MOD3: Environmental Factors

• The Earth System consists of 4 components: atmosphere, hydrosphere, geosphere, and biosphere
• Matter cycles between these system components, with the movement of matter described as the rate of flow or flux of materials moving into and out of reservoirs
• An example of matter movement is the circulation of water into the oceans from various sources, balanced by evaporation to the atmosphere
• During the last ice age, frozen precipitation trapped in ice sheets caused a significant drop in sea level
• The rate of melting glaciers on continents has intensified, leading to a rise in global sea levels
• The Earth system is characterized by the flow of matter through reservoirs in each major sphere
• Carbon dioxide naturally flows into the atmosphere from the decomposition of organic materials and forest fires
• The Keeling Curve records the steady increase of carbon dioxide in the atmosphere
• Carbon dioxide and other gases are exchanged between the atmosphere and the ocean
• Carbon becomes part of a carbonate ion that combines with calcium to form calcite in the biosphere
• Limestone forms when organisms die, are buried, and compacted into rock layers on the seafloor
• The geosphere includes continents, ocean floors, rocks, minerals in Earth's crust, mantle, and core
• Most rocks remain in the geosphere for millions of years, making it Earth's largest carbon reservoir
• The biosphere consists of all living organisms on the planet, with more carbon stored in the geosphere's fossil fuel reserves than in the biosphere
• Plants take in carbon dioxide through photosynthesis to form carbohydrates for growth
• Soils contain decaying plant material and living biomass of microbes that help break down dead plant matter
• Changes in one Earth system component lead to changes in other parts of the system due to feedback loops
• Human activities have significantly increased the flow of carbon among Earth system components
• To halt the increase of carbon in the atmosphere, human production of carbon needs to be reduced or carbon uptake in other Earth system components increased
• Feedback loops are mechanisms formed by the links between living and nonliving things that build resilience in ecosystems
• Positive feedback amplifies a particular effect or change from previous conditions, essential in ecosystem buildup
• Negative feedback diminishes or counteracts changes in an ecosystem to maintain a stable balance
• An example of positive feedback is the enrichment of soil with humus from dead plants, promoting plant growth
• Negative feedback in predator-prey relationships maintains a long-term equilibrium in ecosystems
• Feedback processes can be counterintuitive compared to linear cause and effect scenarios
• Feedback loops are the product of links in the loop, with the addition, removal, or weakening of links affecting the feedback force
• Natural communities consist of networks of interactions, with feedback loops often occurring through longer chains
• Feedback loops in ecological systems create regular patterns, similar to multiple instruments coming together to create a complex but harmonious piece of music
• Negative feedbacks in ecological systems keep positive feedbacks in check, similar to drums maintaining a rhythm
• Different habitats like ocean environments, desert ecosystems, and tropical rainforests have unique characteristics in terms of feedback loops and interactions
• Earth's Climate System components include the atmosphere, hydrosphere, biosphere, and geosphere
• The atmosphere on Earth is dominated by nitrogen and oxygen, with important greenhouse gases like water vapor, carbon dioxide, methane, nitrous oxide, and ozone
• Aerosols in the atmosphere play a role in reflecting or absorbing solar radiation, affecting Earth's climate
• Water reservoirs on Earth include oceans, ice, and water droplets or ice crystals in clouds in the atmosphere
• Life is a crucial component of the climate system, exchanging carbon and oxygen with the atmosphere and cycling nutrients like nitrate and phosphate
• Vegetation on land can either absorb or reflect incoming solar radiation
• Dark-colored forests absorb incoming solar radiation
• Grasslands and dry desert ecosystems, as well as oceans, reflect incoming solar radiation
• Marine organisms build tiny shells that chemically buffer the ocean’s pH to prevent abrupt changes
• Oceans are becoming more acidic, surpassing their buffering capacity