CC101 Exam Review: Climate Change and the Pacific

Comprehensive practice flashcards covering Units 1-13 for the CC101 final exam, following the teacher's priority rankings and specific Pacific contexts relating to Pacific Island Countries.

How do weather and climate differ according to the Unit 1 lecture notes?

Weather refers to short-term atmospheric conditions at a particular place and time (hours to days), while climate refers to the average weather pattern of a place over a long period, usually several decades.

What are the five major interconnected components of the climate system?

The atmosphere, hydrosphere, cryosphere, lithosphere (or geosphere), and biosphere.

Explain Earth’s energy balance in terms of radiation types and percentages.

Earth’s climate depends on the balance between incoming solar shortwave radiation and outgoing infrared longwave radiation; approximately $30\%$ of incoming solar energy is reflected, while $70\%$ is absorbed by land and ocean surfaces.

What is the natural greenhouse effect and why is it essential for life?

It is the process by which greenhouse gases (e.g., $H_{2}O$, $CO_2$, $CH_4$, $N_{2}O$, and $O_3$) absorb and re-emit outgoing infrared radiation, keeping Earth about $33^{\circ}C$ warmer than it would be without an atmosphere (average temperature of about $14^{\circ}C$).

Explain the process chain of the ice-albedo feedback.

Warming $\rightarrow$ snow/ice melts $\rightarrow$ darker land or ocean surfaces are exposed $\rightarrow$ lower albedo $\rightarrow$ more solar energy absorbed $\rightarrow$ further warming. This is a positive feedback mechanism.

Describe atmospheric conditions in the Pacific during El Niño.

Trade winds weaken, warm surface water shifts toward the central and eastern Pacific, convection and rainfall shift eastward, and countries like Fiji and PNG often become drier (drought) while Kiribati can become wetter.

What is the Madden-Julian Oscillation (MJO)?

An eastward-moving tropical disturbance of clouds, rainfall, winds, and pressure that travels through the tropics and returns to its starting point in about $30$ to $60$ days.

According to the IPCC AR6, how much did the global surface temperature increase in 2011–2020 compared to 1850–1900?

It was about $1.09^{\circ}C$ higher.

What was the atmospheric concentration of $CO_2$ by February 2025 and why is it significant?

It reached about $426\,ppm$. This is significant because it is the highest level in at least $3$ million years and far higher than any point in the last $800,000$ years.

Define 'Global Warming Potential' (GWP).

A measure that compares how much heat a gas traps over a set time period relative to $CO_2$. For example, $CO_2$ has a GWP of $1$, while methane ($CH_4$) has a GWP of about $28$ over $100$ years.

What are the two main processes contributing to global mean sea-level rise?

1. Thermal expansion of warming seawater and 2. Melting land ice (glaciers and ice sheets).

How much has the mean land temperature in the Pacific Islands increased since 1951?

It has increased by $1.1^{\circ}C$.

Define climate vulnerability using its three main components.

Vulnerability = exposure (physical location) + sensitivity (degree systems are affected) + limited adaptive capacity (ability to respond and recover).

Why is sea-level rise an 'existential' issue for Kiribati and Tuvalu?

These low-lying atolls have average elevations of only $1$ to $3$ meters (Kiribati) and $1$ to $2$ meters (Tuvalu) above sea level, making them vulnerable to chronic flooding, saltwater intrusion, and loss of land.

Distinguish between dynamical and statistical downscaling in climate modelling.

Dynamical downscaling uses a regional climate model nested inside a GCM to simulate detailed processes, while statistical downscaling uses empirical relationships between large-scale variables and local observations.

Matching Scenarios: Define SSP1-2.6 and SSP5-8.5.

SSP1-2.6 is a low-emissions pathway with strong mitigation and sustainable development. SSP5-8.5 is a very high-emissions pathway with continued high fossil fuel use and radiative forcing of $8.5\,W/m^2$ by 2100.

What is the ecological impact of ocean acidification on coral reefs?

Increased $CO_2$ absorption lowers seawater pH and reduces carbonate ion availability, which slows coral calcification, weakens skeletons, and increases reef erosion.

Define 'Blue Carbon' and identify three specific ecosystems included in this category.

Blue carbon is carbon captured and stored in coastal and marine ecosystems; the three main ecosystems are mangroves, seagrass meadows, and saltmarshes.

What are the four dimensions of food security as defined in Unit 7?

Availability (production/supply), Access (affordability/ability to obtain), Utilisation (nutrition/safety), and Stability (reliability over time).

What is the difference between 'adaptation' and 'mitigation'?

Adaptation addresses the impacts of climate change (adjusting systems to reduce harm), while mitigation addresses the root cause (reducing emissions or increasing carbon sinks).

Explain 'Ecosystem-based Adaptation' (EbA) with a Pacific example.

EbA uses biodiversity and ecosystem services to help people adapt; for example, restoring mangroves in Fiji to reduce storm surge and erosion while supporting fisheries.

What is 'maladaptation'?

An action that increases climate vulnerability, shifts risk elsewhere, or creates long-term harm, such as a seawall that protects one village but worsens erosion downstream.

What was the main purpose of the UNFCCC adopted in 1992?

To stabilize greenhouse gas concentrations at a level that prevents dangerous human interference with the climate system.

Describe the Talanoa Dialogue introduced at COP23.

A Pacific-inspired approach presided over by Fiji based on inclusive, transparent, and respectful storytelling to build trust and increase global climate ambition.

What is 'Common but Differentiated Responsibilities' (CBDR)?

The principle that all countries share responsibility for climate action, but developed countries have greater obligations due to historical emissions and stronger financial/technical capacity.

What is the 'Blue Pacific' narrative?

A narrative launched by PIF leaders in 2017 that reframes the region as large oceanic guardians managing $20\%$ of the world’s ocean, rather than small isolated islands.

Explain the role of 'Free, Prior and Informed Consent' (FPIC) in using Indigenous Knowledge.

FPIC requires that communities receive full information, participate voluntarily, retain the right to refuse, and maintain control over their knowledge before it is recorded or shared.

Define 'Systems Thinking' in the context of Unit 13.

Understanding climate change as a set of interconnected processes (atmosphere, ocean, land, etc.) where a change in one part often triggers responses in others.

What is the formula for climate risk assessment mentioned in Unit 13?

Hazard + exposure + vulnerability - capacity = level of climate risk.

Name the specific Pacific village famous for its planned relocation to escape sea-level rise.

Vunidogoloa in Fiji.

What are the potential effects of climate change on the hydrosphere?\n\n

Climate change can lead to altered precipitation patterns, increased ocean temperatures, higher sea levels, and ocean acidification, affecting aquatic ecosystems and water supplies.\n\n

How does the cryosphere influence global climate?\n\n

The cryosphere reflects sunlight due to its high albedo, regulates sea levels through ice melting, and contributes to ocean circulation patterns that impact weather systems worldwide.\n\n

What role does the lithosphere play in the climate system?\n\n

The lithosphere, or geosphere, interacts with the atmosphere and hydrosphere, affecting carbon storage, vegetation growth, and soil composition, which in turn influence local climates.\n\n

How does the biosphere respond to climatic changes?\n\n

The biosphere adapts to climate changes through shifts in species distribution, phenological changes, altered vegetation cover, and impacts on biodiversity and ecosystem services.\n\n

What is the significance of carbon sinks in regulating climate?\n\n

Carbon sinks, such as forests, oceans, and wetlands, absorb CO$_2$ from the atmosphere, helping mitigate climate change by reducing the concentration of greenhouse gases.\n\n

How do ocean currents affect global climate?\n\n

Ocean currents redistribute heat around the planet, influencing regional climates, weather patterns, and the distribution of nutrients in marine ecosystems.\n\n

What indicators are used to measure climate change?\n\n

Indicators include global temperature rise, shrinking ice sheets, declining snow cover, sea level rise, and increasing ocean acidification, all revealing trends in the climate system.\n\n

What are the impacts of thawing permafrost?\n\n

Thawing permafrost releases greenhouse gases like methane, contributing to further climate warming, disrupting ecosystems, and impacting infrastructure in affected areas.\n\n

What is the difference between shortwave and longwave radiation?\n\n

Shortwave radiation refers to the solar energy that reaches Earth, while longwave radiation is the energy emitted by Earth as infrared radiation, crucial for understanding energy balance.\n\n

What is El Niño?

El Niño is a climate pattern characterized by warmer ocean temperatures in the central and eastern Pacific, which can disrupt normal weather patterns globally.

What is La Niña?

La Niña is the counterpart to El Niño, involving cooler ocean temperatures in the central and eastern Pacific, often causing opposite weather effects.

How does positive feedback work in climate systems?

Positive feedback amplifies changes; for example, melting ice reduces albedo, leading to more heat absorption and further warming.

What is albedo?

Albedo is the measure of reflectivity of the Earth's surface; surfaces with high albedo (like ice) reflect more sunlight, while dark surfaces absorb more.

Define radiative forcing.

Radiative forcing refers to the change in energy balance in the Earth's atmosphere due to factors like greenhouse gases, which influences global temperatures.

How has the global mean surface temperature (GMST) changed since the industrial revolution?

Global mean surface temperature increased by about $1.09^{\text{°C}}$ between 2011 and 2020 compared to pre-industrial levels.

What is downscaling in climate modelling?

Downscaling refers to techniques used to derive finer-scale climate data from larger-scale models, enhancing local predictions.

What are Global Climate Models (GCMs)?

GCMs are computational models used to simulate Earth's climate system and predict climate changes based on various scenarios.

Explain the SSP5 socioeconomic pathway.

SSP5 is a high-emission pathway in climate modelling that assumes continued fossil fuel use and prioritization of economic growth.

What is ocean acidification?

Ocean acidification occurs when excess $CO_2$ is absorbed by oceans, leading to lower pH levels and affecting marine life.

Define GLMSL (Global Mean Sea Level) rise.

GLMSL rise refers to the average increase in sea levels globally, primarily caused by melting ice and thermal expansion due to warming.

What is the Madden-Julian Oscillation (MJO)?

MJO is an eastward-moving tropical disturbance that influences rainfall and wind patterns in the tropics over a period of 30 to 60 days.

What is the ENSO cycle?

The ENSO (El Niño Southern Oscillation) cycle is a periodic fluctuation in sea surface temperatures and atmospheric conditions in the Pacific.

Describe the Walker circulation.

Walker circulation is a large-scale atmospheric circulation pattern in the tropics that influences trade winds and ocean currents.

What is the significance of the SPCZ (South Pacific Convergence Zone)?

SPCZ is an area of convergence where trade winds meet, leading to increased rainfall and affecting storm patterns in the South Pacific.

What is the Western Pacific Warm Pool?

The Western Pacific Warm Pool is a region of warm water in the western Pacific, crucial for tropical cyclone formation and regional climate.

What is the Intertropical Convergence Zone (ITCZ)?

ITCZ is a belt of low pressure around the equator where trade winds converge, causing frequent thunderstorms and heavy rainfall.

What does IPCC AR6 report regarding climate change?

The IPCC AR6 report warns of 'unequivocal' climate change and stresses the urgent need for action to mitigate its impacts.

What are paleoclimate proxies?

Paleoclimate proxies are natural recorders of climate variability, such as tree rings and ice cores that provide insights into past climates.

What are Earth System Models (ESMs)?

ESMs are advanced climate models that simulate interactions between the atmosphere, oceans, land, and biosphere.

What are Regional Climate Models (RCMs)?

RCMs are models that provide high-resolution climate projections for specific regions, often used to inform local climate policy.

Define SSPs (Shared Socioeconomic Pathways).

SSPs are scenarios that describe possible futures influenced by socioeconomic factors affecting global change and climate impacts.

What is the RCP (Representative Concentration Pathway) framework?

RCPs are scenarios that outline different greenhouse gas concentration trajectories used in climate modelling.

What is Blue Carbon degradation?

Blue Carbon degradation refers to the loss of carbon capture and storage capability in coastal and marine ecosystems, impacting climate mitigation.

Explain Ecosystem-based Adaptation (EbA).

EbA utilizes biodiversity and ecosystem services to support adaptive responses to climate impacts, improving resilience.

What is Community-Based Adaptation (CBA)?

CBA focuses on local community involvement in adapting to climate change, prioritizing local knowledge and needs.

What are carbon sinks?

Carbon sinks are natural systems, like forests and oceans, that absorb more carbon dioxide than they release, playing a crucial role in reducing atmospheric CO2 levels.

Define climate variability.

Climate variability refers to the natural fluctuations in climate patterns over time, including seasonal and interannual changes.

What role does the cryosphere play in climate systems?

The cryosphere influences Earth's climate by regulating sea levels and reflecting solar radiation, with significant feedback effects.

What percentage of Earth's surface is covered in water?

Approximately 71% of the Earth's surface is covered by water, playing a critical role in climate regulation and ecosystems.

What is the greenhouse effect?

The greenhouse effect is the warming of Earth's surface due to the trapping of heat by greenhouse gases in the atmosphere, which is essential for maintaining life but is intensified by human activities.

What is carbon footprint?

A carbon footprint is the total amount of greenhouse gases emitted directly or indirectly by an individual, organization, event, or product measured in units of carbon dioxide equivalent (CO2e).

Explain the significance of tipping points in climate change.

Tipping points are critical thresholds in the climate system beyond which a small change can lead to drastic environmental alterations, such as the collapse of ice sheets or the dieback of forests.

What are feedback loops in climate science?

Feedback loops in climate science are processes that can either amplify (positive feedback) or diminish (negative feedback) the effects of climate change, often leading to accelerated warming.

What is the role of methane in climate change?

Methane is a potent greenhouse gas, with a global warming potential significantly higher than CO2 over a short time period; its release from permafrost and agriculture is a major concern in climate change.

What is the significance of the ocean conveyor belt?

The ocean conveyor belt is a system of deep ocean currents that significantly influences global climate by redistributing heat and nutrients around the planet.

How does deforestation impact climate change?

Deforestation increases atmospheric CO2 levels by reducing the number of trees that can absorb carbon, disrupting ecosystems, and altering local and global climate patterns.

What are the implications of sea-level rise?

Sea-level rise poses threats to coastal communities through increased flooding, erosion, and loss of habitat, exacerbating the impacts of climate change on vulnerable populations.

How does climate change affect biodiversity?

Climate change alters habitats and ecosystems, leading to shifts in species distribution, increased extinction rates, and challenges to the survival of various organisms.

What is the role of policy in addressing climate change?

Policy plays a critical role in addressing climate change through regulations that promote carbon reduction, conservation efforts, and incentives for renewable energy adoption.