The carbon cost: are laptops climate friendly?
The global IT industry produces 272 million laptops every year, with each laptop’s production responsible for an average of 331 kg of CO2. UK daily per capita emissions are about 30 kg per day, so this is about 11 days of your carbon footprint, equivalent to a flight from London to Rome. Emissions are produced at every stage of a laptop’s lifecycle: resource extraction, multiple stages of manufacture, transportation, usage and disposal.
Thinking more broadly, the overall carbon impact of the IT sector is difficult to quantify (partly due to the industry keeping relevant data secret) and estimates sometimes differ by orders of magnitude. It accounts for up to 2.5% of global emissions, but do the efficiency savings that IT makes possible reduce the world's carbon footprint overall?
The sheer complexity and centrality of IT to the modern world makes it hard to say, but Jevon’s paradox or ‘rebound effect’ provides an interesting thought experiment. The paradox occurs when technological progress improves the efficiency with which a resource is used, but the reduced cost of use increases its demand, negating any reduction in resource use.
IT gains have enabled massive energy efficiency improvements across countless industries, but this has then allowed for massive usage increases. Technological progress makes data cheaper, communication faster, and hardware more powerful. People and businesses then consume more data and communicate more, and the industry invents increasingly complex products and services, mitigated by the efficiency gain. Therefore, controlling demand will be crucial if humanity wishes to take advantage of IT’s carbon-saving potential.
For individual consumers, the key takeaway is to purchase less and to get as many years of life from each product as you can.
The manufacturing stage is by far the most resource intensive element of a laptop’s lifecycle. More powerful, higher-quality laptops may have a slightly higher manufacturing footprint, but this is often negated by their longer lifetimes. Buying refurbished or second hand will always be the lowest-carbon option, and make sure to ask about repairability when choosing a model.
The carbon footprint from a year's use of a mid-range MacBook Pro, assuming it lasts 4 years with an average use of 3hrs/day, has been calculated as: 83% carbon embodied in the laptop, 15% network and data centres, 2% electricity use (data from Mike Berners-Lee's book, How bad are Bananas?)