GEC

Demographic transition

4 stages: 1) high birth/high death, no increase 2) high birth/low death, fast increase 3) lower birth/low death, growth slowed 4) low birth/low death, slow growth

Stratospheric ozone

90% of ozone is in the stratosphere, 19-48 km above the surface of the planet in tropical regions.

Deforestation

Conversion from forest to other land cover type(s). This is the most important type of reduction in forest area; forests can be cleared by people and then converted to another use, such as agriculture or infrastructure.

Box Model

Depiction of reservoirs - it shows both the burden, the content of a specific element, and its transport path, the process or mechanism that moves materials in and out of a reservoir. Flux is the amount of material transferred from one reservoir to another per unit of time - source is flux of material in, and sink is flux of material out. The budget is a balance sheet of all sources and sinks.

Coupled systems

Eroded soils transported by rivers have created the great deltas of the world, and their deposition have transformed the boundaries of continents. Today, nutrient-rich soils are being degrades and their dispersal modified by human activities. E.g. the dam on the Nile that brings water to Egypt and Sudan - before the dam, yearly flooding brought nutrients to the valley that are now being replaced by expensive fertilizers. This may be affecting Egypt's sardine catch.

Flux

Flux refers to the amount of material transferred from one reservoir to another per unit of time. An example of this is the rate of transfer of water from the ocean surface to the atmosphere. Its density is the amount of material transferred per unit area per unit of time.

Steady state

If sources (flux of materials into a reservoir) and sinks (flux of materials out of a reservoir) balance and do not change with time, the reservoir is in steady state.

Pollution

Pollution is human-induced change in the distribution of atoms from one place on Earth to another.

Land cover

The attributes of the Earth's land surface and immediate subsurface, including biota, soil, topography, surface and groundwater, and human structures. This refers to all of the biophysical attributes of the earth's surface. Many classifications and legends confuse land cover with land use, which the purposes for which humans exploit land cover.

Residence time

The average amount of time that a particle spends in a particular system. This measurement varies directly with the amount of substance that is present in the system.

Fertility rate

The average number of children women will have in their lifetime.

Afforestation

The growth of forest where there was no forest in the past

Photochemical smog

The mix of natural and atmospheric chemicals with anthropogenic emissions derived mainly from fossil fuel burning produced in the presence of solar radiation. It leads to reddish, yellow-brown, and gray hazes in the sky. Brown air cities tend to come from relatively non-industrialized countries, from cars and powerplants; gray air cities come from industrialized countries, where smog generates in cold, wet climates. The word smog comes from smoke and fog combined. A product of smog is ozone

VOC

Volatile Organic Compounds, such as hydrocarbons and methane - they produce ozone by complex chemical reactions.

Stratosphere

the second major layer of Earth's atmosphere, just above the troposphere, and below the mesosphere

Systemic Global Change

The natural of global change has two forms - systemic and cumulative change. Systemic changes are those that operate at a global scale. An example of this is the greenhouse effect or other global changes in the climate brought about by atmospheric pollution. This is different from cumulative change, which accounts for the net effect of local changes that add up to produce change on a worldwide scale.

Infant mortality

The number of infant (one year of age or younger) deaths per 1000 live births.

Respiration

The physical and chemical process by which an organism supplies its cells and tissues with the oxygen needed for metabolism and releases carbon dioxide formed in the energy-producing reactions C6H12O6 + 6O2 --> 6 CO2 + 6H2O

Photosynthesis

The process of synthesis of complex organic materials, using sunlight as a source of energy and with the aid of chlorophyll and associated pigments 6CO2 + 6 H20 --> C6H12O6 + 6O2 carbon dioxide + water --> organic matter + oxygen

Perturbation

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Reservoir (box model)

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Minamata disease

A Japanese-based corporation dumped tons of mercury compounds into Minamata Bay, in a city consisting mostly of farmers and fisherman. The mercury affected people's diets bc they subsisted on fish from the bay. They developed symptoms of mercury poisoning and the illness became known as "". This is a major implication of water pollution!

Technosphere

A globe-girdling web of human artifacts, including buildings, machines, roads, and electronic devices that formed from the rapid development of technology through cultural evolution. The technosphere is a system composed of science, engineering, industry, and government. It represents a threat to the biosphere, but there is also a growing dependence of the biosphere, and its associated ecosystem services, on a properly functioning technosphere

Carbon storage in temperate vs tropical region and forests

Carbon is stored in biomass of forests and organic matter of soils. Forest help to keep the carbon cycle in balance and to overall sustain life. Temperate forests have thick top soil and nutrients are stored mainly in soil, whereas in tropical forests, nutrients are stored in the biomass

LUCC

Land Use and Cover Change. There are proximate and underlying causes. The transformation has a six-stage process that generally starts with a visionary capitalist trying to make money. He purchases land, imports workers, goes through boom and bust period, unemployed will then seek land for subsistence, and then they end up in forests which are generally more secure.

Birth rate

Number of live births per 1000 people, calculated as the ratio between births and individuals in a specified population and time. This is commonly expressed as the number of live births per hundred or per thousand capita yearly.

Life expectancy

Number of years that an individual is expected to live.

O3

O3 represents ozone, an important trace gas. 90% of ozone is found in the stratosphere. It has two main functions - it protects us against incoming UV radiation and it regulates the global temperature.

Persistent Change

Persistent change occurs steadily and in one direction (unidirectional). An example of this is the rate at which the earth rotates; it is slowing, and therefore the days are getting longer. There are three other types of change - rhythmic change, cyclical oscillations, and short-lived events. Rhythmic changes are periodic fluctuations that occur at regular and predictable intervals; cyclical oscillations are fluctuations that occur irregularly and with varying intensity; and short-lived events are sporadic in space and time, representing a deviation from "normal" conditions.

Population pyramid

Pyramid showing the age and sex structure of a population. The horizontal axis is generally the percent of total population or number of people, and the vertical axis usually reflects the age grouping or year of birth.

Reforestation

Regrowth (including replanting) of forests where there was forest before.

Rhythmic Change

Rhythmic changes are periodic fluctuations that occur at regular and predictable intervals. An example of this type of change is the revolution of the earth about the sun, which produces the different seasons. There are three other types of change - persistent change, cyclical oscillations, and short-lived events. Persistent changes are those that occur steadily and uni-directionally; cyclical oscillations are fluctuations that occur irregularly and with varying intensity; and short-lived events are sporadic in space and time, representing a deviation from "normal" conditions.

Short-Lived Events

Short-lived events last for the span of days or even seconds. They are sporadic in space and time, and they represent a deviation from "normal" conditions. They are hard to predict, like lightning or earthquakes. There are three other types of change - rhythmic change, persistent change, and cyclical oscillations. Rhythmic changes are periodic fluctuations that occur at regular and predictable intervals; persistent changes are those that occur steadily and uni-directionally; and cyclical oscillations are fluctuations that occur irregularly and with varying intensity.

Acid deposition

The deposition of acids from the atmosphere in precipitation that falls as rain, sleet, snow, fog, dew, and gases and particulates on the planetary surface. There are two principal airborne pollutant gases - sulfur oxides and nitrogen oxides. Deposition can be wet or dry, and the source can be natural or anthropogenic.

Cumulative Global Change

The natural of global change has two forms - cumulative and systemic. Cumulative change accounts for the net effect of local changes that add up to produce change on a worldwide scale. These changes have significant effects on global resources, like water. Because of the water cycle and movement of water from one place to another, pollution of a local water source affects the global source of water.

Hydrosphere

describes the combined mass of water found on, under, and over the surface of a planet.

Uniformitarianism

the assumption that the same natural laws and processes that operate in the universe now have always operated in the universe in the past and apply everywhere in the universe

Global Environmental Change

"Earth is viewed as a complex, evolving planet that is characterized by continuously interacting physical and biological change over a wide range of space and time scales."

Land use

The purposes for which humans exploit the land cover. This includes the arrangements, activities, and inputs people undertake in a certain land cover to produce, change or maintain it. Whereas land cover is all of the biophysical attributes of the Earth's land surface and subsurface - land use is the manner in which these attributes are manipulated. An example of land-use change in a forest may be the conversion of the land for grazing and agriculture for food production. These changes may result in deforestation and soil degradation.

Biogeochemical cycle

The transport and transformation of elements (substances) through Earth system (the various subsystems/geospheres). This is the movement and recycling of elements. Energy from the sun and radioactive decay drive these process. Humans have modified these cycles in a variety of ways, leading to chemical and physical changes. An example is the water cycle - water in the ocean evaporates, rains out, and returns via rivers and ground water flow thousands of times. Water pollution is a huge problem because pollutants produced in one area may contaminate areas far from their source bc of the movement/cycle.

Reasons to study GEC

There are many reasons we study Global Environment Change. 1. We study GEC because the environment is constantly changing. 2. These changes can impact the habitability of the planet - we see this in the loss of biodiversity but this may also affect future generations and what resources people have to sustain themselves. 3. In order to understand the current conditions of the earth, we have to look at the history of changes. 4. Humans have the potential to rival natural controls of environmental change. 5. We want to be able to predict future changes.

GEC and space and time scales

There are many ways to look at global environmental change. You can look at the local or regional or global level. You can look at how slow or fast it's changing. You can look at changes vs. variability - change implies unidirectional, whereas variability implies shifts about some mean position; you can also look at systems that exhibit both change and variability.

Causes of GEC

There are three causes of change. Predisposing factors - the features of the environment that make it vulnerable to stress. Inciting factors - stresses that trigger a change. Contributing factors - additional stresses which enhance the response. An example is a landslide in a valley that had/has trees. The predisposing factors are the topography and climate; the inciting factors are cutting down trees or torrential rain. The contributing factors are the health of the trees and the humans living there who shouldn't be.

Predisposing Factors

There are three main factors or causal forces for change. Predisposing factors are features of an environment that make it vulnerable to stress, such as its topography. Steep slopes, for example, may make an environment more susceptible to landslides. The other factors are inciting factors, which are stresses that trigger a change in the environment, and contributing factors, which are additional stresses that enhance a response. An example of the former is cutting down a tree, and an example of the latter is the health of the tree.

Ozone hole

There is a hole seen over the Antarctic every spring since 1977. There are minimum concentrations of ozone seen in the fall. The theory is that during the long months of polar darkness over Antarctica, atmospheric conditions are unusual and trap atmospheric chlorine, causing chemical reactions to take place that couldn't take place anywhere else. CFCs get trapped and combine with the chlorine. Since it's been discovered, the Montreal Protocol of 87 was best mitigating strategy.

Point source

These are the easily identified individual factory outlet pipe and sewage treatment plant outlets that pollute water. This contrasts with non-point sources, which are more difficult to pin down - they include deposition of airborne pollutants from cars and factory emissions, agricultural practices, and runoff/drainage from urban areas.

Proximate cause (for land cover change)

These are the immediate actions that originate from intended land use. They're direct causes, such as swidden agriculture or gold mining. These are much more obvious than the underlying/indirect causes, which are formed by a mix of social, political, economic variables that affect human-environment relations

Tropospheric ozone

This is a major product of smog. It is a pollutant that is harmful to plants, animals, and humans, and it acts as a greenhouse gas. Humans heavily impact the ozone cycle with industry/agriculture and emissions of CFCs.

Traffic congestion

a condition on road networks that occurs as use increases, and is characterized by slower speeds, longer trip times, and increased vehicular queueing. The impact traffic congestion has on the earth is that it causes wasted fuel, which increases air pollution and carbon dioxide emissions owing to increased idling, acceleration and braking.

Ecosphere

a planetary ecosystem consisting of the atmosphere, the geosphere (lithosphere), the hydrosphere, and the biosphere.