Earth’s Spheres and Geological Activity:
– Earth science recognizes four spheres: lithosphere, hydrosphere, atmosphere, and biosphere.
– Some scientists include cryosphere and pedosphere as part of Earth’s spheres.
– Earth’s crust is distinct from the mantle and is involved in plate tectonics.
– Volcanoes form from subducted crust material or rising mantle.
– Magma cooling and solidifying create solid rock in the lithosphere.
– The mantle is heated by radioactive decay and is in rheic convection.
Water Bodies and Human Impact:
– Most water is found in natural bodies of water like oceans, lakes, and rivers.
– Coral reefs harbor significant marine biodiversity.
– Oceans cover about 71% of the Earth’s surface and are interconnected saltwater bodies.
– Lakes are localized bodies of water found in various regions.
– Human impacts on water include modifying rivers, urbanization affecting water levels, and deforestation leading to pollution.
Atmosphere, Climate, and Weather:
– Earth’s atmosphere consists of nitrogen, oxygen, argon, and trace gases.
– Greenhouse gases like carbon dioxide play a role in climate regulation.
– Layers of the atmosphere include the exosphere, thermosphere, mesosphere, stratosphere, and troposphere.
– Weather phenomena occur in the troposphere and are influenced by various factors.
– Climate examines long-term atmospheric conditions, while weather refers to day-to-day variations.
Global Warming and Climate Change Efforts:
– Glaciers are retreating due to global warming, impacting habitats and wildlife.
– Efforts focus on mitigating greenhouse gases, stabilizing concentrations, and developing adaptive strategies.
– Collaborative efforts like the United Nations Framework Convention and Kyoto Protocol aim to address climate change.
– Changes in Earth’s orbit historically influenced solar energy distribution and long-term climate.
– Climate is classified based on temperature and precipitation ranges using systems like Köppen and Thornthwaite.
Life, Ecosystems, and Wilderness:
– Life on Earth dates back approximately 3.7 billion years, sharing fundamental molecular mechanisms.
– Ecosystems consist of biotic and abiotic factors, with interconnected relationships.
– Wilderness is defined as natural environments not significantly modified by humans.
– Biogeochemical cycles like water, oxygen, carbon, nitrogen, and phosphorus are vital for sustaining life.
– Challenges include environmental advocacy, renewable energy adoption, biodiversity preservation, and sustainable waste management.
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.