The Roles of Water in Earth¡¯s Surface Processes Water continuously cycles among land, ocean, and atmosphere via transpiration, evaporation, condensation, and crystallization, and precipitation, as well asdownhill flows on land. o MS--ESS2-4: Develop a model to describe the cycling of water through Earth's systems driven by energy from the sun and the force of gravity. [Clarification Statement: Emphasis is on the ways water changes its state as it moves through the multiple pathways of the hydrologic cycle. Examples of models can be conceptual or physical.] [Assessment Boundary: A quantitative understanding of the latent heats of vaporization and fusion is not assessed.] Core Idea ESS3.A: Natural Resources Humans depend on Earth¡¯s land, ocean, atmosphere and biosphere for many different resources. Minerals, fresh water, and biosphere resources are limited, and many are no t renewable or replaceable over human lifetimes. These resources aredistributed unevenly around the planet as a result of past geologic processes. o MS- ESS3-4: Construct an argument supportedby evidence for how increases in human population and per-capital consumption ofnatural resources impact Earth's systems. [Clarification Statement: Examples of evidence include grade-appropriate databases on human populations and the rates of consumption of food and natural resources (such as freshwater, mineral, and energy). Examples of impacts can include changes to the appearance, composition, and structure of Earth¡¯s systems as well as the rates at which they change. The consequences of increases inhuman populations and consumption of natural resources are described by science, but science does not make the decisions for the actions society takes.]Background Information: Water is fundamental to life on Earth. Knowing where and how much rain or snow falls globally is vital to understanding how weather and climate impact both our environment and Earth¡¯s water and energy cycles, including effects on agriculture, fresh water availability and responses to natural disasters. The Global Precipitation Measurement (GPM) mission,launching in 2014, will help scientist to better understand how much rain and snow falls around the world. 1Most of the freshwater we use is from surface sources (such as rivers and lakes),and those bodies of water are replenished by rain. Although the Earth¡¯s surface has more than 70 percent water, only about 3 percent is fresh water and less than 1 percent is available for consumption. Therefore, freshwater is a scarce and valuable resource. Humans use it for almost everything ¨C agriculture, power generation, and personal needs. In the United States, we often take it for granted that we can turn on the faucet and have easy access to safe, clean water. However,many people in the world are not so lucky. Conserving our freshwater resources and monitoring our freshwater distribution are becoming very important issues.