AQA GCSE Geography (8035) — Challenges in the human environment
You can buy conventional carrots in a supermarket for 60p, but choosing the organic equivalent will often cost you 66% more. This price difference highlights the delicate balance between producing enough food to feed a growing population and protecting our natural environment. Food Security exists when all people at all times have physical, social, and economic access to sufficient, safe, and nutritious food. Conversely, Food Insecurity is the lack of consistent access to enough food for an active, healthy life. To tackle global hunger, we must develop a Sustainable Food Supply. This means producing food in a way that maintains soil, water, and the environment for future generations while remaining socially and economically viable. Alongside sustainable farming, reducing waste is critical, as 30–40% of all food produced globally is currently wasted.
Organic Farming relies on natural cycles, like crop rotation, rather than synthetic chemicals to maintain soil fertility. It prohibits synthetic fertilisers and permits only around 15 natural pesticides, compared to approximately 300 synthetic varieties used in conventional agribusiness. Environmentally, organic farming is highly beneficial. It supports 50% more wildlife, 30% more species, and results in soil containing 20% more organic matter. Furthermore, widespread adoption in the UK could offset 23% of the country's agricultural greenhouse gas emissions. However, it suffers from a significant Yield Gap, producing 19–20% lower yields on average than conventional farming (and up to 50% lower for crops like wheat). Because of this lower efficiency, organic farming occupies just 2.1% of global agricultural land and provides less than 2% of the global calorie supply. Organic crops also have a -15% temporal stability, meaning year-to-year yields fluctuate more due to weather and pests. This lower yield and higher labour requirement (such as mechanical weeding) create an economic barrier for consumers.
Calculate the percentage price increase of organic carrots (£1.00) compared to conventional carrots (60p).
Step 1: Write out the formula for percentage change.
Step 2: Substitute the values into the formula.
Step 3: Calculate the final percentage.
Urban Farming is the practice of cultivating, processing, and distributing food in or around towns and cities. A prime example is Incredible Edible Todmorden in the UK, where 5,000 out of 17,000 residents grow food in "help-yourself" beds on derelict land. Urban farming drastically reduces Food Miles and is highly space-efficient. Research shows small-scale urban soil plots achieve a mean yield of annually, compared to for conventional open-field commercial farming. Despite high yields per square metre, urban farming can have a carbon footprint 6 times higher than conventional farming if low-tech infrastructure (like raised beds and plastic tunnels) is replaced frequently rather than using circular waste streams. Permaculture is another sustainable system that mimics patterns observed in natural ecosystems using techniques like rainwater harvesting and biological pest control (e.g., ladybirds). It prioritises long-term soil health and uses zero chemicals, but it is highly labour-intensive and difficult to scale globally. Overall, while sustainable methods excel in biodiversity and local efficiency, feeding a global population of 10 billion exclusively organically would require a massive expansion of agricultural land, likely leading to further deforestation.
To counter the yield gaps of sustainable soil farming, technological solutions are increasingly used in vertical urban farms. Hydroponics grows plants in a nutrient-enriched water solution without soil. It uses 70–90% less water than traditional farming because the water is recycled within a closed system, and it can be up to 15 times more productive per square metre. Similarly, Aeroponics suspends plant roots in the air, periodically spraying them with a nutrient-rich mist. While these methods drastically increase yields and improve food security, they do NOT rely on natural cycles and require significant initial investment and energy for artificial lighting and climate control.
Large-scale, top-down agricultural projects often fail in Lower Income Countries (LICs). Instead, bottom-up approaches using Appropriate Technology—small-scale, affordable tools suited to local skills and materials—are far more sustainable. Makueni County is a semi-arid region in Kenya with 885,000 residents and a low, unreliable rainfall of just 500mm/year. In 2014, the Makueni Food and Water Security Programme was launched by charities and the local community to construct Sand Dams. A sand dam is a reinforced masonry wall (around 1m high) built across a seasonal riverbed. Crucially, it does NOT use expensive imported parts or require specialist engineers to maintain. During the rainy season, water washes sand downstream, trapping it behind the concrete wall. Water is securely stored in the pores of the sand, holding up to 40% of the sand's volume (up to 40 million litres per dam). Because the water is stored up to 1m below the surface of the sand, it does NOT evaporate and is naturally filtered, protecting the community from waterborne diseases like cholera. This stored water is extracted via shallow wells or pipes and used for irrigation. Economically, this increases crop yields of maize, beans, millet, and sorghum significantly, allowing farmers to sell their surplus at local markets for extra income. Socially, the scheme saves residents 2–8 hours daily that was previously spent fetching water, which directly increases school attendance and improves long-term community resilience. Environmentally, the sand dams raise the local water table (aquifer recharge), which allows for natural plant growth and supports the wider ecosystem.
Students often confuse strategies that "increase food supply" (like high-tech hydroponics) with "sustainable food production" (like organic farming). Hydroponics relies heavily on artificial energy, meaning it is not always environmentally sustainable!
When a question asks you to 'Evaluate' organic or urban farming, examiners expect a balanced argument. You must discuss their environmental benefits but explicitly contrast these with the economic costs and lower global yields.
In 'Explain' questions about local schemes like Makueni County, do not just describe how a sand dam works. You must provide a causal chain linking the technology to food security (e.g., sand dam traps water -> enables year-round irrigation -> increases crop yields -> creates market surplus) and clearly outline the social, economic, and environmental outcomes.
Food Security
When all people at all times have physical, social, and economic access to sufficient, safe, and nutritious food.
Food Insecurity
A lack of consistent access to enough food for an active, healthy life.
Sustainable Food Supply
Producing food in a way that ensures soil, water, and the environment are maintained for future generations while remaining socially and economically viable.
Organic Farming
A method of production relying on natural cycles rather than synthetic chemicals to maintain soil fertility.
Yield Gap
The difference between the actual yield of a crop (e.g., organic) and the maximum potential yield achieved under conventional or intensive conditions.
Urban Farming
The practice of cultivating, processing, and distributing food in or around a village, town, or city.
Food Miles
The distance food travels from its place of production to the consumer.
Permaculture
A sustainable agricultural design system based on mimicking the patterns and features observed in natural ecosystems.
Hydroponics
A technological method of growing plants using mineral nutrient solutions in water, without soil.
Aeroponics
A high-tech system of growing plants in an air or mist environment without the use of soil or an aggregate medium.
Appropriate Technology
Small-scale, affordable, and simple technology suited to the skills and needs of a local community, using local materials.
Sand Dam
A reinforced masonry wall built across a seasonal sandy river that captures and stores water in the pores of the sand.
Put your knowledge into practice — try past paper questions for Geography
Food Security
When all people at all times have physical, social, and economic access to sufficient, safe, and nutritious food.
Food Insecurity
A lack of consistent access to enough food for an active, healthy life.
Sustainable Food Supply
Producing food in a way that ensures soil, water, and the environment are maintained for future generations while remaining socially and economically viable.
Organic Farming
A method of production relying on natural cycles rather than synthetic chemicals to maintain soil fertility.
Yield Gap
The difference between the actual yield of a crop (e.g., organic) and the maximum potential yield achieved under conventional or intensive conditions.
Urban Farming
The practice of cultivating, processing, and distributing food in or around a village, town, or city.
Food Miles
The distance food travels from its place of production to the consumer.
Permaculture
A sustainable agricultural design system based on mimicking the patterns and features observed in natural ecosystems.
Hydroponics
A technological method of growing plants using mineral nutrient solutions in water, without soil.
Aeroponics
A high-tech system of growing plants in an air or mist environment without the use of soil or an aggregate medium.
Appropriate Technology
Small-scale, affordable, and simple technology suited to the skills and needs of a local community, using local materials.
Sand Dam
A reinforced masonry wall built across a seasonal sandy river that captures and stores water in the pores of the sand.
