Managing resources

Food security and the causes of food insecurity

Food security exists when all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food that meets their dietary needs and food preferences for an active and healthy life. Notice the definition has four ideas running through it: enough food must be available, people must be able to reach and afford it, the food must be safe and nutritious, and this must hold at all times, not just in a good harvest. A country can grow a surplus of food and still contain hungry people, because access and poverty matter just as much as production.

Food insecurity is the opposite state, and exam questions usually ask you to link a cause to a breakdown in one of those four ideas. Population growth raises demand faster than supply, and poverty stops people affording food even when the shops are stocked. Unsustainable production and an increase in the homogeneity of the global food supply are two sides of the same risk: intensive farming mines the soil while the world relies on a shrinking handful of crop varieties, so one disease can threaten the whole supply.

Several causes are environmental rather than economic. Land degradation through erosion, salinisation and desertification reduces the area that can grow anything; water shortages and drought do the same; and climate change makes rainfall less reliable and extreme weather more frequent. Agricultural disease can wipe out a crop or a herd, while diverting crops for biofuels and price setting (speculation and export restrictions) take food out of the food chain or push its price beyond what poor households can pay.

• Population growth and poverty
• Unsustainable production and increased homogeneity of the global food supply
• Price setting, speculation and export restrictions
• Land degradation and water shortages
• Agricultural disease
• Diverting crops for biofuels
• Climate change

The impacts of food insecurity

The impacts follow in a chain, and a good answer follows the chain rather than listing. Regional food scarcity means some places simply do not have enough food while other regions hold a surplus; the shortage is uneven, not universal. Shortage becomes nutritional deficiency and malnutrition, because people may eat enough calories yet still lack protein, iron or vitamins, and this is worst for children, whose growth and brain development depend on a balanced diet.

Malnutrition feeds back into poverty, because hungry, ill people cannot work or learn, and a household trapped in that cycle is more likely to move in search of food. Forced migration carries people into camps or cities where the food shortage follows them, and competition over scarce food and land can tip into conflict.

The end of the chain is the worst: acute food shortage becomes famine, and famine brings death, both directly through starvation and indirectly through the diseases a weakened population cannot resist. Examiners reward you for using the syllabus words (scarcity, malnutrition, poverty, forced migration, conflict, famine, death) in that cause-and-effect order.

• Regional food scarcity
• Nutritional deficiency and malnutrition
• Poverty
• Forced migration
• Conflict
• Famine and death

Strategies for managing food security

Strategies split into growing more food and distributing what is grown more fairly. Subsistence agriculture keeps households fed from their own land and protects them from price shocks, even though it yields little surplus. Intensification raises output from the same land through more fertiliser, irrigation and high-yield varieties, while extensification brings new land into production, though extensification often means clearing forest or draining wetlands.

Improved agricultural techniques and efficiency is the biggest bank of marks. Aquaculture farms fish and shellfish, and hydroponics grows plants in a nutrient solution instead of soil, so both produce food where land is scarce or poor. Selective breeding and genetically modified (GM) crops develop pest-resistant varieties and higher-yielding crops, and controlling limiting factors - adding fertilisers where nutrients are short - removes the one thing holding growth back.

Productivity rises further by removing what competes with the crop: herbicides kill weeds, fungicides reduce fungal disease, and biological control uses a pest's natural enemies instead of chemicals. Reducing livestock in favour of growing crops makes better use of land, because plants fed directly to people feed more of them than plants fed to animals first.

Distribution strategies matter as much as production. Reducing food waste, large-scale food stockpiling, improving transport to reach remote regions, and protecting pollinating insects (which many crops depend on) all keep more of the food that is grown. The World Food Programme distributes food aid in emergencies, and rationing shares out what little food there is fairly during a crisis.

Energy resources: renewable and non-renewable

An energy resource is classified by whether the supply replaces itself on a human timescale. Non-renewable resources exist in a fixed amount and are used faster than they form, so they will one day run out: fossil fuels (oil, natural gas and coal) took millions of years to form from buried organic matter, and nuclear energy burns uranium, a finite mineral fuel. Renewable resources are replenished naturally and continuously, so in principle they cannot be exhausted.

The renewable list is the one to memorise. Biofuels are biomass used for energy - wood, bioethanol (fermented from crops) and biogas (from decaying organic waste). Geothermal energy taps heat from inside the Earth, hydroelectric dams use falling water, and tidal and wave energy use the movement of the sea. Solar energy captures sunlight and wind energy captures moving air.

The split matters because every strategy for energy security is built on it: non-renewables are cheap and reliable now but finite and polluting, while renewables are cleaner and endless but often intermittent and expensive to build. A wind farm produces no electricity on a still day, which is why energy security needs a mix of sources, not a single one.

Energy security and the causes of energy insecurity

Energy security is the reliable availability of energy sources at an affordable price, with consideration of the environmental impacts. It has two timescales. Long-term energy security means the supply is in line with economic development and environmental needs over years and decades, while short-term energy security means the system can react promptly to sudden changes in the supply-demand balance, such as a cold snap or a pipeline failure.

The causes of energy insecurity are a mix of geology, economics and politics. Fossil fuel depletion means the cheapest, easiest reserves are used first, so what remains is harder and dearer to extract. Inequality in global energy resources concentrates oil, gas and coal in a few regions while others have almost none, and population growth plus the differing energy needs of countries in different income groups push global demand up faster than supply.

Climate change makes energy insecure in two directions at once: extreme weather such as drought and storms can knock out power stations and supply lines, while the need to cut emissions pushes countries away from the fossil fuels they currently rely on. Finally supply disruption - from natural disasters, piracy or terrorism - can cut a supply line overnight, and a country that depends on a single source or a single route is the most exposed.

• Fossil fuel depletion
• Inequality in global energy resources
• Population growth and differing energy needs of different income groups
• Climate change
• Supply disruption from natural disasters, piracy and terrorism

Impacts of energy insecurity and strategies for managing it

The impacts start with supply and spread through the whole economy. Disrupted electricity supply to homes and industry stops factories and hospitals at once, and scarcity raises prices for energy resources. Higher energy prices feed into increasing costs for industry, and firms that cannot pay cut production, bringing job losses and economic recession.

The human cost is the one to emphasise: increased poverty and low standards of living, as households choose between heating and food, and reliance on imported sources of energy leaves a country's economy hostage to the price and politics of its suppliers. Civil disruption and conflict follow when people cannot afford to heat or power their homes, and countries have gone to war over access to energy.

Strategies for managing energy security mirror the causes. Increasing energy efficiency cuts demand so the same supply goes further, and increasing energy production adds to supply. Reducing reliance on fossil fuels, investing in renewable resources and carbon-neutral fuels, and developing alternative energy technologies diversify the mix so no single source can fail catastrophically. Investment in local energy projects, such as small solar or wind schemes, makes communities less dependent on distant supplies, and rationing shares a short supply fairly in a crisis.

Methods of waste disposal and their impacts

Landfill sites bury waste in the ground; incineration burns it; storage holds it, often in sealed facilities, waiting for treatment; disposal at sea dumps it in the ocean; recycling recovers materials to make new products; and exporting waste ships it to another country for disposal. Each method carries its own set of impacts, and exam questions ask you to link a method to its specific impact, not to recite a generic list.

Landfill is the richest source of marks. As the buried waste decays it produces a liquid called leachate, and contamination of soil from this can lead to leaching and contamination of groundwater - the water people drink. The same decay builds up methane (CH4), a greenhouse gas, and if it collects in buildings it creates a danger of explosions. Landfill is also a source of visual and noise pollution and unpleasant odour, and unmanaged waste attracts rats and flies, raising the risk of spread of disease.

Incineration avoids burying waste but releases toxic substances such as dioxins unless the gases are carefully scrubbed, and it produces ash that still needs disposal. Waste dumped at sea, and plastic waste anywhere, breaks into plastics and microplastics in oceans, which marine animals eat. Toxic metals that enter the food chain undergo bioaccumulation (building up in one organism) and biomagnification (becoming more concentrated at each higher trophic level), so a predator ends up far more contaminated than the water it lives in.

• Landfill: leachate, groundwater contamination, methane and explosion risk, odour and vermin
• Incineration: toxic emissions and ash that still needs disposal
• Disposal at sea and plastics: microplastics in oceans
• All methods: visual and noise pollution and risk of disease
• Toxic substances: bioaccumulation and biomagnification up the food chain

Strategies to reduce the impacts of waste disposal

The waste hierarchy is reduce, reuse and recycle, in that order of preference. Reducing waste at source means there is simply less to dispose of; reusing items such as refillable bottles and second-hand goods keeps them out of the waste stream; and recycling reprocesses materials such as glass, metal and paper into new products, saving both resources and landfill space.

Biological strategies turn waste into a resource. Biodegradable plastics break down naturally instead of persisting as microplastics. Food waste can become animal feed, and composting lets organic waste rot under controlled conditions into a soil improver. Fermentation uses microorganisms to break waste down, and using waste to generate energy, by burning it or capturing landfill methane as biogas, gets useful power out of material that would otherwise just sit there.

Behaviour change needs a push. Education teaches people to waste less and sort their recycling, while financial incentives such as deposit schemes and landfill charges, and legislation such as bans on single-use plastics and recycling targets, make the right choice the easy or the only one. A strategy earns its mark when you say what it reduces and why: composting diverts organic waste from landfill, so less methane is produced and less leachate threatens groundwater.