Reticular chemistry, the chemistry of linking together molecules by strong bonds to make extended structures, has yielded metal-organic frameworks and covalent organic frameworks. Each of these classes of structures offers a diverse set of opportunities for using precision molecular chemistry to construct ultra-porous MOF and COF crystals capable of addressing challenges in clean air, clean energy and clean water. Progress in developing the intellectual and practical basis for making molecules into materials and integrating such materials into carbon capture and water capture machines will be presented.