CAIE 9618 · Paper 1 · Topic 1.6.3

Environmental Impacts
of Computing

Energy Use · E-waste · Carbon Footprint · Cloud Impact · Sustainable IT

CSZone Cambridge International AS & A Level Computer Science 9618

Energy Consumption

How Much Power Does Computing Use?

The global ICT (Information and Communications Technology) sector accounts for approximately 3–4% of worldwide electricity consumption — comparable to the aviation industry.

DATA CENTRES

Run 24/7, requiring vast cooling systems. Large data centres consume as much electricity as small towns. Training a single large AI model can emit as much CO₂ as five cars over their lifetime.

USER DEVICES

Billions of smartphones, laptops, and PCs draw continuous power. Always-on devices (smart home, IoT sensors) add significant "idle" consumption globally.

Electronic Waste (E-waste)

The Growing Waste Problem

E-waste is discarded electronic equipment. It is the fastest-growing waste stream globally, reaching ~60 million tonnes per year.

Toxic materials — electronics contain lead, mercury, cadmium, and brominated flame retardants. Improper disposal leaches these into soil and groundwater.

Short product lifecycles — planned obsolescence and rapid product cycles mean devices are discarded while still functional.

Export to developing nations — e-waste is often shipped to countries with looser regulations, causing severe local health impacts.

Recycling — devices contain valuable metals (gold, copper, lithium). Responsible recycling recovers these and reduces mining demand.

Extended Producer Responsibility (EPR) — legislation requiring manufacturers to fund recycling of their products.

Reducing Environmental Impact

Sustainable Computing Practices

RENEWABLE ENERGY

Data centres powered by solar, wind, or hydroelectric. Google, Microsoft, and Apple have committed to 100% renewable energy for their data centres.

ENERGY-EFFICIENT HARDWARE

ARM-based processors (RISC) consume significantly less power than x86. Low-power modes, efficient power supplies, and solid-state storage reduce consumption.

VIRTUALISATION & CLOUD

Running many virtual machines on fewer physical servers improves utilisation. Reduces number of idle physical machines needed overall.

GREEN SOFTWARE DESIGN

Writing efficient algorithms reduces processing time and energy. Avoiding unnecessary network requests and optimising data transfers reduces infrastructure load.

Exam Practice

Cambridge-style questions

Question 1

Describe two negative environmental impacts of the increasing use of cloud computing and data centres. For each, suggest one way organisations can reduce this impact.

8 marks

2+2

Impact 1: High energy consumption — data centres run 24/7 and require cooling systems, producing significant CO₂ emissions. Reduction: power data centres using renewable energy sources such as solar or wind power.

2+2

Impact 2: Increased e-waste — frequent hardware refresh cycles in data centres generate electronic waste containing toxic substances. Reduction: implement extended use policies, donate decommissioned equipment, or use specialist e-waste recycling programmes to recover valuable materials.

Common Mistakes

Don't lose easy marks

Saying cloud computing is always "green" — cloud shifts the environmental impact away from the user's device, but the data centre still consumes large amounts of energy. Whether the cloud is "greener" depends on whether it uses renewable energy and how efficient the servers are.

Vague answers like "computers use electricity" — you must be specific about the context: data centres, cooling systems, manufacturing, transport, or end-of-life disposal. Name the specific impact and quantify where possible.

Forgetting about the manufacturing phase — most of a device's lifetime carbon footprint comes from manufacturing (mining raw materials, factory energy use, transport), not just its operational electricity use.

Topic Summary — 1.6.3

What You Need to Know

ENERGY CONSUMPTION

ICT ≈ 3–4% global electricity
Data centres: 24/7, heavy cooling
AI training: massive energy footprint

E-WASTE

~60M tonnes/year worldwide
Toxic: lead, mercury, cadmium
Export to developing nations is common

SOLUTIONS

Renewable energy for data centres
Energy-efficient RISC processors
Virtualisation, green software design
Responsible recycling (EPR laws)

KEY PRINCIPLE

Environmental impact spans full lifecycle:
Manufacturing → Operation → Disposal
Cloud computing ≠ automatically green

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