BIO329: Climate Change Biology - Lecture 1: The Climate System

These vocabulary flashcards cover the fundamental definitions, physical properties, and system dynamics of Earth's climate system as presented in BIO329 Lecture 1.

Weather

The short term shifts and fluctuations in the state of the atmosphere around us, including temperature, wind, precipitation, clouds, and storms.

Climate

The average weather in an area over a long period of time, measured in terms of its mean and variability.

Climate change

A statistically significant deviation from the climate’s mean state or variability that persists over time.

Heat

The energy that drives climate processes, mainly originating from solar radiation and geothermal energy.

Water

The medium that transports and redistributes heat energy throughout the global climate system.

Solar constant ($S$)

The measure of solar energy reaching Earth’s surface, which is approximately $1.37\,kW\,m^{-2}$.

Albedo ($a$)

The fraction of solar energy reflected by a surface, estimated to be approximately $0.3$ (or $30\%\text{}$) for the Earth.

Stefan-Boltzmann constant ($\sigma$)

A physical constant used in temperature equations, valued at $5.67 \times 10^{-8}\,W\,m^{-2}\,K^{-4}$.

High latitude solar angle

Sunlight coming at a higher, more 'upright' angle near the equator, resulting in $95\%\text{}$ absorption and $5\%\text{}$ reflection.

Low latitude solar angle

Sunlight coming at a lower, more 'flat' angle near the poles, resulting in $67\%\text{}$ absorption and $33\%\text{}$ reflection.

Specific Heat Capacity

The amount of energy needed to raise the temperature of a substance; liquid water has a very high value of $4200\,J/kg^{\circ}C$.

Specific latent heat

The amount of thermal energy needed to change the physical state of a material without changing its temperature.

Latent heat of fusion

The heat energy exchanged during the phase change between solid (ice) and liquid (water).

Latent heat of vaporisation

The heat energy exchanged during the phase change between liquid water and water vapour (steam).

External forcing

Primary causes of climate variation outside the internal interactions, including changes in plate tectonics, Earth’s orbit, and the Sun’s strength.

Internal interactions

The interacting components of the climate system, including the atmosphere, vegetation, ice, ocean, and land surface.

Positive feedback

A process where the system responds to a disturbance by amplifying it, potentially creating a 'run-away climate' where hot gets hotter or cold gets colder.

Negative feedback

A process where the system responds to a disturbance by dampening it, creating a 'stabilised climate' where hot cools down or cold warms up.

Atmosphere (Response Time)

A fast-responding component of the climate system with a response time ranging from hours to weeks.

Ice sheets (Response Time)

A slow-responding component of the climate system with a response time ranging from $100$ to $10,000$ years.