Understanding Earth’s Environment: Constituents, History, and Challenges
Understanding Our Environment
The environment encompasses everything around us, and we must strive to keep our cities, schools, homes, and all places we inhabit clean. This document presents an investigation into the environment.
Concept of the Environment
The environment is defined as a set of abiotic factors (solar energy, water, air, and soil) and biotic factors (living organisms) that together form the thin layer of the living biosphere called Earth, which is home to all living things.
Constituents of the Environment
The Earth’s environment is composed of several interconnected spheres:
- The Atmosphere: This gaseous mixture of nitrogen, oxygen, hydrogen, carbon dioxide, water vapor, other elements and compounds, and dust particles protects Earth from excessive ultraviolet radiation and enables life. Warmed by the sun and Earth’s radiant energy, the atmosphere circulates around the planet, modifying thermal differences.
- Water (Hydrosphere): Approximately 97% of Earth’s water is found in oceans, 2% is ice, and the remaining 1% is fresh water from rivers, lakes, groundwater, atmospheric humidity, and soil moisture.
- Soil (Lithosphere/Pedosphere): Soil is the thin mantle of matter that sustains life on Earth. It is a product of the interaction between climate, bedrock (such as glacial moraines and sedimentary rocks), and vegetation.
Living organisms, including humans, depend on all these constituents. Plants utilize water, carbon dioxide, and sunlight to convert raw materials into carbohydrates through photosynthesis. Animal life, in turn, depends on plants in a sequence of interconnected links known as a food web.
Earth’s Environmental History
Throughout its long history, Earth has changed gradually. Continental drift (the result of plate tectonics) separated land masses, oceans invaded and then receded, and mountains rose and eroded, depositing sediment along the coasts (see Geology). The climate heated up and cooled, and lifestyles appeared and disappeared, continually changing the environment.
The most recent major environmental events in Earth’s history occurred during the Quaternary period, specifically the Pleistocene epoch (between 1.64 million and 10,000 years ago), also known as the glacial period. The subtropical climate disappeared, changing the face of the Northern Hemisphere. Great ice sheets advanced and retreated four times in North America and three times in Europe, alternating between cold and temperate climates. This significantly influenced plant and animal life and, ultimately, gave rise to the climate we know today. Our current age is known as the postglacial or Holocene epoch.
Environmental Problems
Rapid technological progress after the Middle Ages led to the Industrial Revolution, which brought about the discovery, use, and intensive exploitation of fossil fuels and Earth’s mineral resources. It was with the Industrial Revolution that humans began to truly change the face of the planet, the nature of its atmosphere, and the quality of its water.
Today, the unprecedented demand from rapid human population growth and technological development is subjecting the environment to immense stress, producing an increasingly rapid decline in its quality and its ability to support life.