A laptop feels clean. Nothing burns, nothing smokes, and the cost of running it is invisible. The costs are real; they are just somewhere else — in a mine, in a data centre, in a landfill, and in your own shoulders after four hours of bad posture.
Where the harm actually is
- Making the device. Most of a phone’s or laptop’s lifetime carbon footprint is spent before it is switched on: mining the metals, refining them, assembling and shipping. This is why the greenest machine is almost always the one you already own.
- Running it. A laptop is modest; a desktop with a large graphics card is not; and the data centre answering your search is a building full of machines that also has to be cooled.
- Throwing it away. Electronic waste carries lead, mercury, and cadmium. In landfill those reach soil and water. Shipped abroad for informal “recycling”, they reach people.
- Health, at the desk. Eye strain, repetitive strain in wrists and thumbs, back and neck pain from a screen at the wrong height, sleep disrupted by late screens, and the mental-health effects of always being reachable.
What measurably helps
| Instead of | Do this | Why it matters |
|---|---|---|
| Replacing on a cycle | Repair, upgrade memory or storage, and keep it | Avoids the manufacturing footprint entirely |
| Binning the old one | Donate it working, or recycle it properly | Keeps metals in use and toxins out of ground |
| Leaving machines on | Sleep settings, and switch off overnight | Free, and immediate |
| Buying whatever is on sale | Check repairability and efficiency ratings first | Decides the next five years, not this week |
| Working through the ache | Screen at eye level, feet flat, break every half hour | The injuries are cumulative and slow to heal |
In Ontario, recycling is a solved problem administratively: electronics are accepted free at approved drop-off depots under a producer-responsibility program, and equipment that still works can be donated for refurbishment rather than shredded. Where to take it is on Where to Take It, and Who to Ask.
Computers as part of the solution
The same machines also make environmental work possible, and this is not a consolation prize — it is much of what computer science is currently for:
- Modelling climate, watersheds, and air quality, which is how policy gets evidence at all.
- Sensing: networks of cheap sensors reporting temperature, water level, or soil moisture continuously, where people once took monthly readings.
- Optimising: routing delivery trucks to cut kilometres, timing traffic lights to cut idling, scheduling industrial loads for when the grid is cleanest.
- Replacing travel where a video call genuinely serves — while being honest that the call is not free either.
- Precision agriculture: water and fertiliser where they are needed, rather than uniformly.
A program you write in this course could do a small version of any of these. That is the point of The Green Audit — measurement first, because a claim about impact without a number behind it is only a feeling.
Curriculum connection
D1.1
describe the negative effects of computer use on the environment (e.g., creation of e-waste, excessive use of paper resulting from unnecessary printing of files and emails, heavy power consumption) and on human health (e.g., exposure to radiation, musculoskeletal disorders, eye strain, mental health problems resulting from social isolation, various health consequences of reduced activity levels);
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D1.2
identify measures that help reduce the impact of computers on the environment (e.g., lab regulations, school policies, corporate and government policies promoting paperless workplaces and computer recycling and reuse) and on human health (e.g., ergonomic standards);
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D1.3
describe ways in which computers are or could be used to reduce resource use and to support environmental protection measures (e.g., computer modelling to reduce use of physical resources; management of natural resources);
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