Even if you’re an optimist, Earth is currently on track for an uncertain fate. The UN Intergovernmental Panel on Climate Change (IPCC) has concluded that global greenhouse gasses (GHG) need to be cut by 45 percent by 2030 and 100 percent by 2050 in order to avoid “catastrophic warming” of 2°C above preindustrial levels. Many scientists believe that even the UN’s report isn’t radical enough, arguing that the planet’s so-called “carbon budget” is already spent and that 2°C of warming is already locked-in.

While the IPCC report suggests that a rapid rollout of renewable energy technologies and some largely untested and even undeveloped carbon capture technologies could resolve the climate emergency, such a solution doesn’t address the findings of another UN body. According to the UN Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, over one million species of life are at risk of extinction, threatening the entire biological web on which we and the planet with which we are interconnected depend.

To address these issues and more, an emerging movement is calling for controlled economic “degrowth”, that is a justice-oriented shrinking of industrial output and consumption. This project would be unlike the austerity measures put in place by national governments in the wake of the 2008 recession, which mostly targeted social welfare programs. Instead, degrowth advocates argue for a restructuring of industrial society away from an economic paradigm dependent on increased annual GDPs and toward one “that increases human well-being and enhances ecological conditions and equity on the planet.” It’s worth noting that many degrowth advocates suggest that, once industrial society is brought within ecological limits, it may be able to maintain a steady-state economy, so that further degrowth is no longer necessary.

A demonstration at the end of the Fourth International Conference on Degrowth in Leipzig, Germany in 2014. Image courtesy of Creative Commons/http://leipzig.degrowth.org

Like any movement, the degrowth movement is a diverse one with members sometimes at odds with one another, many definitions of degrowth, and countless strategies for how to achieve them. There are numerous conversations being had and projects being implemented related to social justice and reorganizing society, but technology is less frequently discussed mostly due to the fact that technological development often stands in direct contrast to sustainable degrowth.

While bringing industrial society into ecologically sustainable limits most likely requires de-emphasizing technological means of human fulfillment, it does not preclude the use of technology and, among the tech that could feasibly fit into a degrowth community is 3D printing. Here, we’d like to take a look at whether or not and how additive manufacturing (AM) might be featured in a degrowth society.

The Sustainable Side of 3D Printing

Less Material Waste

Those in the 3D printing community are likely well aware of the potentially sustainable aspects of the technology. The most obvious is the fact that parts are built up layer by layer, rather than made from milling away material from a solid block, as is the case with CNC machining and other subtractive manufacturing. And, unlike injection molding and casting, there’s no need for indirect manufacturing tools, like molds and dies. Ideally, all that’s needed is a printer and feedstock, so there’s overall less material waste than other processes.

Fewer Shipping Emissions

If production-capable 3D printers were equitably dispersed worldwide, it could even be possible to achieve the goal of many in the AM industry: on-demand distributed manufacturing. As it stands, manufacturing is made up of a fragmented supply chain in which centralized production facilities make the parts and have them sent to another facility where end products are assembled before they are shipped to warehouses and then ultimately sent to brick-and-mortar shops for purchase or sent to the customer after being purchased online.

A 2015 EU study determined that aviation and maritime shipping are responsible for 3 to 4 percent of GHG emissions. By 2050, it is projected that this sector could make up 17 percent of GHG emissions, if we remain on our current course. This doesn’t include ground transportation. According to the Air and Waste Management Association, heavy-duty truck, rail and water transport represented 25 percent of CO₂ emissions in the United States and 30 percent in Europe in 2007.

The concept of on-demand distributed manufacturing inverts this paradigm such that 3D printers produce parts nearest to their point of use. Consumers could simply download a file for something they need and have it made at a local hub, such as a library or post office. Not only would this eliminate the shipping associated with sending parts all over the planet, but it would also do away with the idea of inventory, which is taking up valuable space that could be used (in a degrowth society) for rewilding and natural carbon capture.

Closed-Loop Production

Playing a huge role in the overall destruction of life on earth is the huge amounts of waste generated by industrial nations. In 2012, the World Bank estimated that humans produce about 2.6 trillion pounds of garbage annually, with 46 percent generated by high-income countries like the U.S. and U.K. Post-consumer waste is responsible for about 5 percent of global GHG emissions, as well.

All of this is a result of both a growth-oriented production and consumption model, as well as poorly implemented waste management programs. Whereas the U.S. has only seven different codes for categorizing plastics, China has 140.

Through his Open Sustainability Technology (MOST) group, Michigan Tech professor Joshua Pearce has performed extensive research into how to make 3D printing itself more sustainable, but also how to integrate the technology into a closed-loop production system. Work related to the former mostly involves incorporating new recycling symbols onto 3D printed parts so that they may be processed in current or future recycling plants. The latter involves such systems as MOST’s RecycleBot, which converts plastic waste into 3D printable filament.

The recycling process for converting plastic milk jugs into 3D-printable filament. (Image courtesy of Michigan Tech’s Open Sustainability Technology lab.)

This will be a key component to a distributed manufacturing ecosystem, as 3D printer owners will be able to recycle previously printed goods based on these codes. To make this possible, Pearce’s group also developed the RecycleBot, a device capable of converting plastic waste into 3D-printable filament.

With such technology as the RecycleBot, it would be possible to distribute recycling in the same way that production could be distributed using 3D printing. Individual consumers or local hubs could perform their own recycling operations, which, according to Pearce, is better for the environment than our current recycling model.

Ultimately, it could be possible to establish what Pearce refers to as “industrial symbiosis,” in which the waste byproducts of one production facility would become the material feedstock for another. In a study detailing the possibilities of an eco-industrial park dedicated to solar panel manufacturing, Pearce determined that it could be possible to reduce raw material use by 30,000 tons per year and embodied energy use by 220,000 GJ per year. (You won’t be surprised to know that Pearce’s group has also done extensive research into distributed renewable energy generation, as well.)

An eco-industrial park centered on a photovoltaic manufacturing plant. Image courtesy of Renewable Energy.

There are likely other sustainable features of AM that we’ve left out, but here we’ve outlined some of the technology’s most ecologically friendly features, as well as the ways that 3D printing could ideally be used to reduce the ecological footprint of an industrial society under degrowth. In the next part in our series, we will look more closely at the reality of AM and just how sustainable it really is.