Water Insecurity: A Global Crisis

This lesson examines the concept of water insecurity, including the distinction between physical and economic water scarcity, the global pattern of water stress, and the role of population growth, rising consumption, virtual water trade and hydropolitics. It addresses Edexcel A-Level Geography (9GE0) Paper 1, Topic 5, Enquiry Question 3: How does water insecurity occur and why is it becoming such a global issue?

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Defining Water Security and Insecurity

Water security is the reliable availability of an adequate quantity and quality of water for health, livelihoods, ecosystems and production, coupled with an acceptable level of water-related risk (UN-Water, 2013).

Water insecurity occurs when these conditions are not met — when people, communities or nations face inadequate, unreliable or unsafe water supplies.

The Scale of the Problem

Statistic	Data
People lacking safely managed drinking water	2.2 billion (2022, WHO/UNICEF)
People lacking safely managed sanitation	3.6 billion
Countries experiencing water stress	~60 (using >25% of renewable resources)
Deaths from unsafe water/sanitation/hygiene per year	~829,000
Global freshwater withdrawal (2020)	~4,000 km³/yr
Available renewable freshwater	~42,000 km³/yr
Projected people facing severe water scarcity by 2050	5+ billion (UN, 2023)

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Physical vs Economic Water Scarcity

A critical distinction in understanding water insecurity is between physical and economic scarcity.

	Physical Water Scarcity	Economic Water Scarcity
Definition	Insufficient water resources to meet demands (supply problem)	Water resources exist but cannot be accessed due to lack of infrastructure, investment or governance (access problem)
Cause	Arid climate, limited rainfall, depleted aquifers, high demand relative to supply	Poverty, under-investment in infrastructure, poor governance, conflict
Regions	Middle East, North Africa, Central Asia, parts of South Asia, Australia, western US	Sub-Saharan Africa, parts of Southeast Asia, some Pacific islands
Example	Saudi Arabia: annual rainfall <100 mm; natural renewable water resources are almost zero; depends on desalination (75% of supply)	Democratic Republic of Congo: abundant water resources (the Congo River has the 2nd highest discharge in the world at ~41,000 m³/s) but only 26% of population has access to safe water
Solution approach	Demand management, desalination, water recycling, inter-basin transfers	Investment in infrastructure, improved governance, community-based management

Exam Tip: Always specify whether water scarcity is physical (not enough water) or economic (water exists but is inaccessible). Many exam answers lose marks by treating water insecurity as only a supply problem. Sub-Saharan Africa typically has economic scarcity — the water exists but infrastructure and governance are lacking.

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Water Stress: Definitions and Thresholds

The most widely used measure of water stress is the Falkenmark indicator, based on renewable freshwater per capita:

Category	Freshwater per capita (m³/yr)	Condition
No stress	>1,700	Adequate for all needs
Water stress	1,000–1,700	Occasional water shortages
Water scarcity	500–1,000	Chronic water shortages; affects food production
Absolute water scarcity	<500	Severe scarcity; basic needs not met; health and livelihood impacts

Current and Projected Water Stress by Region

Region	Current (m³/capita/yr)	Projected 2050	Trend
Middle East & North Africa	~500	<250	Worsening rapidly
South Asia	~1,200	<800	Approaching scarcity
Sub-Saharan Africa	~4,000	~2,500	Declining due to population growth
East Asia	~2,000	~1,500	Declining
Europe	~4,500	~4,000	Stable overall but regional variation
North America	~6,000	~5,000	Generally adequate but hotspots (SW US)
UK	~2,300	~1,800	Southeast England already stressed

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Drivers of Water Insecurity

1. Population Growth

• Global population has grown from 2.5 billion (1950) to 8.0 billion (2023) and is projected to reach 9.7 billion by 2050
• Total global water demand has increased 6× over the past century
• The highest population growth rates are in regions already facing water stress (sub-Saharan Africa, South Asia)
• More people = more demand for drinking water, food production (irrigation), industry and energy

2. Rising Consumption

Per-capita water use increases with economic development:

Country	Daily per-capita water use (litres)	Income Level
USA	~380	High
UK	~143	High
China	~90	Upper-middle
India	~55	Lower-middle
Ethiopia	~15	Low

As LICs develop, per-capita consumption increases. If global per-capita consumption reached US levels, total demand would nearly triple.

3. Sectoral Water Use

Sector	% of Global Freshwater Withdrawal	Key Details
Agriculture	70%	Irrigation is the dominant use; rice paddy, cotton and sugarcane are the most water-intensive crops
Industry	19%	Cooling water for power generation, manufacturing, mining
Domestic	11%	Drinking, washing, sanitation