The natural sciences that allow us to understand the environment are at the heart of developing strategies to adapt to, survive, and thrive as climate changes. Water is at the heart of many of the most complex problems in climate sciences: understanding the behavior of clouds in a warmer world, how land ecosystems mediate evolving rainfall patterns, and when weather patterns trigger decline of the polar ice sheets. The behavior of these macrophysical problems can be interrogated by knowing the details of the microscopic properties of water: small variations in the abundance of naturally occurring heavy oxygen and hydrogen isotopes in water. Utilizing the stable isotope chemistry requires integrating many scientific disciplines and linking disparate areas of theoretical, observational and modeling techniques. I give examples of the coupling of carbon and water cycles in forests, and in the interaction of forest fire and clouds. I discuss the importance of the sciences which form the kernel that enable evidence-based decision making, and the opportunities for leveraging physical sciences to empower communities to shape their responses to climate change.