Exam revision (semester 1 content) Flashcards
Define environment
Key concepts of land cover change
Environment means the living and non-living elements of the Earth’s surface and atmosphere. It includes human changes to the Earth’s surface.
E.g., croplands, planted forests, buildings, and roads.
Define natural biome
Key concepts of land cover change
A biome is a community of life forms adapted to a large natural area.
Natural biomes are those which have not had sustained direct human interactions.
E.g., aquatic, desert, forest, grassland, and tundra.
Define anthropogenic biome
Key concepts of land cover change
A biome is a community of life forms adapted to a large natural area.
Anthropogenic biomes are biomes that are the result of sustained direct human interactions with ecosystems.
E.g., urban, rural or villages, croplands, and rangelands.
Define land cover change
Key concepts of land cover change
Land cover change refers to the changes that have taken place in natural environments due to a variety of natural and/or human induced causes.
Define ecosystem structure
Key concepts of land cover change
An ecosystem is a community of plants and animals in a non-living environment.
The ecosystem has a structure made up of the biotic and abiotic elements, with a hierarchy of organisms, that is, trophic levels.
Includes producers, consumers, and detritus.
Define ecosystem dynamics
Key concepts of land cover change
An ecosystem is a community of plants and animals in a non-living environment.
The ecosystem is dynamic, that is, there are relationships between biotic ad abiotic elements, which includes the flow of energy between the elements.
E.g., food chains and food webs. There is also an exchange of matter, i.e., the nutrient cycle.
Define biodiversity loss
Key concepts of land cover change
The extinction of species (plant or animal) worldwide, and also the local reduction or loss of species in a certain habitat.
Define climate change
Key concepts of land cover change
A long-term change in the statistical distribution of weather patterns over pediods of time that range from decades to millions of years.
E.g., rainfall in the southwest of WA has reduced by approximately 20% over the last 50 years.
Define sustainability
Key concepts of land cover change
Sustainability is meeting the needs of current and future generations through simultaneous environmental, social, and economic adaptation and improvement.
Describe deforestation
Processes of land cover change
Deforestation is the removal or clearing of forests generally for other uses, such as agriculture and urban development.
Between 1700 and 2018, one-third of the world’s forest were lost, half of which has occurred in the last century.
Borneo
Example for deforesation
Processes of land cover change
Borneo, an island in Southeast Asia, once had dense rainforests and mangroves, but much has been converted to industrial oil palm and timber plantations.
Since 2000, 40% of deforestation in Borneo has been driven by the expansion of oil palm plantations.
Describe the expansion of agriculture
Processes of land cover change
The expansion of agriculture refers to the increasing amount of land available for agriculture.
Currently, over a third of the world’s terrestrial land is dedicated to crop and livestock production.
Describe the intensification of agriculture
Processes of land cover change
The intensification of agriculture refers to an increase in the output from existing agricultural areas. By adjusting factors such as labour, fertilisers, seeds, or technology.
E.g., there has been a 300% increase in food crop production since 1970.
Describe the growth of urban settlement
Processes of land cover change
The land required to support urban areas undergos a transformation including clearing native vegetation and building infrastructure.
E.g., urban areas have more than doubled in size since 1992.
Describe mining
Processes of land cover change
Mining affects biodiversity and land cover change, with significant amounts of land being cleared, use and release of chemicals, dust, and aerosols.
E.g., sediment movement from Madre de Dios in Peru has degraded many ecosystems along connecting rivers in Brazil.
Remote sensing
The science of obtaining information about objects or areas from a distance, typically from aircraft or satellites.
Copernicus Sentinel-2, 2019 Queensland floods
Remote sensing example
A remote sensing operation that provides many bands of data, including infrared and spatial resolution from two satellites.
E.g., shows sediment moving into Great Barrier Reef lagoon after 2019 Queensland floods.
Outline the impacts of world population growth
Population, affluence, and advances in technology on land cover change
The rate and extent of land cover change has increased as there is a higher demand for resources such as food (agricultural land use) and urban settlements must expand.
Outline the impacts of affluence
Population, affluence, and advances in technology on land cover change
More affluence, more demand for resources, including eat. Diets of more affluent countries tend to have higher rates of dairy and meat consumption.
Half of habitable land is used for food production.
Outline the impacts of advances in technology
Population, affluence, and advances in technology on land cover change
For example, changes in time it takes to cut a tree; from handsaws and chainsaws to large, efficient machines which have sped up the process of deforestation.
Related to intensification of agriculture.
Mosaic burning
Impact of Aboriginal and Torres Strait Islander peoples
Mosaic burning is the use of regular, relatively controlled, low intensity burns in a patchwork system. It was used to clear native vegetation, reduce bushfires, and assist in seed germination.
Impact of mosaic burning over time
Impact of Aboriginal and Torres Strait Islander peoples
Areas were gradually changed from dense forest or bush to more medium scrublands. It ensured forests were not destroyed and assisted in the growth of new vegetation (such as the acacia).
Loss of habitat
Impacts of land cover change
Loss of habitat can include the thinning, fragmentation, or destruction of a habitat, often due to processes of land cover change such as deforestation.
Loss of biodiversity
Impacts of land cover change
Is linked with loss of habitat. Loss of habitat results in loss of biodiversity, endangerment and extinction of species, and ecological imbalance.
Carnaby’s black cockatoo
Loss of habitat and biodiversity example
Impacts of land cover change
The population has more than halved in the last 45 years, locally extinct in many parts of Wheatbelt. Due to large-scale clearing for agriculture and urban development.
Ocean acidification
The degradation of aquatic and marine environments
Impacts of land cover change
Ocean acidification can occur because of the dramatic rise in carbon dioxide levels in the atmosphere, created from processes of land cover change, such as agriculture.
As oceans absorb the carbon dioxide, the pH levels decrease, and the water becomes more acidic.
Ocean acidification, Industrial Revolution, marine life
The degradation of aquatic and marine environments example
Impacts of land cover change
Since the Industrial Revolution, 30% increase in ocean acidity. This affects marine life, corals and clams, have greater difficulty creating and building their calcium based shells.
Where does rainfall primarily occur
Spatial distribution of rainfall and temperature patterns
Rainfall primarily occurs within regions of rising moist air and low pressure. The highest concentration of rainfall occurs at low latitudes near the equator.
The mid-latitude temperate regions, such as New Zealand, exhibit moderate to high levels of rainfall.
Rainfall in coastal areas and windward slopes
Spatial distribution of rainfall and temperature patterns
Coastal areas tend to experience higher rainfall than inland areas. Regions on windward slopes of mountains also experience high levels of rainfall.
Kalamunda, windward side of the Darling Escarpment receives twice as much rain per year compared to York, leeward side.
Where is rainfall lowest
Spatial distribution of rainfall and temperature patterns
Rainfall is lower in subtropical regions, such as the Sahara Desert, and polar regions, such as Antarctica, which is the driest continent in the world.
Warmer areas
Spatial distribution of rainfall and temperature patterns
Areas closer to the equator are warmer than areas closer to the poles (25°C average). Warmest in the subtropical climate zone, and more comfortable in the temperate mid-latitude zones.
Areas of low albedo
Spatial distribution of rainfall and temperature patterns
Areas of low albedo, where more insolation is absorbed, tend to have higher temperatures. Forests such as the Amazon rainforest which has an annual average temperature of 25°C and can reach 40°C.
Areas of high albedo
Spatial distribution of rainfall and temperature patterns
Areas of high albedo, where more insolation is reflected, tend to have lower temperatures. For example, alpine (snow/ice-covered) areas such as Greenland.
Heat budget
The Earth’s natural systems
All insolation received by Earth is eventually returned to space, maintaining a balance known as the heat budget.
Percentages reflected/absorbed in the heat budget
The Earth’s natural systems
30% of incoming solar energy is immediately reflected. 20% is absorbed by atmosphere, while 50% absorbed by land and oceans. This energy is then re-radiated as terrestrial long-wave radiation.
When does the greenhouse effect occur
The Earth’s natural systems
When greenhouse gases in the atmosphere, such as carbon dioxide and methane, absorb some of this radiation and re-radiate it in all directions. Slows the passage of heat and moderates the temperature.
Hydrological cycle
The Earth’s natural systems
The continuous movement of water as a liquid, gas, and solid throughout the land, oceans, and atmosphere.
Evaporation, condensation, and precipitation
The Earth’s natural systems
As water vapor rises and cools, it condenses into tiny liquid droplets, forming clouds and leading to precipitation as rain, snow, or hail.
Infiltration, run-off, and transpiration
The Earth’s natural systems
Rain can infiltrate the ground, seeping into rivers or lakes, or run off the land’s surface to continue the cycle. Plants absorb water through roots and release as vapour through leaves, transpiration.
Carbon cycle
The Earth’s natural systems
The continuous movement of carbon compounds between land, oceans, the atmosphere, and living organisms. Key processes either remove or release carbon into the atmosphere.
Natural processes that remove carbon from the atmosphere
The Earth’s natural systems
Precipitation, photosynthesis, erosion, and sedimentation remove carbon dioxide from the atmosphere.
Carbon through the oceans
The Earth’s natural systems
Carbon is absorbed at the surface and cold sinking water transfers it to deep waters, where it can be stored with shells and sediments. When warm water rises, carbon is released back into the atmosphere.
Carbon through plants and animals
The Earth’s natural systems
Plants absorb carbon dioxide through photosynthesis and release it during respiration, while animals also exhale it. The decay or burning of plant materials further releases carbon dioxide.
Atmospheric circulation
The Earth’s natural systems
The large-scale movement of air, which helps distribute thermal energy across Earth. Three main cells, the Hadley, Ferrel, and Polar cells, circle the planet both north and south of the equator.
Hadley cells
The Earth’s natural systems
Hadley cells, driven by surface temperatures, transfer heat from equator to poles, balance global temperatures.
Polar cells
The Earth’s natural systems
Polar cells, moving warm air toward poles, where it cools and descends, creating cold surface conditions.
The Earth’s natural systems
Ferrel cells, located between the Hadley and Polar cells, circulate air between warm subtropical regions and cool polar areas.
What do the atmospheric cells create
The Earth’s natural systems
Alternating belts of high and low pressure across Earth’s surface, influencing weather patterns. Low-pressure areas: cloudy, windy conditions. High-pressure areas: stable, often clear skies.
Solar variations
Sunspot or Solar Cycle. Sunspots are magnetic storms that occur on the Sun’s surface, increase expulsion of radiation, if directed to Earth, can affect insolation reaching the planet.
Sunspot activity occurs in an 11-year cycle, with the number of sunspots greatest at around 5.5 years before declining again.
Maunder Minimum
Late 17th century, sunspot activity decreased dramatically and almost no sunspots were observed. A cooling effect, and winters in Europe were longer and colder by about 1°C than they are today.
Volcanic eruptions
By releasing gases like sulphur dioxide and carbon dioxide, along with dust and ash, into the atmosphere.
How do volcanic eruptions cause lower temperatures
Initially, dust and ash can cause short-term cooling by reflecting insolation. Once sulphur dioxide reaches the stratosphere it forms sulfuric acid droplets, which reflect sunlight.
Mt Tambora example
Mt Tambora, in Indonesia, which erupted in 1815. The following year known as the Year Without a Summer experienced a 0.4-0.7°C decrease in average global temperature.
Power generation
Power generation is the largest contributor to greenhouse gas emissions. Over 40% of energy-related carbon dioxide emissions are a result of the combustion of fossil fuels for electricity generation.
Power generation - transportation
Transportation and the associated burning of fossil fuels to power it accounts for approximately 15% of global greenhouse gas emissions.
How have private vehicle ownership impacted transport emissions
The increase in private vehicle ownership, the expansion of freeways, and urban sprawl have resulted in Australia’s transport emissions increasing by nearly 60% since 1990.
Government policy in Australia is…
Government policy accounting for differences
strict in terms of rehabilitation of deforested areas. E.g., Argyle mine site, closed in 2020, mandated rehabilitation for 5 years before being returned to traditional custodians.
Land Use Agreement 2005
In Brazil, the government identified…
Government policy accounting for differences
the Amazon rainforest as an area with significant potential for economic growth, building trans-Amazonian highway, giving out free plots of land, paying citizens to deforest.
However, there has been a shift in government policies…
Government policy accounting for differences
and between 2004 and 2014, there was an 80% decrease in the rate of deforestation of the Amazon, with the implementation of the Forest Code (only 20% of farmland can be cleared).
An ice core is a…
Climate change through geological history
cylindrical sample taken from ice sheets such as Greenland and Antarctica, capturing preserved records of past climate. Trapped air bubbles in the ice contain samples of gases.
For example, the Vostok ice core…
Climate change through geological history
reveals data from about 800,000 years ago. Ice cores show greenhouse gas cycles, with lower levels (180ppm) in glacial periods, and higher levels (300ppm) in interglacial periods.
Sea level rise refers to…
Climate change in recent human history
an increase in sea level, as measured by remote sensing and tide gauges. The result of expansion of sea water and increased amount of water due to melting ice sheets and glaciers.
Global sea level has risen by over…
Climate change in recent human history
20cm since 1880, and this rate has been accelerating in previous years, corresponding with increasing global temperature due to climate change.
Rising temperatures from climate change…
Impacts of climate change on ice sheets and glaciers
have led to more ice melting and less accumulation, with over half of the world’s glacier ice lost since the 19th century. By 2100, another 50% may disappear.
Ice loss disrupts…
Impacts of climate change on ice sheets and glaciers
polar ecosystems by altering animal relationships, food availability, and exposure to new predators. E.g., Arctic ringed seals lose habitat and food sources, increased predation from killer whales moving in to previously inaccessible areas.
Also polar bear and arctic fox, from red fox moving in.
However, some species…
Impacts of climate change on ice sheets and glaciers
such as Adelie penguins, are benefiting from reduced sea ice. Scientists discovered they walk up to 5km more in less time on foraging trips, led to improved chick growth rates.
Climate change poses major risks to…
low-lying urban areas vulnerable to sea level rise caused by thermal expansion and ice melt. Over 360 million people live less than 10m asl in coastal cities, Dhaka, Manila, islands in Oceania at risk.
Dhaka’s coastal slums…
home to 30% of its population, widespread displacement, casualties, and property loss from flooding. Carteret Islands, evacuation in 2003 due to land loss, rapid submersion.
By 2050, rising seas could…
displace 200 million globally, potentially leading to the disappearance of islands such as Kiribati and Maldives within 30 to 60 years. Niger and Mali may benefit from changing rainfall patterns.
