HASS | Geography (Test 1 and Exam 1)

Environmental Change and Management

Climate change

Any long-term significant change in the average weather that a given region experiences - usually over 30 years. This can be caused by natural or human activities.

Anthropogenic climate change

Significant changes in the average weather that a given region experiences, caused by the actions of people.

Global warming

An increase in the average temperature of the Earth's atmosphere and surface, especially a sustained increase that causes climate change

Greenhouse effect

The natural process that warms the lower level of the atmosphere through the trapping of re-radiated terrestrial radiation by greenhouse gases

Enhanced greenhouse effect

The extra warming of the atmosphere caused when humans add greenhouse gases to the atmosphere, which trap more energy

Sustainability

Meeting the needs of current and future generations through simultaneous social, environmental and economic adaptation and improvement

Environmental challenge: climate change

Facts: Earth's temperature is rising as a result of human activity

Causes: Increased greenhouse gases entering Earth's atmosphere (enhanced greenhouse effect)

Effects: global warming by 1.2°C since 1800, changed rainfall, weather and temperature patterns, melting icebergs that lead to sea level rises

Environmental challenge: land degradation

Facts: land is eroding and being destroyed

Causes: Human activites such as removal of trees, overuse of farming fields

Effects: can cause loss of soil fertility, soil erosion and increased salinity in soil, loose soil and landslides

Environmental challenge: loss of biodiversity

Facts: biodiversity is the number of species in an ecosystem. currently decreasing rapidly: 17K-1mil species lost each year

Causes: deforestation, pollution, water loss

Effects: can cause a decrease in food, fibre, pollinators and protection against natural disasters

Human-centred world view

• humans are the dominant and most important species

• humans should manage the earth for their own benefit

• should always support our ever-growing populations using every resource we can from nature

Stewardship world view

• humans should live in harmony with nature, be stewards of it-

example of how aboriginal Australians think

Earth-centred world view

• humans are just one species in a world of many

• humans have the responsibility to use resources in a sustainable way

• every species has the right to live as humans do

Aboriginal and Torres Strait Islander peoples' approach to their land

• they have a meaningful responsibility to protect their land, water, resources and animals

• they view custodianship as a deep, spiritual connection to their country

How the climate has changed over geological time

Earth's climate has always changed through periods of warmer and cooler global temperatures. These change the amount of ice found on the Earth's surface as well as altering sea levels, vegetation cover, desert formation and other aspects of the Earth's surface.

Glacial

• very cold

• big ice sheets

• 30% ice (globally)

• sea levels drop

• approx. 80k years

Inter-glacial

• warmer than glacials

• ice sheets retreat

• 10% ice (globally)

• sea levels rise

• approx. 20k years

Proxy

A substitute, e.g. studying the glacier and using the length of it to assume something else (temp change)

Greenhouse gases

Gases in the atmosphere surrounding the earth that absorb heat energy. E.g. Carbon Dioxide (C02), Methane (CH4), Nitrous Oxide (N20), and Water vapour (H20)

Greenhouse gas sources - natural and anthropogenic

• CO2: Natural causes (Venting volcanoes, outgassing from oceans), Human causes (Burning fossil fuels for electricity, heat and transport)

• CH4: Natural causes (Decaying organic matter in oceans, micro-organisms in water-bogged soils), Human causes (Agricultural byproducts, lan use and biomass burning)

• N2O: Natural causes (Microbial process in soils and oceans), Human causes (Agricultural byproducts)

The greenhouse effect process

1. solar radiation comes from the sun

2. insolation is absorbed at Earth's surface and converted into heat

3. heat is emitted into the atmosphere. some passes to space, and some is absorbed by GHGs in the atmosphere

4. GHSs absorb & re-emit the heat in all directions. Some do the heat travels back to Earth's surface resulting in warming temperatures (by 33°C)

Enhanced greenhouse effect process

1. solar radiation comes from the sun

2. insolation is absorbed at Earth's surface and converted into heat

3. heat is emitted into the atmosphere. some passes to space, and some is absorbed by GHGs in the atmosphere

4. GHSs absorb & re-emit the heat in all directions. Some do the heat travels back to Earth's surface resulting in warming temperatures (by 33°C)

5. human activities such as power generation, car use, deforestation and agriculture increase the concentration of GHGs in the atmosphere. This causes extra warming.

Describe the spacial pattern of global CO2 emissions and compare to levels of development

CO₂ emissions are unevenly distributed, concentrated in industrialised and urban regions such as North America, Europe, and East Asia. Saudi Arabia produce oil = lots of CO2 emissions. Developed nations emit more per capita, while developing countries have lower per capita but rapidly increasing total emissions as they industrialise.

Locate Kiribati and Australia on a map - including oceans and island names

• Australia is a continent-sized nation in the Southern Hemisphere, bordered by the Indian Ocean to the west and the Pacific Ocean to the east. Kiribati is a dispersed Pacific island nation located roughly halfway between Hawaii and Australia, spanning both the equator and the International Date Line

• Gilbert Islands: Located in the west, closer to Australia. South Tarawa is located there - the capital.

• Phoenix Islands: Located in the centre.

• Line Islands: Located far to the east, spanning the equator.

Climate effects on Kiribati

• rising sea levels

• increased/irregular storms

• temperature rise

Impacts of rising sea levels on Kiribati

• beaches destroyed

• land flooded/eroded

• habitat destroyed

• infrastructure destroyed

Impacts of coastal erosion on Kiribati

Loss of land, displacement of communities, saltwater intrusion into freshwater supplies, damage to infrastructure, decline in fisheries, and loss of cultural heritage.

Coral bleaching

A stress response that occurs when water conditions are not right

Coral bleaching process

The algae, instead of producing food for the coral, produces harmful chemicals as a result of the changed water conditions. the coral expels the algae into the water and it appears white/pale as it does so

Impacts of coral bleaching on Kiribati

Coral bleaching in Kiribati reduces reef biodiversity, undermines fisheries and tourism, weakens coastal protection, and threatens food security and cultural heritage.

Adaptation

Modify to suit the impacts of climate change (impacts), local

Mitigation

Removing the causes, or reducing the severity, of climate change (causes), global

Kiribati planting mangroves - climate change solution

Planting mangroves in Kiribati is an adaptation strategy to climate change. By establishing mangrove forests along the coast, the islands reduce shoreline erosion, buffer storm surges, and protect freshwater supplies. heir complex root systems stabilise the shoreline. Mangroves also provide habitat for fish and other wildlife, support local fisheries, and sequester carbon, but the primary aim is to lessen the impacts of sea‑level rise and extreme weather rather than to cut greenhouse‑gas emissions.

Summary of pros of mangroves in Kiribati as an adaption to climate change

• protects beaches against coastal erosion

• filters nutrient runoff

• not as costly as other possible solutions

• prevents destruction of infrastructure

• can be planted by the community

• protects people

Summary of cons of mangroves in Kiribati as an adaption to climate change

• barnacles have destroyed seedlings

• alters the natural atolls (replaces sandy beaches)

• changes natural environment that locals use recreationally

Sustainability of planting mangroves in Kiribati in economic, social and environmental terms

• Social: increases food security, protects people, makes seafood available. However, changes the natural beach environment that communities use for recreation

• Economical: they enhance fisheries, tourism, prevents destruction of infrastructure, can generate income through sustainable harvesting. However they require investment (time = money - $150k) and ongoing maintenance.

Impacts of sea level rise to coastal areas in Australia

Sea‑level rise threatens Australian coastal areas with increased flooding, accelerated shoreline erosion, saltwater intrusion into freshwater aquifers, and damage to infrastructure and tourism assets, leading to economic losses and potential displacement of communities.

Impacts of coastal erosion to coastal areas in Australia

Coastal erosion in Australia leads to loss of shoreline and property, damages infrastructure such as roads, seawalls and utilities, reduces tourism revenue, threatens marine and terrestrial habitats, increases flood risk, lowers property values, and endangers cultural and historical sites.

Impacts of coral bleaching to coastal areas in Australia

Loss of reef structure and biodiversity, weakened coastal protection, decline in tourism and fishing income, and increased vulnerability to erosion and storm damage.

Australia desalination for water supply - climate change strategy

Desalination is an adaptation strategy used in Australia to secure water supplies under climate change. It converts seawater into potable water by reverse‑osmosis or thermal processes, providing reliable water for cities, agriculture and industry, especially in drought‑prone regions. Benefits include independence from rainfall, the ability to meet peak demand and resilience to extreme heat. Challenges are high energy consumption, cost, brine disposal and environmental impacts. Australian projects such as the Perth Seawater Desalination Plant and the Adelaide Desalination Plant illustrate its role in mitigating water scarcity, making it a key adaptation measure rather than a mitigation strategy.

Sustainability of desalination plants in Australia in economic, social and environmental terms

• Environmental: Climate independent, protects freshwater environments. However, makes ocean saltier, may ruin dune vegetation, bad place to build - on coast, sea levels + erosion

• Economic: Long term water security - 100b water/yr. However, expensive to build ($2-3b), time delay

• Social: Improves water for many places/people, less water restrictions, public space greenery. However, traffic disruption

Conference of parties

Large meetings that have been held between the leaders of many nations with the purpose of agreeing on ways to tackle climate change and setting targets for the reduction of their GHG emissions.

International strategy to adapts/mitigate climate change - Kyoto protocol

• 1997, #3 COF (1st = Berlin)

• 1st set legally binding targets for developing countries to reduce GHG emissions

• Developed nations agreed to cut emissions by average 5.2% below 1990 in next 5 years

• Australia = negotiated deal, increase emissions by up to 8% above 1990 levels by 2012. Economy relied heavily on fossil fuels and agriculture, making deep cuts difficult

International strategy to adapts/mitigate climate change - COP 21 "The Paris Agreement"

• 2015, #21 COF

• Limiting global warming to below 2ºC, aim for 1.5ºC above pre-industrial levels

• All 195 countries agreed to set own Nationally Determined Contributions (NDCs) for reducing emissions

• Review + strengthen targets every five years

• After Copenhagen (#15) "failure" due to no legal obligations, this was seen as a success

COP26 Glasgow - 2021

• Goal = net-zero emissions by 2050

• Commitmment = reduce coal power and fossil fuel industries

• REduce methan emissions by 30% by 2030