Ecology, from the Greek ‘oikos’ (‘house’), is a relatively new and integrative scientific discipline focused on understanding interactions among organisms and their environments, including the ‘food chains’ that connect carnivores, herbivores, and plants; the spatial patterns of plant and animal populations; and the biogeochemical fluxes (transformations or flow of materials) among organisms and their abiotic environments. (From The Anthropocene: A very Short Introduction.) . While energy is in plentiful supply from the sun that drives the water cycle and fuels the biosphere, the surface Earth system is nearly closed to materials. Thus to support a flourishing biosphere all the elements needed by life must be efficiently recycled within the Earth system.
In general, biogeochemical cycles describe the pathways along which organic and inorganic substances move and interact in the various compartments of our Earth. Globally combined, they can be looked upon as a complex and dynamic network of flows of matter and forces in the air-water-earthlife system. A biogeochemical cycle is a pathway by which a chemical element, such as carbon or nitrogen, or a compound, like water, moves through Earth's biosphere, atmosphere, hydrosphere and lithosphere. Researchers are discovering that biogeochemical cycles--whether the water cycle, the nitrogen cycle, the carbon cycle, or others--happen in concert with one another. Biogeochemical cycles are "coupled" to each other and to Earth's physical features. The biogeochemical cycling of carbon, water, and nitrogen are most critical to human well-being and the natural world.
Carbon is the major chemical constituent of most organic matter, from fossil fuels to the complex molecules (DNA and RNA) that control genetic reproduction in organisms. Carbon is stored on our planet as organic molecules in living and dead organisms found in the biosphere; as the gas carbon dioxide in the atmosphere; as organic matter in soils; in the lithosphere as fossil fuels and sedimentary rock deposits such as limestone, dolomite and chalk; and (5) in the oceans as dissolved atmospheric carbon dioxide and as calcium carbonate shells in marine organisms. Rising atmospheric CO2 concentrations in the twentieth century caused increases in temperature and started to alter other aspects of the global environment, including measurable decreases
Today the world's biggest carbon capture facility turned on. If it works, in one year it will capture three seconds worth of humanity's CO2 emissions... at incredible expense.
The water cycle is key to the ecosystem service of climate regulation as well as being an essential supporting service that impacts the function of all ecosystems. There are two major concerns regarding the water cycle: first, the need to balance rising human demand with the need to make our water use sustainable by reversing ecosystem damage from excess removal and pollution of water. Second, there is a need for a safe water supply in many parts of the world, which depends on reducing water pollution and improving water treatment facilities.
The Nitrogen cycle represents one of the most important nutrient cycles found in terrestrial ecosystems. Nitrogen is used by living organisms to produce a number of complex organic molecules. Despite its abundance in the atmosphere, nitrogen is often the most limiting nutrient for plant growth. The Haber-Bosch method for synthesizing Nitrogen bypassed the limitation of organic “fixing” and opened up the possibilities for expanding agriculture through the use of artificial fertilizers. This profound modification of one of the biogeochemical cycles can be considered a form of geoengineering.
There is no organism without an environment, but there is no environment without an organism. Organisms do not experience or fit into an environment, they construct it. (lewontin and levins “Organism and Environment”)
First, organisms juxtapose bits and pieces of the world and so determine what is relevant to them. Second, organisms remake the environment at all times and in all places. Third, organisms by their life activities modulate the statistical variation of external phenomena as they impinge on the organisms. inally, the very physical natures of the signals from the outer world become transduced by the organism as they are made part of its effective environment.
A consequence of the codetermination of the organism and its environment is that they co-evolve. “ One cannotmake a sensible environmental politics with the slogan "Save the Environment, first, because "the" environment does not exist and second because every species, not only the human species, is at every moment constructing and destroying the world it inhabits
One measure of the human oikos is the “ecological footprint”, defined as the amount of space required to meet all of the needs of an average person. It comprises the land used for habitation, fresh water, food production and delivery, personal transportation, communication, communication, governance, other public functions, medical support, burial, and entertainment.