“Go paperless, save trees”. Is that really the case? According to this popular motto, documents in digital versions are environmentally sounder than their old-school, paper counterparts. It may be easy to think so since we’re quite aware of the link between a tree and our notebook. Yet the largely hidden life cycle of electronic devices, from production through powering to disposal, adds up to their environmental impact. Accounting for the supply chain of electronic appliances may well disqualify digital as the ‘greener alternative’. Besides, the paper has the potential to contribute to carbon-storing while the digital is limited in this regard.

The comparison is context-dependent in a twofold way. The producer’s environmental choices can have a great impact on the sustainability of the final product, either paper or digital. Besides, the variations in the environmental footprint mean that you can assess what’s more environmentally friendly in a particular situation. We hope that this article will give you a starting point for critically evaluating both options. We will be comparing the environmental footprint of a 20-page article, printed on a standard office printer or displayed on a 17-inch screen laptop.

Bio-based versus toxins: the production process
Let’s start backstage. What does it take to produce a paper and a digital article? The brainpower of the author aside: how did this article end up on your desk?

If you’re reading the paper version of our imaginary document, the white pages in front of you were likely a living part of a forest not so long ago. It takes over 8 trees to produce 100,000 sheets of paper, generating a carbon footprint of 6,000 kg of CO2 equivalents. Our 20-page article is likely to have a carbon footprint of 1.2 kg, coming only from the energy used to produce the pages. The act of printing has a negligible energy impact (order of magnitude <0,001 kg-CO?eq. / page).

The production of 20 sheets of paper takes up 6.4 L of freshwater, which adds an extra 0.65 kg of carbon footprint to the 1.2kg value from energy use in production. Since energy and water footprints together form the bulk of the product’s carbon footprint, we can make a ballpark estimation for our paper article’s total carbon footprint. Producing and printing the 20-page document has a carbon footprint of approximately 1.85 kg.

Freshwater used in paper production makes a strong case for the need for recycling. Image source
While the energy from the act of printing is negligible, the carbon footprint of producing the printer isn’t. The data on the energy and water use to produce a single printer is extremely scarce, yet an environmental report of a large printer producer shows their overall environmental impact for 2019 at 46,785,800 t of carbon dioxide. This value includes the production of printers (material extraction, capital goods, energy production, and transportation), facilities, and product use. The production-to-use carbon footprint ratio is 50 to 49, which means that we need to count the negligible singular energy impact of printing the 20-page document as double.

If you went for the digital version of our article, we first need to account for the appliance that allows you to read online: your imaginary 17-inch screen laptop. Manufacturing one laptop causes the carbon dioxide emissions of between 227 to 270 kg from energy use. The energy used in the process constitutes 70% of the energy consumption of the whole lifespan of the device. Accounting for the water usage—a conservative estimate of 6,500 liters per laptop—adds an extra 655.2 kg of CO2 emissions. In total, producing a laptop creates a carbon footprint of between 882.2 kg and 925.2 kg.

Considering the average lifespan of a laptop at four years put the annual carbon footprint of a laptop owner at between 220.6–231.3 kg. If we assume that you use your laptop for 6 hours a day, 5 days a week (1,350 hours yearly for 45 working weeks), your laptop’s carbon footprint embedded in production equals approximately 0.25 kg of carbon dioxide per hour. Assuming that it takes between 64 and 80 minutes to read a 20-page article, the carbon footprint for reading equals 0.27–0.3kg.

Most of the emissions come from extracting the necessary materials, and carbon footprint is not the only environmental issue here. Any laptop—and electronic device in general—contains rare earth metals as well as toxic substances. The current status quo of extracting minerals and chemicals is harmful to both the environment and the workers. Laptops contain lead in their batteries, and some LCD screens contain mercury. Many of these chemicals end up in the environment already during production, and especially once they’re disposed of.

The majority of global laptop production is located in China. With its lax environmental regulations and low accountability for workers’ rights, China produces quickly and cheaply, with a massive drain on socio-environmental sustainability. Unless you own a new laptop from a hyper-conscious, ethical brand (or a second-hand one), with the appropriate certification, there is a fair chance that your laptop was part of the chain of social and environmental abuse.

Footprint per hour: the implications of the use
For laptops, the carbon footprint increases proportionally to the time that you spent on reading. Paper copy emissions originate only from the time the document was printed and remain stable until their recycling.

A 17-inch laptop screen has a carbon footprint of approximately 23.4 g per hour of reading. Therefore, assuming the reading time is between 64 and 80 minutes, the emissions from the reading would equal 25–31g. The energy consumption varies greatly among electronic devices: it is lowest for single-purpose reading devices such as Kindle and increases steadily through tablets and laptops to reach the highest in computer screens and desktops.

Single-purpose reading devices have the lowest environmental impact among electronic devices. Image source
The carbon footprint of the digital paper doesn’t end here. If you accessed the article online, your online pursuit activated several data centers. Websites are stored in data centers, too, so accessing a server consumes energy needed for running and cooling them. Admittedly, your single 20-page article won’t consume much—transferring 1GB of data takes approximately 5 kWh. Therefore, the emissions of a 1 GB transfer reach between 2 and 3 kg of carbon dioxide, depending on the energy efficiency of a power plant.

A 20-page document without images won’t surpass a couple of hundreds of kilobytes, so its emissions could be negligible. The size of a 20-page article can vary between 150–1250 kB, depending on the number of images, and the corresponding carbon footprint amounts to between 0.00034–0.0028 kg. Since this figure is relevant each time you open such an online document, you can prevent the increase of your carbon footprint by downloading the article you will need to read multiple times.

Yet, several billions of users all with a ‘negligible impact’ add to about 2% of global electricity use that the data centers currently take up. At this point, data centers contribute to 0.3% of global carbon emissions. Predictions show an increase in energy use to 8% of the global total in 2030.

Afterlife, only overseas
How your product ends its life has an important effect on its overall environmental footprint. The effort you put into bringing your papers and laptops to a recycling point, repurposing them, or selling your laptop second hand, will have a tangible impact.

A sheet of paper can be recycled up to seven times. Recycling paper to its maximum capacity can drop its carbon emissions by 47%, from 6,000 kg per 100,000 sheets to 3,200. Europe recycles over 70% of its paper, and the figures are comparable worldwide. Making sure that your 20-page document is recycled to its maximum would reduce its carbon footprint from 1.85 kg to 0.87 kg. This value includes saving 2.65 L of freshwater.

The only emissions from deleting your digital file come from the energy used to power your screen. Yet what will happen with your laptop once you choose to get a new one has an impact significant enough to mention it for this case.

As you may remember, the greatest part of the carbon footprint from laptop production comes from extracting metals. Recycling a laptop means offsetting 50% of emissions that come into the production of a brand new laptop. The value reaches 75% for second-hand laptops. Yet in 2019, only 17% of the 54 million tons of e-waste was recycled, which puts the overall value at 9% for a new laptop from recycled parts and 14% for a second-hand one. Putting the effort in to sell your laptop second-hand, or to bring it to a genuine recycling point (which will require some research) significantly decreases your carbon footprint.

https://www.sciencedirect.com/science/article/pii/S1876610217309554science direct

The amount of electronic waste rises three times faster than the world’s population, and 90% of it is dumped illegally. In 2019, we humans generated 54 million tons of e-waste: an equivalent to 7.3kg for every inhabitant of the planet. Alongside valuable metals inside of the electronic devices, there are some highly toxic ones. Often, it is the job of children and women in developing countries that host the piles of e-waste to retrieve valuable metals. This process of semi-recycling often turns out more harmful for both the retrievers and the environment, for example when the workers burn the laptops to retrieve copper.

The hidden potential of paper
While the ability to lower the carbon footprint of a laptop stagnates when we achieve 100% recycling, the paper has the potential to contribute to improving the overall carbon sheet by delaying emissions. Transforming trees into paper means temporarily storing the carbon that will be released into the atmosphere upon burning. A study in a Chinese mill paper showed that accounting for the carbon storage abilities of paper in a Life Cycle Assessment (LCA) shows the reduction in emissions by 24% over 30 years.

Combined with the paper industry’s ability to increase natural capital by replanting trees, the carbon storage capacity presents the industry with an opportunity to become climate positive.

‘It depends’? Some advice to counter relativity
The simple answer to the ‘digital vs. paper’ dilemma is: if you only scan through documents, it is more sustainable to read them online. If you will read it more than three times or you plan to pass it over to another reader, printing is the better option. The table below summarizes this finding.

Since the environmental footprint is context-dependent, try to account for your context before deciding on digital or paper. For example, if you host a meeting during which you will present some documents, think about how many people attend to understand how many paper copies you will have to print and contrast this with the amount of time you will keep a projector running. You can find the carbon estimates for such a scenario under ‘Sources & additional resources’.

Several rules of thumb apply to minimize your environmental footprint, no matter whether you go for digital or paper.

Try to maximize the lifespan of your laptop or your printed materials.
Circulate paper copies so that they serve more than one person.
Consider selling or donating your old device once you bought a new one.
Remember to make sure that your waste?—?either electronic or paper?—?is properly recycled.
Go for laptops rather than desktop computers due to their energy consumption, and opt for smaller screens.
Try to read offline and turn your device off when you don’t use it.
Researching sustainable paper plants can further decrease your environmental footprint.
Besides the multitude of contexts, the greatest difficulty for a systemic analysis of the environmental impact of digital versus paper copies is the lack of data available on the electronic appliances’ producers’ side. Cross-industry reporting standards on sustainable footprints would be a quintessential step, boosting transparency and allowing questions like these to be openly validated and answered.

Our analysis accounted only for the carbon emissions, not taking into consideration other sustainable boundaries such as environmental toxicity basis or macro-rare-resource use basis. We mention the boundaries in italics, hoping to further stimulate your interest.

découvert par article https://www.nicematin.com/environnement/pollution-de-la-mer-francoise-loques-sentinelle-chevronnee-de-la-mediterranee-menacee-913700 sur Françoise Loquès