Evaluate the environmental impacts and sustainability of resource extraction, including but not limited to mining methods, rehabilitation, life cycle assessment and the management of renewable and non-renewable resources in the Australian context

What this dot point is asking

NESA wants you to evaluate, not just describe, how resources are extracted and whether that extraction is sustainable. You need to distinguish renewable from non-renewable resources, weigh the environmental impacts of mining against its benefits, and discuss management tools such as rehabilitation and life cycle assessment, using Australian examples.

The answer

Sustainability means meeting present needs without compromising the ability of future generations to meet theirs. Applied to resources, it requires balancing the economic benefit of extraction against its environmental and social costs.

Renewable and non-renewable resources

Non-renewable resources, such as coal, oil, gas and metal ores, form over geological timescales and are effectively finite on a human timescale; once used, they are gone. Renewable resources, such as solar energy, wind, water and timber, are replenished naturally, although they can still be degraded if harvested faster than they regenerate. Managing non-renewables sustainably means using them efficiently, recycling where possible, and developing alternatives, while managing renewables means keeping harvest within the rate of natural replacement.

Mining methods and impacts

Open-cut mining, used for Australia's shallow iron ore in the Pilbara and much of its coal, removes overburden to expose the ore. It is cheap and efficient but disturbs large areas, generates dust and noise, and can lower water tables. Underground mining disturbs less surface but is more dangerous and can cause subsidence. The impacts of mining include the clearing of vegetation and habitat, the production of large volumes of waste rock and tailings, acid mine drainage when sulfide minerals react with air and water to release acid and dissolved metals, and the consumption and contamination of water. These impacts must be weighed against the economic benefits: mining is a cornerstone of the Australian economy and supports regional employment and export income.

Rehabilitation

Rehabilitation aims to return a mined site to a stable, productive and self-sustaining state. It typically involves reshaping the landform, replacing stored topsoil, revegetating with native species and managing water quality. Australian law requires companies to lodge financial bonds and rehabilitation plans before mining begins, so that funds exist to restore the land even if a company fails. Progressive rehabilitation, restoring parts of a site while others are still being mined, reduces the total disturbed area at any time. Rehabilitation is rarely perfect; restored ecosystems may differ from the original, and some impacts, such as a permanently altered landform, cannot be fully reversed.

Life cycle assessment

Life cycle assessment evaluates the total environmental impact of a resource or product across its entire life, from extraction through processing, transport, use and disposal or recycling. It prevents decisions that simply shift impacts from one stage to another. For example, assessing aluminium must include not only bauxite mining but the very large energy used in smelting; recycling aluminium uses a small fraction of that energy, so life cycle assessment strongly favours recycling. Applying this thinking helps compare options on a fair, whole-of-life basis.

The Australian context

Australia's economy depends heavily on resource exports, especially iron ore and coal, which creates tension between economic benefit and environmental sustainability. The shift away from thermal coal as the world decarbonises raises questions about the long-term future of coal regions such as the Hunter Valley and the need to plan for transition. At the same time, Australia has abundant renewable resources: high solar exposure and strong wind make large-scale solar and wind generation increasingly competitive, and Australia is positioning itself as a potential exporter of renewable energy and critical minerals such as lithium needed for batteries. Sustainable resource management therefore means both rehabilitating existing mines and steering investment toward renewables and recycling.

Try this

Q1. Evaluate the sustainability of open-cut coal mining in Australia. [6 marks]

• Cue. Weigh economic benefits (exports, regional jobs) against impacts (habitat loss, emissions, water, finite resource) and reach a justified judgement that references the global shift away from coal.

Q2. Explain how a life cycle assessment could change a decision about whether to use new or recycled aluminium. [3 marks]

• Cue. Assessing the full life cycle reveals the enormous energy used in smelting new aluminium from bauxite, so recycling, which uses a fraction of that energy, is favoured.