Lab 1: Think Globally, Act Locally
Part A: Earth System Science
- Geosphere (Lithosphere): the solid Earth (rock materials on the surface and in Earth's interior layers) and soil. In this unit, we'll be concentrating only on the pedosphere, which is the outermost soil layer.
- Hydrosphere: all of Earth's bodies of water, including groundwater. The hydrosphere also includes the cryosphere, which is made up of the world's ice sheets and sea ice. In this unit, we'll be concentrating only on liquid water.
- Biosphere: all living things, from microbes to humans and everything in between.
- Atmosphere: the blanket of gas that surrounds the entire planet and extends to the edge of space. The atmosphere includes air, precipitation, clouds, and atmospheric aerosols (tiny particles suspended in the air).
Important functions of soil include:
- Providing a nutrient-rich medium for agriculture
- Producing and storing gases such as carbon dioxide
- Storing heat and water
- Providing a home for billions of plants, animals and microorganisms
- Filtering water and wastes
- Providing raw source materials for construction, medicine, art, makeup, etc.
- Decomposing wastes
- Providing a snapshot of geologic, climatic, biological, and human history
Oceans, which contain over 97% of Earth's water, help regulate global climate by absorbing large amounts of solar energy and circulating heat from the equator toward the poles through currents. Surface ocean currents are also affected by winds in the atmosphere. Energy from the wind gets transferred to the top layers of the ocean and helps circulate ocean water. Water is constantly moving between the hydrosphere, pedosphere, and atmosphere through plant transpiration (evaporation of water from plant leaves).
The biosphere also impacts climate. Plants use energy from the sun to undergo photosynthesis, a process that removes carbon dioxide from the atmosphere and adds oxygen. Animals (and humans) breathe in oxygen and exhale carbon dioxide. Human activities like burning fossil fuels or forests, also add greenhouse gases like carbon dioxide to the atmosphere. These gases can trap heat and keep it from escaping into space, thus contributing to an overall warming of the planet.
Connections between the biosphere and the hydrosphere and pedosphere are also extremely important. All living things need water to survive. Many plants rely on soil for valuable nutrients, and in turn, people and animals rely on those plants for food.
The atmosphere is more than just the air we breathe. It also includes wind, clouds, and precipitation. This thin layer of gas that envelops Earth, traps heat to keep us warm; protects us from harmful radiation; drives ocean currents that distribute heat and help regulate climate; brings rain to thirsty crops; and much more.
The atmosphere also includes aerosols, which are tiny particles suspended in the air. Typical examples of aerosols include the salt in sea spray, smoke from fires, smog, and dust. Aerosols can have negative impacts on human health. Changes in air quality due to increased concentrations of aerosols can worsen heart and lung diseases like asthma and bronchitis. Aerosols sometimes collect or get deposited in soil and bodies of water, which can lead to acidification and extensive ecosystem damage. The presence of aerosols in the atmosphere can also influence Earth's radiative balance and climate by scattering incoming sunlight, destroying ozone in the stratosphere, and increasing cloud formation.
Stop and Think1: Name something from each of the four spheres of the Earth system (pedosphere, hydrosphere, biosphere, atmosphere) that you interact with every day.
2: How do those things impact your life?