Planetary Boundaries

Definitions

• A
• B
• C
• D
• E
• F
• G
• H
• I
• J
• K
• L
• M
• N
• O
• P
• Q
• R
• S
• T
• U
• V
• W
• X
• Y
• Z

A

albedo

A measure of how much light is reflected off a surface back into space rather than being absorbed. For example, ice has a high albedo.

aragonite

A mineral consisting of calcium carbonate (CaCO₃) that is produced by corals and other marine life.(Rockstrom et al., 2009)

B

biomagnification

The processes where toxins in an organism increase up the food chain.

biosphere

The regions of the earth occupied by living organisms.

blue water

The water from surface and groundwater reservoirs like rivers, lakes, and dams.(Rockstrom et al., 2009)

C

carbonate

An ion which contains one carbon and three oxygen atoms (CO₃^2-)

CFC

CFC stands for chlorofluorocarbons which are gaseous compounds that contain carbon, chlorine, fluorine, and sometimes hydrogen. They are typically used in refrigerants and aerosol propellants. (Wikipedia 2022)

comprehensive

Refers to a control variable`s ability to capture the planetary scale of the problem. The control variable must indicate the entirety of the potential impacts of novel entities. (Persson et al., 2022)

concentration

The amount of a substance per unit volume. For example, seawater has about 35 grams of salt in every litre of seawater.

coral bleaching

When coral expel the algae leaving the coral bare and white. This happens in response to warmer temperatures and stress.

core process

In the Planetary Boundaries framework, core Earth-system processes represent the strongest indicators of planetary "health", in that they are strongly connected to all of the other processes.

D

destabilize

Cause a system to change in a way that is too large or sudden for the system to adapt to smoothly, if at all.

dissolved oxygen

The amount of oxygen dissolved in water. Usually measured in mg/L.

E

earth's energy balance

The difference between the energy that the earth receives from the sun and the energy earth released back into space.

eutrophication

The increase in the concentration of phosphorus, nitrogen, and other plant nutrients in aquatic ecosystems. These nutrients enter the ecosystem through runoff.

evapotranspiration

The process by which water moves from the earth’s surface into the atmosphere. It covers both evaporation (turning liquid into gas) and transpiration (loss of water in a plant through its leaves). (Wikipedia 2022)

F

feasible

Refers to how easily a control variable can be measured. (Persson et al., 2022)

feedback cycles

A circular relationship in a system where the causes and effects are connected to each other. These can be positive feedback cycles where the circular relationships causes the affects to be amplified or a negative feedback cycle where the response is reduced due to the circular relationship.

flow rate

How much material or energy is being moved, per unit time.

G

green water

Water that is held in soil and available to plants. This includes terrestrial precipitation, evaporation, and soil moisture.

I

intensity

The amount of energy that enters or leaves a surface per unit of time, per unit of surface area.

M

monocrop

A form of intensive agriculture where there is a planting of a single crop on a large area of land.

N

non-point source pollutant

A pollutant that does not have a single source that is easily identified.

P

persistent organic pollutant (POP)

Organic compounds that are resistant to environmental degradation. They are toxic chemicals that affect human health and the environment.(Wikipedia 2022)

pollution

Substances released into the Earth system through human activity that adversely impact Earth system processes. Examples include: plastics, CFCs, persistent organic pollutants, endocrine disruptors, heavy metals, nuclear wastes, and many others. (Rockström et al., 2009)

process

In this context, a process includes the flows, changes, and influences of certain materials and energy.

R

relative

Describes if a control variable can be strongly linked to effects on other Earth systems. (Persson et al., 2022)

resilience

The capacity for a system to adapt to changes and continue to develop or remain healthy.

S

saturation state

A measure of the potential for a mineral to form or dissolve. (Wikipedia 2022)

solar radiation

The electromagnetic energy emitted by the sun.

speciation

Chemical speciation refers to the distribution of an element amongst chemical forms in a system.

stratosphere

The second "layer" of the atmosphere, between roughly 10 km and 50 km above the ground, which includes the "cruising altitude" of most jet aircraft. It contains the ozone layer.