Earth’s Ecosystems: Understanding Our Planet’s Life Systems
Earth as a Living System: Understanding Our Finite Resources
Earth is a living system, or ecosystem, characterized as finite. Land is finite in space and its resources are limited in terms of sustainability. It is composed of:
- Hydrosphere: 97% saltwater, 2% ice, 1% freshwater
- Biogeochemical cycles: Water, carbon, nitrogen, phosphorus
- Hydrological cycle: Evaporation, condensation, precipitation, solidification
The third principle of land is that it is an open system with respect to energy flow. Biodiversity maintains the stability of the ecosystem. Cost-benefit analysis involves purchasing costed projects with the profits.
Key Environmental Concepts
- Greenhouse gases: Carbon dioxide, nitrous oxide, methane, ozone, water vapor
- PM10: Particles smaller than 10 microns
- Micrometer: Used to measure the dimensions of an object with high precision
- Greenhouse effect: A natural phenomenon that allows life to exist on Earth, where the planet acts as a greenhouse
- Primary pollutant: Emitted directly from a source into the air
- Secondary pollutant: Forms when other pollutants react in the atmosphere
- Atmospheric strata: Troposphere, mesosphere, thermosphere, exosphere
The General Law of Sustainable Forestry Development includes articles that define the systems provided by forest ecosystems and establish promotional bases. It also mentions the purchase of carbon credits through the Clean Development Mechanism (CDM) for sustainability. Natural resources are the result of years of biological evolution and ecological processes.
Human Impact and Sustainable Development
Anthropogenic: Intervention made by humans. Natural environments that have been altered.
Sustainable Development: Satisfying the needs of the present without compromising the future. Planet Earth, also called Gaia or the Blue Planet, involves processes for those who work the land. Energy flow and material cycling are both regulated by humans.
Earth’s Composition and Resources
Land as an existing system: The interaction of various ecosystems within it.
Lithosphere composition (30% of Earth’s surface):
- 30% Polar areas
- 32% Forests
- 25% Grasslands
- 11% Other surfaces
- 2% Human settlements
Classification of finite resources: Renewable and non-renewable.
Principles of Earth’s Systems
Homeostasis: When the biosphere self-regulates to maintain stable conditions or equilibrium.
Second Principle of Nature: Earth is a living system (biological and physical).
- Physical subsystem: Atmosphere (air), hydrosphere (water), lithosphere (land)
- Atmosphere: 78% nitrogen, 21% oxygen, 0.033% carbon dioxide and other greenhouse gases
- Hydrosphere: Oceans, seas, rivers, lakes, glaciers, raindrops
- Biological subsystem: Producers, consumers, and decomposers
- Biosphere: Interactions and abiotic processes occurring in the two subsystems that constitute an ecological system
Fourth Principle of Nature: Earth is a closed system subject to chemical flows. The most abundant element in living organisms is oxygen.
Sixth Principle of Nature: Ecosystem productivity and sustainability are finite, providing goods and services to humans.
Classification of environmental services: Regulation, provisioning, and support.
Seventh Principle of Nature: Limiting factors and carrying capacity are determinants in the population dynamics of species.
Sustainable Development Indicators
Agenda 21: A document that provides guidelines to promote sustainable development at global, national, and local levels.
Indicator: A perceptible sign of a trend or phenomenon that is not easily detectable.
Approach: A joint consideration of all items that allow for the organization of information.