Foreword: International Space Science Institute (ISSI) Workshop on the Earth's Hydrological Cycle.

The article offers information on importance of hydrological cycle of the Earth's system. Topics discussed include atmospheric water vapor as crucial in forming the Earth's climate zones by interacting with the atmospheric circulation, International Space Science Institute's (ISSI) workshop on hydrological cycle held from February 6-10, 2012 in Bern, Switzerland and adverse effects of water stress in the world's fourth largest lake the Aral Sea in Uzbekistan.