Sustainability and Recycling Decisions

Sustainability Concepts

Sustainability means using resources in a way that meets current needs without harming the ability of future generations to meet theirs. It involves careful management of natural resources to avoid depletion and environmental damage.

Finite resources are natural resources that cannot be replaced once used, such as fossil fuels (coal, oil, natural gas) and many metals. Renewable resources can be replenished naturally over time, like sunlight, wind, and timber (if managed properly).

Using finite resources excessively leads to environmental problems like pollution, habitat destruction, and climate change. Sustainable use aims to reduce these impacts by conserving resources and reducing waste.

Life Cycle Assessment (LCA)

A Life Cycle Assessment (LCA) evaluates the environmental impact of a product throughout its entire life, from raw material extraction to disposal. This helps identify ways to reduce harm and improve sustainability.

The main stages of an LCA are:

• Raw materials: Extracting natural resources needed for the product.
• Manufacture: Processing and making the product, which uses energy and may produce waste.
• Use: The product6s lifespan and how it affects the environment during use.
• Disposal: How the product is discarded, recycled, or decomposed at the end of its life.

By evaluating each stage, companies can reduce the carbon footprint1 the total greenhouse gases produced. For example, using recycled materials in manufacture often lowers energy use and emissions.

For instance, producing aluminium from recycled cans uses about 95% less energy than extracting it from bauxite ore.

Example: If manufacturing a product from raw materials produces 100 kg of CO₂, but using recycled materials reduces this to 20 kg, the carbon footprint is reduced by 80%.

Recycling Metals

Recycling metals is important because metals are finite resources and mining new metals uses a lot of energy and causes environmental damage.

Benefits of recycling metals:

• Uses less energy than extracting and processing new metals.
• Reduces mining waste and habitat destruction.
• Conserves finite metal ores.
• Reduces greenhouse gas emissions.

Common recyclable metals include aluminium, steel, copper, and iron. Aluminium is especially valuable to recycle because producing it from ore requires a lot of electricity.

Example: Recycling 1 tonne of aluminium saves about 14,000 kWh of electricity compared to making the same amount from bauxite ore.

Recycling Plastics

Plastics are widely used but cause serious environmental problems because they are mostly made from finite fossil fuels and can take hundreds of years to decompose.

Types of plastics recycled: Commonly recycled plastics include PET (used in drink bottles), HDPE (milk containers), and PP (food packaging).

Challenges in plastic recycling:

• Different types of plastics must be separated before recycling.
• Contamination from food or other materials can spoil batches.
• Some plastics degrade in quality after recycling, limiting reuse.

Alternatives to traditional plastics: Biodegradable polymers break down more quickly in the environment and are made from renewable resources like plants. Examples include polylactic acid (PLA) made from corn starch.

Using biodegradable plastics reduces long-term pollution but they still require proper disposal conditions to break down effectively.

Making Sustainable Decisions

The reduce, reuse, recycle hierarchy guides sustainable choices:

• Reduce: Use fewer resources and create less waste.
• Reuse: Find new uses for items instead of throwing them away.
• Recycle: Process waste materials to make new products.

Reducing and reusing are better for the environment than recycling because they save more energy and resources.

Economic and environmental trade-offs must be considered. For example, producing a new product from recycled materials may cost more but saves energy and reduces pollution.

Choosing sustainable materials means selecting those with low environmental impact, long life, and good recyclability. For example, glass can be recycled many times without losing quality, making it more sustainable than some plastics.

Example: Choosing a reusable water bottle instead of single-use plastic bottles reduces plastic waste and saves resources over time.

Example calculation: If a product's carbon footprint is reduced from 100 kg CO₂ to 20 kg by recycling, the percentage reduction is calculated as ((100 - 20) / 100) x 100 = 80% reduction.