Jannis - Environmental Management

A system can be defined as “a set of components functioning together as a whole”. • System view allows to isolate and investigate certain aspects more closely. • Given complexity of environment, engineers and scientists need to simplify to tractable size. Systems can include one or more physical compartments and/or non-physical parts such as the economy

Global warming Acid rain Changes in soil pH

The environment is only moderately integrated (“loosely connected”) greatly hinders our ability to observed, predict, and ultimately correct the unintended consequences of our actions.

Fundamentally, all environmental problems involve either depletion of sources (consumption) or pollution of sinks (production of waste). Sinks: Atmosphere - global warming, acid rain, urban smog Ocean - pollution Sources: Ocean - overfishing Rain forest - global warming, reduced biodiversity

1) Make observations 2) Ask a question 3) Gather existing information 4) Formulate a hypothesis 5) Collect and analyze data 6) Consult existing information 7) Discuss data and draw conclusions 8) Peer review 9) Publish

Into 4 spheres • the biosphere (living organisms of Earth) • the atmosphere (the gaseous envelope surrounding the planet) • the hydrosphere (the liquid water on the surface of Earth) and • the lithosphere (the stony or rocky matter composing the bulk of the surface of Earth)

Earth system is open to energy. Most energy flows from the sun and is often radiated back into space. For all practical purposes Earth is a closed system for matter. If we discount the relatively small amount of matter added from meteorites and other space debris, Earth contains all matter that it will ever have. Hydrosphere, lithosphere, atmosphere and biosphere can be further subdivided. For example the lithosphere can be divided into continental or oceanic crust, the pedosphere (outermost layer of Earth’s crust consisting of soil), asthenosphere (upper Earth mantle, below the lithosphere), and so on. These spheres are all interconnected and constantly exchanging materials.

Integration refers to the strength of the interactions among the parts of the system. For instance, the human body is a highly integrated system, whose cells are interdependent and in close communication. Complexity is often defined as how many kinds of parts a system has.

The next (future) stage of society has been called the post-industrial stage. What form post-industrial society will take is open to speculation and debate, but two possible alternatives have been proposed. One is a sustainable future where the human population stabilizes and technology becomes less environmentally harmful. The second alternative is overshoot, where the human population climbs so high and technology is so harmful that the environment is degraded to the point that relatively few people can be supported, at least with decent standard of living.

The moderate integration and high complexity of environmental systems. Integration results from connectedness so that resource depletion or pollution of one part of the environment can have cascading, or domino, effects into other parts. For example, burning sulfur-rich coal affects the atmosphere as air pollution, but it also affects the hydrosphere, when it falls as acid rain to acidify lakes. The biosphere is also affected because aquatic organisms in the lake can die due to the increased acidity of the lake water. The burning coal can even affect the lithosphere when the acid rain dissolves limestone and other alkaline rocks to form caves and sinkholes.

Due to its integration and complexity

A community of organisms that interact with one another and with their physical environment, including sunlight, rainfall, and soil nutrients. Organisms within an ecosystem tend to interact with one another to a greater extent than organisms between different ecosystems. Within each ecosystem there are habitats, which are defined as the place where a population of organisms lives. (Population is defined as a group of organisms of the same species living at the same place at the same time.)

Positive feedback occurs when part of a system responds to change in a way that magnifies the initial change. For example, evidence indicates that a slight increase in average global temperature can increase in the melting of glaciers and snow that reflect sunlight back into space. Instead of reflecting light, more of the Earth’s surface becomes available to absorb heat. In nontechnical terms, positive feedback is often referred to as a “snowball effect” or “vicious cycle”.

Population, affluence, and technology

Sunlight-consuming organisms. Primary producers are autotrophic. Since photosynthetic organisms obtain their carbon from inorganic sources, they are called photo-autotrophic.

Trophic is the term used to describe the level of nourishment.

Organisms that are aerobic survive in oxygen-rich environments and use oxygen as the terminal electron acceptor. Obligate aerobes can survive only in the presence of oxygen. Anoxic environments contain low concentrations (partial pressure) of oxygen. Here nitrate is usually the terminal electron acceptor. Anaerobic respiration can occur only in the absence of oxygen or nitrate. Here sulfate, carbon dioxide, and organic compounds that can be reduced serve as terminal electron acceptors.

Net primary production. NPP shows the rate of biomass production in a given ecosystem. Some ecosystems such as tropical forest of a high NPP, whereas others such as deserts and tundra have a lower NPP.

The ocean is the largest reservoir of carbon (85%). Photosynthesis is a major driving force in the carbon cycle. The ocean is a major sink of carbon. In shallow waters there is net consumption of carbon due to synthetic activity. In deeper waters there is net production of CO2 due to respiration and decay processes. Ocean circulation occurs over a long-time scale, the ocean takes up CO2 at a slower rate than produced by anthropogenic sources and its CO2 absorption capacity decreases due to increasing saturation.

Nitrogen enters lakes usually in the form of nitrate (NO3-) from rivers or groundwater. When taken up by algae, plants or phytoplankton, the nitrogen is chemically reduced to NH2-R and incorporated into organic compounds. When dead biomass undergoes decomposition, the organic nitrogen is ultimately released as ammonia (NH3), at normal pH values in the form of ammonium (NH4+). Ammonia from natural sources and other sources such as industrial waste and agricultural runoff (e.g. fertilizers and manure) is oxidized to nitrate (NO3-) by nitrifying bacteria (Nitrosomonas / Nitrobacter)

A large, naturally occurring community of flora and fauna occupying a major habitat, e.g. forest or tundra.

6CO2 + 6H2O + 2800 kJ energy from sun → C6H12O6 + 6O2 [in presence of chlorophyll]

Nitrosomonas and Nitrobacter

Step 1: 4NH4+ + 6O2 ↔ 4NO2- + 4H2O + 8H+ Step 2: 4NO2- + 2O2 ↔ 4NO3- Overall reaction: NH4+ + 2O2 ↔ NO3- + 2H+ + H2O