The Importance of Water and Carbon to Life on Earth

This page discusses the critical roles that water and carbon play in supporting life on our planet.

Water's importance:

• Helps create thermal conditions on Earth
• Oceans moderate temperatures by absorbing and slowly releasing heat
• Clouds reflect incoming solar radiation, lowering surface temperatures
• Water vapor absorbs longwave radiation, maintaining Earth's average global temperatures

Carbon's importance:

• Forms the building blocks of life on Earth
• Available for use in the natural world and by humans
• Stored in various forms including carbonate rocks, sea water, atmosphere, and biosphere
• Basis for life in the form of large carbon-based molecules like proteins
• Serves as economic resources in the form of fossil fuels

Highlight: Water and carbon cycles are interconnected, cycling between land, oceans, and atmosphere through open and closed systems.

Definition: Open systems allow matter to enter or leave, while closed systems do not permit the exchange of matter with the surroundings.

The Processes of the Water Cycle

This page focuses on the specific processes within the water cycle, particularly precipitation and its effects on water movement and storage.

Water balance equation: Precipitation (P) = Evapotranspiration (E) + Streamflow (Q) ± Storage

Precipitation:

• Defined as water and ice falling from clouds (rain, snow, hail, sleet)
• Affects catchments (areas drained by rivers and tributaries)
• Intensity and duration influence water movement and potential flooding

Factors influencing water movement:

• Precipitation intensity: High intensity can lead to rapid overland flow into streams and rivers
• Duration: Prolonged precipitation can saturate soil, leading to overland flow and potential flooding
• River discharge: High discharge and flooding are common during concentrated precipitation in rainy seasons

Definition: Catchment - The area drained by a river and its tributaries, also known as a drainage basin.

Highlight: The intensity and duration of precipitation play crucial roles in determining water movement and the potential for flooding in a given area.

The Water and Carbon Cycles

This page provides an overview of the water and carbon cycles, explaining their global scale operations and the concept of open and closed systems.

Global water cycle components:

• Atmosphere
• Ocean
• Land

Water movement processes:

• Precipitation
• Evapotranspiration
• Run-off
• Groundwater flow

Carbon cycle processes:

• Photosynthesis
• Respiration
• Oxidation
• Weathering

Definition: A system is composed of parts that work together to perform a function.

Vocabulary:

• Closed system: A system where no matter enters or leaves
• Open system: A system where matter can enter or leave the surroundings

Example: The carbon and water cycles on a small scale, such as in a water basin or forest ecosystem, are open systems.

Highlight: The distribution and size of major stores in the carbon and water systems include the atmosphere, oceans, water bodies, ice (cryosphere), groundwater, soil, and vegetation.