Water and carbon cycle systems and interconnectedness

Energy

The ability to do work

Flow/transfer

A form of linkage between one component and another that involves movement of energy or mass

Input

The addition of matter and/or energy into a system

Output

The results of a process within a system, the matter and/or energy it produces to leave the system

Store/component

A part of the system where energy/mass is stored or transformed

System

A set of interrelated components working together towards some kind of process. A series of stores/components that have flows/connections between them

Elements

The components of a system (inputs, outputs, stores etc.)

Attributes

The measured/perceived characteristics of the elements of a system (quantity/amount, size, temperature etc.)

Relationships

How the various elements of a system and their attributes work together to carry out some kind of process

Key characteristics of systems

Processes inputs in its components causing it to change in some sort of way and be released as an output. Tend to have a structure that lies within a boundary

Isolated system

A system with no interactions with anything outside the system boundary, no input/output of energy or matter, rare in nature, e.g. the universe, laboratory experiments

Closed system

A system with inputs and outputs of energy but not matter, e.g. the global water cycle, the global carbon cycle

Open systems

A system with inputs and outputs of energy and matter, e.g. most ecosystems

Cascading systems

A series of interconnected subsystems where the output of one becomes the input of the next, often move downward through nature, e.g. drainage basin

Drainage basin as a cascading system

Rain falls into the upper catchment (subsystem 1), is then transported downstream by the river (subsystem 2), and then deposited in a coastal zone (subsystem 3)

Dynamic equilibrium

When there is a balance between the inputs and outputs of a system over time so that stores remain the same. Generally made possible by negative feedback loops reacting to change in inputs

Positive feedback

When the effects of an action are amplified or multiplied by secondary effects

Example of positive feedback

Warmer atmospheric temperatures causing permafrost to melt and release greenhouse gases, further increasing atmospheric temperatures

Negative feedback

When the effects of an action are nullified by its secondary effects

Example of negative feedback

Increased atmospheric CO2 stimulates plant growth, leading to higher rates of photosynthesis, removing more CO2 from the atmosphere

Greenhouse gas

Characteristic of water vapour that means as atmospheric warming occurs and evaporation increases, a wetter atmosphere occurs with more water vapour creating a positive feedback loop due to this characteristic

Time lag (of many years/decades)

Relationship between increased atmospheric CO2 and global warming because oceans absorb most of the heat and take time to warm up

At least 0.6

Amount that Earth’s temperature is guaranteed to increase by due to CO2 already in the atmosphere and its time lag for impacting global warming

Tundra (permafrost)

Frozen ground that when warmed, is melted causing emission of stored CO2 and methane into the atmosphere and a positive feedback loop of further warming

Methods used to mitigate climate change

Carbon sequestration, improved vehicle fuel efficiency, increased use of renewable or nuclear energy, improved aviation industry, changing rural land use (afforestation, agricultural methods etc.), improved waste management, improved building design (insulation, green roofs, ventilation etc.)

90

Percentage of CO2 emissions from power plants that CCS is able to capture by separating CO2 from gases produced and storing them

Changing rural land use to mitigate climate change

Protecting existing forests, reforestation/afforestation, improving soil carbon storage through: avoiding overgrazing of livestock, revegetation, mulching etc.