Sustainability of the Environment

This chapter asks why solar cells have a carbon footprint, why plastic bags are being replaced with paper bags, whether electric cars are zero-emission vehicles, and which international organisations address environmental issues p. 90. Upcycle is a recycling process that produces new products of higher value than the original, such as a sofa made from recycled waste paper p. 91.

3.1 Product Life Cycle

Carbon footprint refers to the total amount of carbon dioxide released into the atmosphere as a result of the activities of an individual, event, organisation, community or products used in daily life p. 92. Energy efficiency labels relate to the carbon footprint of electrical appliances, and a carbon footprint label on a food product may show that 900 g of carbon dioxide is released for every 500 ml p. 92. In Activity 3.1, an LED lamp of 0.009 kW used for 5 hours uses 0.045 kWh and releases 0.0351 g of carbon dioxide, assuming 50 kWh produces 39 g p. 93.

The carbon footprint of a product refers to its negative impacts on environmental sustainability throughout its life cycle, and its carbon handprint to its positive impacts p. 94. Carbon handprint steps include replacing non-renewable building materials such as cement with renewable ones such as timber, and extending the life cycle of products such as rechargeable batteries and solar panels p. 94. Hydroelectric power stations such as the Bakun hydroelectric power station use renewable energy sources and do not emit greenhouse gases p. 95. The 5R concept (Refuse, Reduce, Recycle, Reuse, Rot) reduces waste, and carbon sinks such as forests and oceans remove carbon dioxide from the air p. 95.

The common life cycle of a product starts from source and ends in disposal, either through recycling (cradle-to-cradle life cycle) or decay (cradle-to-grave life cycle) p. 96. Upcycle is an efficient way to manage plastic waste, such as making a plastic broom from used plastic bottles p. 97. Plastic pollution harms the environment, wildlife and humans because most plastics withstand the natural decomposition process p. 98. According to NOAA, microplastics are plastic pieces less than 5 mm in length from bottles, man-made textiles, paint and discarded electronic devices p. 98. Microplastics pass through the food web until they end up in humans and marine mammals, and reducing plastic waste helps solve this p. 99.

3.2 Environmental Pollution

Environmental pollution refers to unwanted changes in the physical, chemical or biological characteristics of air, water and soil, and it causes harm and discomfort to all life forms p. 99. Air pollution comes from burning fossil and biomass fuels, automobile exhaust gases and natural sources such as volcanic eruptions, forest fires and dust storms p. 100. Water pollution comes from detergents, sewage, industrial grease, fertilisers, pesticides and oil spills, and land pollution from solid waste, acid rain, nuclear waste and electronic waste p. 100. Thermal pollution comes from deforestation, industrial activities and fuel combustion in vehicles or machines p. 100.

The Air Pollutant Index (API) measures air pollution level, while Biochemical Oxygen Demand (BOD) measures water pollution level p. 101. Eutrophication is the response of an aquatic ecosystem to extra phosphate ions and nitrate ions from detergents, fertilisers and garbage, which makes algae grow rapidly and reduces oxygen in the water p. 101. BOD is the amount of dissolved oxygen needed by microorganisms to decompose organic substances in water, so a higher BOD means more microorganisms p. 102. The more polluted a water sample, the faster methylene blue solution decolourises in it p. 102. Effective microorganism mud balls (EM mud balls) are a Green Technology method used to treat contaminated rivers in Malaysia p. 103. EM contains lactic acid bacteria (Lactobacillus casei), photosynthetic bacteria (Rhodopseudomonas palustris) and yeast (Saccharomyces cerevisiae) p. 104.

3.3 Preservation and Conservation of the Environment

Figure 3.10 shows the carbon dioxide content in the atmosphere from 2006 till 2019, and every individual needs to play a role in reducing it p. 105. Negative Emission Technologies remove carbon dioxide from the atmosphere, for example marine microalgae that reduce carbon dioxide through photosynthesis p. 106. Eco currency is a proposed universal currency used as a medium of exchange to help maintain environmental balance p. 106. Green Technology is used in solar technology, green buildings, zero carbon emission, biodiesel and hybrid cars p. 107.

The United Nations (UN) addresses global environmental issues by sponsoring conferences and agreements on climate change, securing clean drinking water, banning chlorofluorocarbon to protect the ozone layer, and banning toxic chemicals such as DDT pesticides p. 108. These include the Rio Conference (UNCED) in 1992, the Kyoto Protocol in 1997 to reduce greenhouse gas emissions, and the Paris Agreement in 2016 to limit the rise in global temperature to 1.5 °C p. 108.