Earth’s Spheres and Processes:
– Earth science recognizes four main spheres: lithosphere, hydrosphere, atmosphere, and biosphere.
– Additional spheres may include cryosphere (ice) and pedosphere (soil).
– Disciplines like geography, geology, geophysics, and geodesy study Earth’s spheres using physics, chemistry, biology, and mathematics.
– Geological activity involves processes like plate tectonics, volcanoes, and mantle convection driven by radioactive decay.
– Water on Earth is primarily found in natural bodies like oceans, rivers, and lakes, playing a crucial role in the hydrological cycle.
Impact of Human Activities on the Natural Environment:
– Human activities impact water sources through modifications like dams and urbanization.
– Deforestation leads to water pollution and changes in riverside vegetation.
– Urbanization affects lake levels and groundwater conditions.
– Direct manipulation of rivers and impact of dams on fish migration are significant concerns.
– Efforts are focused on mitigation and adaptation strategies to address global warming and environmental degradation.
Atmosphere, Climate, and Weather:
– The atmosphere consists of layers like the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
– Greenhouse gases like carbon dioxide and methane contribute to global warming.
– Climate analysis involves temperature, humidity, pressure, wind, rainfall, and particle count over long periods.
– Weather refers to day-to-day atmospheric conditions influenced by temperature and moisture variations.
– Efforts to address climate change include international treaties, protocols, and scientific collaborations.
Life on Earth and Ecosystems:
– Life on Earth has existed for approximately 3.7 billion years, characterized by organization, metabolism, growth, adaptation, and reproduction.
– Ecosystems consist of biotic and abiotic factors interacting in a specific area.
– Greater species diversity in ecosystems leads to higher resilience.
– Biogeochemical cycles like water, oxygen, carbon, nitrogen, and phosphorus are vital for sustaining life on Earth.
– Wilderness areas are essential for species survival, ecological studies, conservation, and recreation.
Conservation Efforts and Challenges:
– Environmentalism advocates for protecting nature, eliminating pollution, preserving biodiversity, and halting global warming.
– Conservation efforts include understanding Earth’s processes, guiding sustainable practices, and raising awareness through environmental science.
– Challenges involve shifting to renewable energy, sustainable resource use, reducing consumption, and addressing human population growth.
– Criticism of environmental movements stems from cultural diversity and varying perspectives on the concept of environment and environmentalism.
– Research, studies, and continuous efforts are crucial to protect and preserve the natural environment.
The natural environment or natural world encompasses all living and non-living things occurring naturally, meaning in this case not artificial. The term is most often applied to Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity. The concept of the natural environment can be distinguished as components:
- Complete ecological units that function as natural systems without massive civilized human intervention, including all vegetation, microorganisms, soil, rocks, the atmosphere, and natural phenomena that occur within their boundaries and their nature.
- Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air, water, and climate, as well as energy, radiation, electric charge, and magnetism, not originating from civilized human actions.
In contrast to the natural environment is the built environment. Built environments are where humans have fundamentally transformed landscapes such as urban settings and agricultural land conversion, the natural environment is greatly changed into a simplified human environment. Even acts which seem less extreme, such as building a mud hut or a photovoltaic system in the desert, the modified environment becomes an artificial one. Though many animals build things to provide a better environment for themselves, they are not human, hence beaver dams, and the works of mound-building termites, are thought of as natural.
People cannot find absolutely natural environments on Earth, and naturalness usually varies in a continuum, from 100% natural in one extreme to 0% natural in the other. The massive environmental changes of humanity in the Anthropocene have fundamentally effected all natural environments: including from climate change, biodiversity loss and pollution from plastic and other chemicals in the air and water. More precisely, we can consider the different aspects or components of an environment, and see that their degree of naturalness is not uniform. If, for instance, in an agricultural field, the mineralogic composition and the structure of its soil are similar to those of an undisturbed forest soil, but the structure is quite different.
