Chapter 10: Environmental Sustainability

10.1 Threats to the Environment

• Environmental sustainability means the environment remains unchanged without depletion of natural resources, with assured quality over a long period. (p.202)
• Climate change refers to changes in earth temperature, rainfall distribution and wind patterns, linked to the greenhouse effect. (p.203)
• Greenhouse gases (carbon dioxide, methane, nitrogen oxide, CFC) absorb infrared rays reflected from earth and keep the earth warm. (p.203)
• Human activities such as burning fossil fuels, deforestation, animal farming and fertiliser use increase greenhouse gases and cause global warming. (p.204)
• Negative effects of global warming include melting ice raising sea levels, extreme weather, and loss of flora and fauna. (p.203)
• Deforestation clears trees for timber, mining, agriculture and construction; it causes soil erosion, flash floods, climate change, loss of biodiversity and disruption of nutrient cycles. (p.204)
• Eutrophication occurs when excess nitrate and phosphate enter water, causing algal blooms, reduced light penetration and oxygen depletion. (p.206)
• Decomposers in eutrophic water increase biochemical oxygen demand (BOD); a high BOD means poor water quality. (p.206)
• Sources of nitrate and phosphate include farms, construction sites, terrace house detergents and untreated sewage. (p.206)
• Air pollution increases from smog, vehicle exhaust, factory smoke and open burning; pollutants include sulphur dioxide, nitrogen oxide, carbon monoxide and soot. (p.208)
• Thermal pollution occurs when heated water from factories and power plants lowers dissolved oxygen and endangers aquatic life. (p.209)
• Acid rain forms when nitrogen oxide and sulphur dioxide combine with water vapour to form nitric and sulphuric acid; it makes soil infertile and kills plankton and fish. (p.209)
• Noise pollution is sound that harms the health of humans and animals, causing high blood pressure, depression and headaches. (p.210)
• Population growth increases demand for resources, leading to deforestation, loss of biodiversity and global warming. (p.210)

10.2 Preservation, Conservation and Restoration of Ecosystem

• Preservation protects ecosystem components so they remain in their natural condition, e.g. gazetting forests as reserves. (p.212)
• Conservation restores and saves environmental resources such as water, forest, energy and air so they continue to exist. (p.212)
• Restoration renews ecosystems that have been degraded, damaged or destroyed, e.g. reforestation and planting cover crops. (p.212)
• In situ conservation keeps species in their original habitat, e.g. natural parks; ex situ conservation keeps them outside, e.g. zoos and botanical parks. (p.212)

10.3 Practices in Environmental Sustainability

• Renewable energy comes from the sun, wind, waves, water, geothermal and biomass sources and is cleaner and safer. (p.214)
• The 5R concept: Rethink, Repair, Reuse, Reduce, Recycle. (p.214)
• Environment-friendly transport includes bicycles, hybrid and electric vehicles, carpooling and public transport. (p.214)
• Electricity from burning fossil fuels releases pollutants, so electricity should be used wisely. (p.214)
• The Department of Environment coordinates waste disposal, sets limits on waste production and controls licences for waste products. (p.215)
• Upcycling reduces waste sent to landfill sites. (p.215)
• Biological control uses natural enemies to control pests and reduces the use of pesticides. (p.215)
• Water saving includes collecting rainwater and reusing water for plants and washing vehicles. (p.215)

10.3.2 Food Security

• Food security means assured availability of food, sufficient access to food, and safe food utilisation. (p.217)
• The four components of food security are availability, access, utilisation and stability. (p.217)
• Halal, Good Manufacturing Practices (GMP) and Hazard Analysis and Critical Control Points (HACCP) emphasise hygienic and safe food production. (p.217)
• National Agro-Food Policy (NAP) 2012 is a government effort to achieve food security. (p.216)

10.4 Green Technology

• Green technology develops products, equipment and systems that preserve the environment while reducing the negative impacts of human activities. (p.218)
• Products are classified as green technology if they minimise environmental degradation, use energy and resources efficiently, use renewable resources, and have low or zero greenhouse gas release. (p.219)
• The National Green Technology Policy (NGTP), launched in 2009, has four pillars: energy, environment, economy and social. (p.219)
• Green buildings use natural resources efficiently, e.g. solar panels, rainwater catchment and recycled materials. (p.220)
• Biological control agents such as parasitic wasps are used to control pests on highland vegetables. (p.200)
• Eco-enzymes made from fruit waste can be used as cleaning agents. (p.222)
• Biogas can be produced from organic solid waste. (p.221)
• Environmental education aims to raise awareness, provide knowledge, build skills and encourage care for the environment. (p.222)
• Local Agenda 21 is a programme in which the private sector, local authorities and communities plan sustainable development that balances social, economic and environmental needs. (p.216)