Secondary 2 Geography

All people at all times have enough safe, nutritious food; its four pillars are availability, affordability, stability and food safety.

A long-term shortage of energy and nutrients in the diet, leaving people weak, ill and stunted.

The UN agency for food and agriculture; it compiles global food data and promotes farming and relief.

A region that produces and exports large amounts of grain, such as the North American Plains.

Output per unit of farmland, usually in tonnes per hectare; it shows how productive farming is.

Supplying water to crops by artificial means, reducing reliance on rainfall and steadying yields.

In geography, how a phenomenon is arranged in space; in food issues, also how food is shared among people.

Africa south of the Sahara — the region with the world's highest rate of undernourishment, about one in five people.

Buying food from abroad when local production falls short; imports are at risk when routes are disrupted.

A disaster in which a large population faces prolonged food shortage, severe undernourishment and death.

A prolonged shortfall of rain far below normal, drying soils and ruining crops.

The semi-arid belt south of the Sahara with low, unreliable rainfall — a hotspot of drought and food crises.

A disaster in which swarming locusts strip crops; the 2019 to 2021 desert locust outbreak left millions short of food in East Africa.

Winds that reverse with the seasons and bring the rains; South Asian farming depends on them, and too much or too little brings disaster.

War between armed groups within one country; it destroys farming, transport and aid — a key human cause of modern famine.

Enough food exists overall, but poverty, markets and transport keep it from those who need it.

The Indian economist and Nobel laureate who showed that modern famines stem from people losing access to food, not from a global lack of it.

When harvests fall far below normal — the first link in the chain leading to famine.

Crops given chosen genes for traits such as pest resistance, drought tolerance or better nutrition, e.g. Golden Rice.

GM rice carrying genes that make vitamin A; named for its golden colour, it fights vitamin A deficiency.

Growing plants in nutrient solution without soil, using about one-tenth of the water of conventional farming.

Stacking crops in layers inside buildings — land- and water-saving farms close to city consumers.

The UN agency for food aid, feeding over 100 million people each year in emergencies.

Farming that meets today's food needs while protecting soil, water and ecosystems for future generations.

Growing different crops in turn (or leaving land fallow) so the soil recovers its nutrients.

Piping water drop by drop straight to plant roots, saving 30 to 70 percent of water.

Farming without synthetic fertiliser or pesticide, relying on compost and natural pest control.

Water of the oceans and salt lakes, about 97.5% of all water — undrinkable and unfit for irrigation.

Water with very little salt — just 2.5% of the total, held in glaciers, groundwater, rivers and lakes.

Water stored in rock and soil, about 30% of fresh water and a major source of drinking and irrigation supply.

When demand approaches or exceeds available supply; the UN marks stress below 1,700 cubic metres of renewable water per person a year.

Natural shortage caused by dry climates and few rivers, as in the Middle East and the Sahara.

Water exists, but poverty, pollution or poor infrastructure keeps people from safe supply.

Water replenished yearly by the water cycle — the measure of each region's supply potential.

A region's total water divided by its population — the more people, the less each has.

The direst level of shortage: under 500 cubic metres of renewable water per person a year.

Water for drinking, cooking, cleaning and city services — about 10% of global use.

Water for manufacturing, power generation and mining — about 20% of global use.

A river crossing two or more countries — over 260 worldwide, needing treaties to share.

The upper and lower reaches of a river; upstream dams change the flow, sediment and ecology downstream.

The huge dam Ethiopia began on the upper Nile in 2011 — Africa's largest power project, at the centre of years of dispute with Egypt and Sudan.

The international river from the Tibetan Plateau through six countries; upstream dams alter downstream flows and fisheries.

Southeast Asia's largest lake, fed by the Mekong's seasonal flood — the heart of Cambodia's fisheries.

When river flow drops, seawater pushes up the estuary, spoiling farmland and supplies.

An agreement dividing a shared river, such as the 1960 Indus Waters Treaty between India and Pakistan.

Removing salt from seawater (e.g. reverse osmosis); weather-proof but power-hungry and costly.

Pressing seawater through a membrane to leave salt behind — the method used at the Tseung Kwan O plant.

Fresh water piped to Hong Kong from Guangdong's Dongjiang since 1965 — now about 70 to 80 percent of supply.

Limiting when or how much water people may use; in the 1963 drought Hong Kong had four hours every four days.

Charging for water to reflect cost and scarcity and encourage saving; Hong Kong uses a tiered tariff.

Labels grading showers, taps and other fittings by water efficiency so buyers can choose savers.

Treated wastewater fit for reuse (irrigation, flushing); Singapore's NEWater is the famous example.

Singapore's supply strategy: local catchment, imported water, NEWater and desalination together.

Meters that log use in real time and detect leaks, helping users and utilities manage demand.

The process by which people concentrate in cities and the urban share of population keeps rising.

The percentage of a population living in urban areas — the main measure of urbanisation.

Movement of people from countryside to city — the main engine of urbanisation.

Negative factors driving people from the countryside: land shortage, low incomes, poor services, hazards.

Positive factors drawing people to cities: jobs, wages, schooling, health care and infrastructure.

Lower-income, less industrialised countries; late to urbanise but now urbanising fastest, e.g. in Africa and South Asia.

Early-industrialised, high-income countries with high urban shares (over 80%) but slow growth.

The Chinese city that grew from a border town into a metropolis of over ten million — the icon of China's urban boom.

People who leave farms to work in cities; China has nearly 300 million, powering manufacturing and construction.

A city of over ten million people; more than thirty exist, led by Tokyo's 37 million.

When vehicles exceed road capacity, costing time, fuel and money.

Fine particles under 2.5 micrometres that reach deep into lungs and blood — from traffic, factories and power plants.

Settlements lacking piped water, sewers and safety, often informal — as in Dhaka and Rio de Janeiro.

The self-built hillside slums of Brazil; over a million people live in Rio de Janeiro's.

Flats chopped into tiny rented cubicles; about 220,000 people live in them in Hong Kong.

When homes cannot keep up with population growth, raising prices and crowding.

The outward, unplanned spread of cities over farmland and open land, lengthening commutes.

High-capacity public transport such as metros and buses — the main cure for congestion and pollution.

A city balancing environment, economy and society — meeting today's needs without shortchanging the future.

Adding parks, trees, green roofs and living walls to cool the city and soak up carbon.

Singapore's greening policy since the 1960s; green cover now approaches half the island.

High-capacity rail and buses, far more energy-efficient per passenger than cars.

Hong Kong's model of funding railways with property income and growing new towns along the lines.

The quota licence Singaporeans must bid for before owning a car, capping vehicle numbers.

Government-built homes let or sold below market prices, like Hong Kong's PRH and Singapore's HDB flats.

Singapore's public housing by the Housing and Development Board, home to about 80% of the population.

Cities running hotter than their surroundings because concrete traps heat; greening and ventilation corridors ease it.

A planned, self-contained community beyond the urban core; about half of Hong Kong lives in new towns.

Creating land from the sea; Central and parts of Tseung Kwan O were reclaimed.

The 2018 plan to build reclaimed islands east of Lantau — over a thousand hectares at a cost in the hundreds of billions.

The 2021 plan integrating the northern New Territories into a metro area for population and innovation industry.

New Territories farmland spoiled or used for storage and recycling yards — developable, but clearing it means relocation.

Areas planned for new development, such as Kwu Tung North and Fanling North.

Statutorily protected countryside — about 40% of Hong Kong's land and a focus of development debates.

Government housing sold below market (Home Ownership Scheme) or let at low rents (public rental housing).

Planning that leads with rail — as when the Tseung Kwan O line transformed commuting in 2002.

The natural trapping of outgoing longwave heat by greenhouse gases that keeps Earth warm; without it the average would be about -18 degrees Celsius.

The human-made strengthening of the effect as gas concentrations rise — the direct cause of global warming.

CO2, methane and nitrous oxide, which absorb longwave radiation; methane traps about 28 times more heat than CO2 over a century.

Coal, oil and gas, formed from ancient organisms; burning them releases CO2.

The amount of CO2 in the air, measured in ppm (parts per million) — up from about 280 to over 420.

Large-scale clearing of forests, which releases stored carbon and removes trees that absorb CO2.

Systems that absorb and store CO2, such as forests, oceans and soils.

The greenhouse gas CH4, from paddies, cattle and landfills — a powerful heat-trapper.

The long-term rise in global average temperature — about 1.2 degrees Celsius since the Industrial Revolution.

The vast ice of Greenland and Antarctica; its loss is a main driver of sea-level rise.

The steady shrinkage of glaciers, seen worldwide in mountain ranges.

Rising seas from thermal expansion and meltwater — about 20 cm globally in the twentieth century.

The sea turning acidic as it absorbs CO2, hindering shells and corals.

Overheated seas make corals expel their algae and turn white; prolonged heat kills — as on the Great Barrier Reef.

Heatwaves, downpours and fierce typhoons growing more frequent and intense as the world warms.

A night staying at 28 degrees Celsius or above; Hong Kong's hot nights keep rising, endangering the elderly.

Warmer air holds more moisture, so downpours intensify — Hong Kong's September 2023 black rainstorm broke hourly records.

The Himalayan glaciers feeding Asia's great rivers; warming melts the store away.

The 2018 super typhoon that set wind records in Hong Kong, felling tens of thousands of trees and flooding low areas.

The 2015 climate treaty in which nearly 200 parties pledged to hold warming well below 2 degrees Celsius, striving for 1.5.

Each country's own emissions pledge, reviewed and raised every five years — the core mechanism of the Paris Agreement.

Balancing emitted and absorbed greenhouse gases for a net of zero; China targets before 2060, Hong Kong before 2050.

The turning point when emissions peak and start to fall; China pledges to peak before 2030.

Cutting emissions and adding sinks to attack the causes of climate change.

Adjusting infrastructure and lifestyles to impacts already unavoidable, such as higher seawalls.

Hong Kong's strategy of phasing out coal and moving to zero-carbon power with gas and renewables.

Buildings designed to save energy and water; they take about 90% of Hong Kong's electricity, making them central to cuts.

Hong Kong's roadmap: carbon neutrality before 2050, halving emissions by 2035 from 2005.