Earth System

Earth system

The Earth is made up of a series of components – the hydrosphere, atmosphere, lithosphere, and biosphere. These function as systems that are constantly interacting and adjusting to both internal and
external factors. It is the continuous alterations to these cycles that produce the environmental conditions that we experience. This section explores the key characteristics and dominant drivers of these Earth system cycles. Environmental science studies the interactions between the physical, chemical, and biological components of the environment, including their effects on all types of organisms. The earth system is itself an integrated system, but it can be subdivided into four main components, sub-systems or spheres: the geosphere, atmosphere, hydrosphere and biosphere. These components are also systems in their own right and they are tightly interconnected. The four main components of the earth system may be described briefly in the following way.

The atmosphere

The atmosphere is an envelope of gases surrounding the earth. When the sun’s radiation enters the atmosphere, some of that radiation is reflected back into space by clouds and dust, and some travels to the earth’s surface, where it is absorbed or reflected back to space by such reflective surfaces as ice, snow and water.

The earth also emits infrared radiation, which is thermal, or heat, radiation. Certain atmospheric gases do not allow this longer-wave, infrared radiation to escape; it bounces back to earth, where it raises the surface temperature. This is known as the greenhouse effect. Without the greenhouse effect, the earth would be much cooler; many forms of life would not exist. The gases that make up the atmosphere - including nitrogen, oxygen, argon, carbon dioxide, methane and ozone - regulate and balance the energy contained and released.

The biosphere

The biosphere is defined as the space on earth - within the atmosphere, the hydrosphere and the lithosphere - where life has developed. It consists of the soil and upper part of the earth’s crust, the lower layers of the atmosphere, and the hydrosphere.

The biosphere may be thought of as common ground shared by humans, plants, birds, fish, bacteria and wild and domesticated animals. All ecosystems are combined in the biosphere, which has a self-regulating capability. If changes in the biosphere occur, however - physical and chemical changes to which organisms cannot adapt - then the ability of these organisms to absorb substances, to grow, and to reproduce is affected.

The Hydrosphere

The oceans and other large bodies of water hold heat absorbed from solar radiation longer than land. Currents circulate this heat vertically, from the surface to deeper waters, and horizontally, from high to low latitudes and across the longitudes. When this heat is released, often at a great distance from where it was absorbed, its interaction with the atmosphere produces the daily and seasonal cycles and temperatures affecting local climatic conditions.

The Lithosphere

The land is also called the lithosphere, or the earth’s crust, which supports a wide variety of unique ecosystems, ranging from arid areas to tropical forests. Each ecosystem is composed of distinct plants, animals, soils and nutrients that form interdependent systems.

Over time, ecosystems change, both as plant and animal life evolve and with events such as drought and flooding. On a scale of thousands of years, ecosystems have changed with the earth’s glacial cycles, and the earth’s surface alters through earthquakes and volcanic activity.

The water (hydrological) cycles

The water resources of earth are continually being recycled, driven mainly by the force of gravity and by energy from the sun. Precipitation, in the form of rain or snow, is the major source of moisture for the earth’s hydrological systems, although fog and dew may be important in certain regions. Rain falling on the oceans evaporates, forming clouds that produce more rain; some of the rain that falls on the vegetation cover, bare ground or on lakes and rivers also evaporates.

Water that enters the ground is either absorbed by plants’ root systems, or it percolates down through the soil to reappear later in seepage to streams and rivers, lakes, or oceans. Water may spend hundreds or even thousands of years in the ground.

How do the Earth's spheres interact?

All the spheres in the system interconnect and overlap. No sphere works on its own. Consider this diagram below.

These spheres are closely connected. For example, many birds (biosphere) fly through the air (atmosphere), while water (hydrosphere) often flows through the soil (lithosphere). In fact, the spheres are so closely connected that a change in one sphere often results in a change in one or more of the other spheres. Such changes that take place within an ecosystem are referred to as events.

Events can occur naturally, such as an earthquake or a hurricane, or they can be caused by humans, such as an oil spill or air pollution. An event can cause changes to occur in one or more of the spheres, and/or an event can be the effect of changes in one or more of Earth's four spheres. This two-way cause and effect relationship between an event and a sphere is called an interaction. Interactions also occur among the spheres; for example, a change in the atmosphere can cause a change in the hydrosphere, and vice versa.

Hydrosphere and the atmosphere - Evaporation from the hydrosphere provides the medium for cloud and rain formation in the atmosphere. The atmosphere brings back rainwater to the hydrosphere.

Geosphere and hydrosphere - Water provides the moisture and medium for weathering and erosion of rocks on in the geosphere. The geosphere, in turn, provides the platform for ice melts and water bodies to flow back into the oceans.

Atmosphere and geosphere - The atmosphere provides the geosphere with heat and energy needed for rock breakdown and erosion. The geosphere, in turn, reflects the sun's energy back into the atmosphere.

The biosphere receives gases, heat, and sunlight (energy) from the atmosphere. It receives water from the hydrosphere and a living medium from the geosphere

Impacts of earths system on the environment and human life

Flooding

Hydrosphere: is more than the cause of a flood, floods can also damage waterways such as rivers, lakes, and stream banks. Water can erode the rocks in the geosphere. The water will eventually go into the ocean, if it is through the sewers or in the process of evaporation so the hydrosphere can get polluted via plastic, metal, and other pollutants in the roads and sewage system. The hydrosphere is the sphere most affected by the event of a flood. Floods are caused by an earthquake in the hydrosphere, putting it at the top of the list for the spheres that are most affected.

Atmosphere: There is no significant change in the atmosphere during a flood. The only changes include increased chances of humidity in the atmosphere, and the evaporation of water into the atmosphere is much higher. There are no other events (specific to a flood) that happen in the atmosphere.

Geosphere: Floods affect the geosphere by destroying and eroding rocks and minerals. The water can break down easily dissolving substances in the minerals and rocks. The oil in the geosphere can also leak into the ocean. The flood could knock debris into the pipes, causing leakage into the water.

Biosphere: A flood effects the Biosphere by killing lots of animals, people, and plants. A few other affects that have not already been listed are that the event of a flood can make fish and other small marine animals thrive on land for the time the flood lasts.

Figure 1 Flooding

Global warming

Atmospheric methane, released from landfills, cattle and fermenting rice paddies, has increased with population growth. The build-up of these greenhouse gases may enhance the natural greenhouse effect and may result in additional warming of the earth’s surface, or global warming. If warming occurs as some scientists predict, the results might include a rise in the sea level, changes in climate, changes in ecosystems, and impacts on public health. The concentration of carbon dioxide in the atmosphere has increased nearly 25 percent since the onset of industrialization in the 18th century. To meet the world’s energy needs, the burning of fossil fuels - such as coal, wood and petroleum - frees carbon to join with oxygen in the atmosphere. Deforestation, the destruction of forests by burning or over-logging

Volcanic eruptions

Even though volcanoes are in specific places on Earth, their effects can be more widely distributed as gases, dust, and ash get into the atmosphere. Because of atmospheric circulation patterns, eruptions in the tropics can have an effect on the climate in both hemispheres while eruptions at mid or high latitudes only have impact the hemisphere they are within.

Atmosphere: Gases surrounding a celestial body make up its atmosphere. For short term speaking, when the volcano eruption, all the ash particles would throw up into the atmosphere. The volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operation temperature.

Hydrosphere: The part of the earth composed of water id called the hydrosphere. Volcanoes can affect the hydrosphere through the eruption, the lava and volcanic ash could cause the air pollution also through the raining go in to the water cycle ad pollute the water as well. Also, the ocean’s water temperature will rise.

Biosphere: The volcano eruption could kill the plants and the animals live nearby because of the hot lava and poisonous gases. Therefore, the raining water which contains the volcano ash could influence the plants growth in long term.

Lithosphere: The earth’s crust and the upper layer of its mantle make up the system call lithosphere. The force due to the eruption can change, destroy or create the new type of rock and landform such as igneous rocks.  Volcanic eruption often happens near the boundaries of tectonic plates. 

Figure 2 Volcanic eruptions

Ozone depletion

 Many forms of life will be affected as the ozone layer thins and more ultraviolet light reaches the earth. In humans, skin cancer and diseases of the eyes and immune systems are expected to increase. Ultraviolet radiation can penetrate the oceans’ surface, damaging fish and the phytoplankton base of the food chain, possibly impacting significantly on fish-eating populations. Ozone, a rare form of oxygen, is concentrated in the upper atmosphere or ozonosphere, located 11 to 24 km above the earth. This ozone layer, which protects life from the damaging rays of the sun, is being thinned by the release of chlorofluorocarbons (CFCs), chemicals used in refrigeration, foam products and aerosol propellants.

Landslides

Landslides involve fracturing of the lithosphere ranging from microscopic rock fragmentation to giant submarine slope failures, thus spanning more than 26 orders of magnitude in volume. Here I synthesize major rate constraints on landslide distribution, size, and impacts that help gauge their relevance in the Earth system with a focus on the lithosphere, the hydrosphere, and the biosphere.

Hydrosphere: Imaging a large cliff with a river at the bottom that's been there for hundreds of years, and through erosion the cliff now sticks out over the water by several meters. What would happen if the weight of the cliff edge became too great for the cliff to withstand? It falls, and sometimes the fall of these large rocks can be devastating to the ecology. These rock falls can cause the river to be blocked, destroying entire ecosystems and in some occasions cause tsunamis that drag land dwellers to their deaths.

Lithosphere: Landslides involve fracturing of the lithosphere on several spatial scales. The lower bound is set by the dynamic fragmentation of rock particles down to sub-millimeter scale during the motion of large bedrock landslides, a process that resembles catastasis caused by tectonic fault rupture.

Hydrosphere: Rapid delivery of landslide debris to rivers causes sediment pulses or waves that alter channel geometry, fluvial hydraulics, sediment caliber, and flood frequency. Some of the highest reported fluvial sediment yields have occurred in the wake of regional landslide episodes triggered by earthquakes, rainstorms, or a sequence of both.

Biosphere: As was mentioned above, landslides can have devastating effects on all living creatures. They can destroy acres of forests in seconds, pulling down all life with them, crushing unsuspecting people below them, and forcing entire towns to move due to the sheer potential for devastation all large landslides have. A very recent example of a deadly landslide was in Oso, Washington, United States on March 22, 2014 which engulfed a rural neighborhood and killed 41 people.

Figure 3 Landslides

Air pollution

Air pollution inflicts further damage on land and water systems: on agricultural crops, forests, rivers and lakes, buildings and human health. Such airborne pollution damages crops and vegetation by injuring the plant tissue, which increases susceptibility to disease and drought. Human health also suffers when pollution damages respiratory tracts. Most of the world’s urban dwellers breathe polluted air at least part of the time.

Sulfur dioxide (SO2), a major pollutant, is a corrosive gas harmful to humans and the environment. The burning of fossil fuels, to generate electricity, is a key source of sulfur dioxide; in developing countries, burning coal and wood also contributes. Other air pollutants include nitrous oxides, carbon monoxide, carbon dioxide and lead from vehicle exhaust. In some countries, particulate matter such as dust, dirt and smoke cloud the air.

Earthquakes

Earthquakes can affect us in various ways, such as death and injury, disease, disruption to services and amenities and general disruption of people's everyday lives.

Biosphere: An earthquake can have effects on the biosphere such as killing people, animals, disrupting ecosystems, destroying plant life and crops. When the biosphere is disrupted by an earthquake, it can cause havoc between animals and people, causing panic and further destruction. During an earthquake,

Lithosphere: is affected by shaking, ground rupture, landslides, avalanches, fires, forests being destroyed and severe building damage. This damage will send governments and relief organizations into overdrive, therefore also having an effect on the biosphere aspect of an earthquake.

Atmosphere: is affected by gas emissions from ground release toxic gases that are released into it. Eventually, the toxic gases will have an effect on the biosphere as well, making the biosphere very exposed to most impacts of an earthquake.

Hydrosphere: Tsunamis are one of the main reasons the hydrosphere is affected by an earthquake. When a tsunami reaches land, it can have a widespread effect on the coast of New Zealand. Most of the coast of New Zealand is populated, making the chances of fatalities by a tsunami very high.

Figure 4 Earthquakes

Marine pollution 

Marine pollution can have major consequences: Human wastes contain disease-causing bacteria and viruses. Non degradable materials injure and kill marine mammals. The spread of hazardous chemicals may damage the marine ecosystem and accumulate in seafood. Due to their enormous volume, oceans are frequently used as disposal areas for human societies’ garbage. Raw sewage, consisting of human excreta and domestic wastes, is the major source of ocean pollution. Sewage, livestock waste and fertilizer runoff also make bodies of water over-rich in dissolved nutrients, a process called eutrophication; this phenomenon depletes the water of oxygen, killing fish and other marine life. Other causes of degradation: litter dumped from ships, petroleum spills, and the dumping of radioactive substances.

Figure 5 Marine pollution

Reference

Bogdan, Dennis (18 June 2018). "Comment - Better Way To Avoid Devastating Asteroids Needed?". The New York Times. Retrieved 26 November 2018.

 Staff (21 June 2018). "National Near-Earth Object Preparedness Strategy Action Plan" (PDF). White House. Retrieved 22 June 2018.

 Mandelbaum, Ryan F. (21 June 2018). "America Isn't Ready to Handle a Catastrophic Asteroid Impact, New Report Warns". Gizmodo. Retrieved 22 June 2018.

 Myhrvold, Nathan (22 May 2018). "An empirical examination of WISE/NEOWISE asteroid analysis and results". Icarus. 314: 64–97. Bibcode:2018Icar..314...64M. doi:10.1016/j.icarus.2018.05.004. Retrieved 22 June 2018.

 Chang, Kenneth (14 June 2018). "Asteroids and Adversaries: Challenging What NASA Knows About Space Rocks - Two years ago, NASA dismissed and mocked an amateur's criticisms of its asteroids database. Now Nathan Myhrvold is back, and his papers have passed peer review". The New York Times. Retrieved 22 June 2018.

 Chang, Kenneth (14 June 2018). "Asteroids and Adversaries: Challenging What NASA Knows About Space Rocks - Relevant Comments". The New York Times. Retrieved 22 June 2018.

 U.S.Congress (Spring 2013). "Threats From Space: a Review of U.S. Government Efforts to Track and mitigate Asteroids and Meteors (Part I and Part II) – Hearing Before the Committee on Science, Space, and Technology House of Representatives One Hundred Thirteenth Congress First Session" (PDF). United States Congress (Hearings held 19 March 2013 and 10 April 2013). p. 147. Retrieved 3 May 2014.

 Crater Analysis Techniques Working Group; Arvidson, R. E.; Boyce, J.; Chapman, C.; Cintala, M.; Fulchignoni, M.; Moore, H.; Neukum, G.; Schultz, P.; Soderblom, L.; Strom, R.; Woronow, A.; Young, R. (1979), "Standard Techniques for Presentation and Analysis of Crater Size-Frequency Data", Icarus, 37 (2): 467–474, Bibcode:1979Icar...37..467C, doi:10.1016/0019-1035(79)90009-5, hdl:2060/19780014063.

 Bostrom, Nick (March 2002), "Existential Risks: Analyzing Human Extinction Scenarios and Related Hazards", Journal of Evolution and Technology, 9

 Robert Marcus; H. Jay Melosh; Gareth Collins (2010). "Earth Impact Effects Program". Imperial College London / Purdue University. Retrieved 2013-02-04. (solution using 2600kg/m^3, 17km/s, 45 degrees)

 Robert Sanders (February 7, 2013). "New evidence comet or asteroid impact was last straw for dinosaurs". UC Berkeley News Center. Retrieved 2013-02-11.

 Rumpf, Clemens M.; Lewis, Hugh G.; Atkinson, Peter M. (2017-04-19). "Asteroid impact effects and their immediate hazards for human populations". Geophysical Research Letters. 44 (8): 3433–3440. arXiv:1703.07592. Bibcode:2017GeoRL..44.3433R. doi:10.1002/2017gl073191. ISSN 0094-8276.