on the “illness”, i.e. the unsustainability of fossil fuel-based energy production. There is a real risk of severe socioeconomic crisis in the not-too-distant future, unless energy saving and use of renewables become the norm. A framework for drastic 10 change is needed, in which water plays a central role, due to its unique link to all forms of renewable energy, from production (hydro, wave) to storage (for time-varying wind and solar sources), to biofuel production (irrigation). The expanded role of water should be considered in parallel to usual roles in domestic, agricultural and industrial use. Hydrology, the science of water on Earth, must reinvent itself within this new paradigm 15 and radically rethink its fundaments, which are unjustifiably trapped in the 19th-century myths of deterministic theories and the zeal to eliminate uncertainty. Guidance is offered by modern statistical and quantum physics, revealing the intrinsic character of uncertainty/entropy in nature, thus advancing towards a new understanding and modelling of physical processes, which is fundamental for the effective use of renewable 20 energy and water resources. 1 Climate and climate research Since 1990, major funds adding up to billions of euro have been spent in Europe and worldwide on research into projected climate change, its impacts, and emerging vulnerabilities. Earth sciences including climatology and hydrology have played a cen25 tral role in this scene and benefited significantly. Technological advances in satellite