Environmental Change and Sustainability - TCE Geography (Tasmania)
“Human activity drives environmental change at multiple scales, and sustainability frameworks help assess whether systems can persist over time.”
Environmental change is any alteration to natural systems, driven by natural processes and increasingly by human activity. Sustainability asks whether we are using environments in ways that can continue without degrading them for future generations, judged across environmental, social and economic dimensions.
What this dot point is asking
Environmental change refers to shifts in the condition of natural systems: the atmosphere, hydrosphere, biosphere and lithosphere. Change has always occurred through natural processes such as volcanic activity, glacial cycles and natural climate variability. What concerns geographers today is the pace and scale of human-induced change. Since the Industrial Revolution, and accelerating after about 1950 in what many scientists call the Great Acceleration, human pressures on the environment have grown sharply alongside population, consumption and global flows.
The main drivers of human-induced change are population growth, rising per-capita consumption, technology and energy use, and land-use change. Burning fossil fuels increases atmospheric carbon dioxide, intensifying the enhanced greenhouse effect and driving climate change. Deforestation, agriculture and urban expansion alter habitats and the carbon cycle. Pollution affects air, water and soil. These pressures interact: climate change worsens biodiversity loss, which in turn weakens ecosystem services such as pollination, clean water and carbon storage.
Key impacts include warming temperatures, sea-level rise, ocean acidification and warming, more frequent and intense extreme events, and biodiversity decline. Tasmania provides clear local evidence. The seas off eastern Tasmania are a global ocean-warming hotspot, warming faster than the global average. This has driven the southward spread of the long-spined sea urchin from New South Wales waters, which overgrazes kelp and creates barren rocky reefs, damaging giant kelp forests and the abalone and rock-lobster fisheries that depend on them. Warmer water also stresses farmed salmon in summer. Tasmania has also experienced severe bushfires, including fires that have burned ancient, fire-sensitive Gondwanan vegetation in the Tasmanian Wilderness World Heritage Area, vegetation that may not recover.
Meeting the needs of the present without compromising the ability of future generations to meet their own needs (the Brundtland definition, 1987). It is commonly assessed across three interdependent dimensions: environmental, social and economic.
To assess sustainability, geographers use frameworks and indicators. The three pillars (environment, society, economy) or the "triple bottom line" judge whether an activity supports all three over the long term. The ecological footprint measures the biologically productive land and water needed to support consumption and absorb waste, compared with available biocapacity; when footprint exceeds biocapacity, the use is unsustainable. The planetary boundaries framework identifies thresholds, such as for climate change and biodiversity loss, beyond which Earth systems may shift dangerously. The United Nations Sustainable Development Goals provide a global set of targets and indicators.
The strengthening East Australian Current is extending warmer water further south, making eastern Tasmania one of the fastest-warming marine regions on Earth. This single driver links global climate change to local impacts on kelp, urchins and fisheries.
A useful approach in answers is to distinguish causes, impacts and responses, and to apply a sustainability lens explicitly. For any change, ask: what is the natural baseline, what human drivers are operating, what are the environmental, social and economic consequences, and is the current use within ecological limits? Strong responses quantify change where possible and recognise that sustainability involves trade-offs between competing values and time scales.
Sustainability questions often supply per-capita footprint and biocapacity figures. Work the comparison in steps.
Step 1: identify the two quantities
Ecological footprint is the productive land and water needed to support a population's consumption and absorb its waste, measured in global hectares per person. Biocapacity is the productive land and water actually available, in the same units.
Step 2: compute the balance
Subtract biocapacity from footprint. If footprint is global hectares per person and biocapacity is , the deficit is global hectares per person.
Step 3: judge sustainability
A footprint larger than biocapacity is an ecological deficit, meaning consumption exceeds what local systems can regenerate, which is unsustainable and relies on imports or drawing down natural capital.
Step 4: qualify the conclusion
Note the limitation: one aggregate number hides which resources are over-used and ignores social and economic dimensions, so pair it with another indicator before judging.
Sustainability is not only about protecting nature. It balances environmental health, social wellbeing and economic viability together. A response that ignores jobs and communities, or one that ignores ecological limits, is incomplete. Always weigh all three dimensions and the long-term time horizon.
Exam-style questions
Questions in the style of TASC exam questions on this dot point, each with a worked answer. They are written by ExamExplained unless tagged "Past paper"; the year shows the paper a question is modelled on.
Practice8 marksUsing sea surface temperature data for eastern Tasmania from 1950 to 2020, describe the trend and explain how this environmental change affects local marine ecosystems.Show worked answer →
An 8 mark source-and-explain answer needs a quantified trend then a causal chain.
Describe the trend. State that sea surface temperature rises over the period, and quote figures from the graph (for example a warming of roughly two to four times the global average, naming start and end values). Note that eastern Tasmania is a global ocean-warming hotspot.
Explain the impact. Link warming, driven by the strengthening East Australian Current, to the southward spread of the long-spined sea urchin, which overgrazes giant kelp forests and creates barren reefs, harming biodiversity and the abalone and rock-lobster fisheries. Warmer water also stresses farmed salmon in summer.
Markers reward quoting the graph, naming the East Australian Current, and a clear cause-and-effect sequence to named species and industries.
Practice10 marksExplain how sustainability is assessed, and discuss the usefulness of two frameworks or indicators used to measure it.Show worked answer →
A 10 mark response defines sustainability then evaluates two tools.
Definition. Give the Brundtland definition and the three interdependent dimensions (environmental, social, economic).
Two tools. Choose two of: the triple bottom line, the ecological footprint compared with biocapacity, the planetary boundaries framework, or the Sustainable Development Goals. For each, explain what it measures and one strength and one limitation. For example, the ecological footprint usefully shows when consumption exceeds biocapacity but oversimplifies complex systems into one number.
Discuss usefulness. Conclude that no single indicator is complete, so using several together gives a more reliable picture. Markers reward correct definition, accurate description of each tool, and balanced evaluation.