Climate Change Lecture – Key Vocabulary

A comprehensive set of vocabulary flashcards covering major terms, processes, and concepts related to climate change as presented in the lecture notes.

Solar Variability

Natural fluctuations in the Sun’s energy output that follow an 11-year solar cycle of maximum and minimum activity.

Solar Cycle

An 11-year pattern of changing sunspot numbers and magnetic field strength that slightly alters solar radiation reaching Earth.

Sunspot

Dark, cooler region on the Sun’s surface linked to increased solar activity and minor changes in solar radiation.

IPCC (Intergovernmental Panel on Climate Change)

UN body that assesses climate science, impacts, and mitigation options and issues periodic global reports.

Volcanic Eruptions

Natural events that emit CO₂, sulphur dioxide, and other gases, temporarily affecting atmospheric composition and climate.

Greenhouse Gas (GHG)

Atmospheric gas that absorbs and re-emits infrared radiation, warming Earth’s surface and lower atmosphere.

Carbon Dioxide (CO₂)

Primary anthropogenic greenhouse gas whose concentration rose from ~280 ppm (pre-1800) to ~418 ppm (2021).

Methane (CH₄)

Potent greenhouse gas released by livestock, wetlands, and fossil fuels; has a higher warming potential than CO₂ over 100 years.

Nitrous Oxide (N₂O)

Greenhouse gas emitted mainly from agriculture and industry; traps heat and contributes to stratospheric ozone depletion.

Water Vapour

Most abundant greenhouse gas; its concentration varies with temperature and amplifies warming through a positive feedback loop.

Chlorofluorocarbons (CFCs)

Synthetic gases once used in refrigeration and aerosols; powerful greenhouse gases that also destroy stratospheric ozone.

Halons

Bromine-containing synthetic gases used in fire suppression; strong greenhouse and ozone-depleting substances.

Greenhouse Effect

Natural process where greenhouse gases trap outgoing infrared radiation, keeping Earth’s average surface temperature around 15 °C.

Enhanced Greenhouse Effect

Additional warming caused by human-induced increases in greenhouse gas concentrations.

Albedo

Fraction of incoming solar radiation that a surface reflects; ranges from 0 (absorbs all) to 1 (reflects all).

Ice-Albedo Feedback

Positive feedback in which melting ice lowers surface albedo, leading to more heat absorption and further melting.

Ocean Circulation

Movement of seawater via surface currents and deep thermohaline flows that redistribute heat and regulate climate.

Thermohaline Circulation

Global deep-water ‘conveyor belt’ driven by temperature and salinity differences, transporting heat, nutrients, and CO₂.

Carbon Sequestration

Process of capturing and storing atmospheric carbon in oceans, vegetation, soils, or geological formations.

Ocean Sequestration

Dissolution of CO₂ into seawater followed by biological uptake and sedimentation, making oceans the largest carbon sink.

Land-Based Sequestration

Storage of carbon in forests, soils, and vegetation; disrupted by deforestation, fires, and land-use change.

Anthropogenic Sequestration

Human-engineered storage of CO₂, such as injecting the gas into deep geological formations or mineralizing it in rocks.

Global Warming

Long-term increase in Earth’s average surface temperature primarily due to human-generated greenhouse gases.

Climate Feedback Loop

Process that amplifies (positive) or dampens (negative) initial climate changes, complicating predictions.

Global Warming Potential (GWP)

Index comparing the heat-trapping ability of a greenhouse gas to CO₂ over a specific time horizon (usually 100 years).

Ozone Layer

Stratospheric region rich in O₃ that absorbs most harmful ultraviolet (UV-B) radiation from the Sun.

Montreal Protocol (1987)

International treaty that phased out ozone-depleting substances such as CFCs and halons.

Troposphere

Lowest atmospheric layer where weather occurs and most greenhouse gases and moisture are found.

Stratosphere

Atmospheric layer above the troposphere containing the protective ozone layer.

Mesosphere

Middle atmospheric layer where temperatures decline with altitude; meteors often burn here.

Thermosphere

Outer atmospheric layer characterized by very high temperatures and low air density.

Paleobotany

Study of fossilized plants and pollen to reconstruct past climates and ecosystems.

Ice Core Sampling

Extraction of deep ice cylinders that trap ancient air bubbles, revealing historic atmospheric composition and temperature.

Tree Ring Analysis (Dendrochronology)

Examination of annual growth rings to infer past climate conditions such as precipitation and temperature.

Coriolis Effect

Apparent deflection of moving air and water due to Earth’s rotation, influencing wind and ocean currents.

Carbon Sink

Natural or artificial reservoir that absorbs more carbon than it releases, such as forests or oceans.

Fossil Fuels

Coal, oil, and natural gas formed from ancient organic matter; their combustion emits large amounts of CO₂.

Deforestation

Removal of forests, reducing carbon storage and altering albedo, transpiration, and local climate.

Ocean Acidification

Decrease in seawater pH caused by CO₂ absorption, harming corals and marine life.

Global Winds

Large-scale wind patterns (e.g., trade winds, westerlies) that drive surface ocean currents.

Climate Projection

Model-based estimate of future climate conditions under specified greenhouse gas emission scenarios.

UNFCCC (United Nations Framework Convention on Climate Change)

1992 international treaty establishing a framework for climate change mitigation and adaptation efforts.

Kyoto Protocol

1997 agreement under the UNFCCC that set binding emission reduction targets for developed nations.

Emissions Trading

Market-based system allowing entities to buy and sell permits for greenhouse gas emissions.

Biodiversity

Variety of life in all forms and levels, from genes to ecosystems; threatened by climate change.

Phenology

Timing of seasonal biological events (e.g., flowering, migration) that can be disrupted by warming climate.

Invasive Species

Non-native organisms that spread rapidly, outcompete natives, and often expand under changing climates.

Sea Level Rise

Increase in average ocean height due to melting ice and thermal expansion of warming water.

Mitigation

Actions aimed at reducing or preventing greenhouse gas emissions to slow climate change.

Adaptation

Adjustments in systems or practices to minimize harm or exploit beneficial opportunities from climate impacts.

Stakeholder Decision-Making

Process where diverse groups (communities, governments, industry, First Nations Peoples) shape climate responses based on values and evidence.

Stevenson Screen

White, ventilated enclosure that shields thermometers from direct sunlight and precipitation for accurate air-temperature readings.

Climate Modelling

Use of mathematical simulations to replicate and predict Earth’s climate systems and future trends.

First Nations Knowledge

Indigenous ecological understanding and low-carbon practices that inform sustainable resource management and adaptation.