The wooden skyscrapers that could help to cool the planet
Large timber buildings are getting safer, stronger and taller. They may also offer a way to slow down global warming.
One building stands out in the old logging town of Prince George, Canada. Encased in a sleek glass facade, the structure towers above most of its neighbours, beckoning from afar with the warm amber glow of Douglas fir. Constructed almost entirely from timber in 2014, the 8-storey, 30-metre building is among the tallest modern wooden structures in the world. But it is more than an architectural marvel. As the home of the Wood Innovation and Design Centre at the University of Northern British Columbia (UNBC), it is also an incubator for wooden buildings of the future — and a herald for a movement that could help to tackle global warming.
The building, which is owned by the government of British Columbia, is less like a log cabin and more like a layered cake, constructed from wooden planks glued and pressed together, precision cut by factory lasers and then assembled on site. All told, the university avoided the release of more than 400 tonnes of carbon dioxide by eschewing energy-intensive concrete and steel, and the building locks up a further 1,100 tonnes of CO2 that was harvested from the atmosphere by British Columbian trees. In total, that's enough to offset the emissions from 160 households for a year.
Wooden construction has ancient roots, but only in the past two decades have scientists, engineers and architects begun to recognize its potential to stave off global warming. By substituting concrete and steel with wood from sustainably managed forests, the building industry could curb up to 31% of global carbon emissions, according to research1 by Chad Oliver, a forest ecologist at Yale University in New Haven, Connecticut. In time, such a shift could help humanity to pull CO2 out of the atmosphere, potentially reversing the course of climate change.
“It's the plywood miracle,” says Christopher Schwalm, an ecologist at Woods Hole Research Center in Falmouth, Massachusetts. “This is something that could have a significant impact on the riddle that is global environmental change.”
The renaissance in tall wooden buildings is already under way. Norway set a world height record in late 2015 with a 52.8-metre tower block; that was edged out in September 2016 by a 53-metre student dormitory at the University of British Columbia in Vancouver. This year, Austria will take the lead with the 84-metre HoHo building in Vienna, comprising a hotel, apartments and offices. The United States saw its first tall wooden building go up in Minneapolis, Minnesota, in 2016, and others are in the works in Portland, Oregon, and in New York City.
Wooden construction has attracted political interest in part because of the economic benefits for rural communities surrounded by forests. But turning these pioneering projects into a global trend won't be easy. Building costs are often high, and the global construction industry is almost entirely focused on concrete and steel, particularly when it comes to big buildings. And the climate benefits of building with wood hinge on a questionable assumption: that the world's forests will be managed sustainably. Some researchers worry that harvesting more timber could harm forest ecosystems, particularly in developing countries that are already plagued by poor and often illegal logging practices. “If we're going to cut wood, we've got to do it in a way that not only sustains the forest but also sustains the biodiversity and everything else,” says Oliver.
Steel and concrete weren't an option when Buddhist monks set about building a 32-metre pagoda at the Learning Temple of the Flourishing Law in Ikaruga, Japan, 14 centuries ago. They put their faith in wood, as did the monks at the Sakyamuni Pagoda in Yingxian, China. Erected in 1056, that structure rises a staggering 67 metres towards the heavens.
These pagodas are still standing today, a testament to the strength and durability of wood. Kilogram for kilogram, wood is stronger than both steel and concrete, and wooden buildings are generally good at withstanding earthquakes. But wood has developed a bad reputation over the centuries, because of catastrophic blazes that levelled cities such as London, New York and Chicago before modern fire-suppression strategies emerged. In fact, in case of fire wood maintains its structurally integrity much better than the non-flammable alternatives favoured by modern building codes. It chars at a predictable rate, and doesn't melt like steel or weaken like concrete. “The fact that it actually can withstand fire better than steel took a long time for people to realize,” says Guido Wimmers, who chairs a master's programme in wood engineering at UNBC.
By some accounts, the modern era of tall wooden buildings began 20 years ago, with a simple experiment at the Technical University of Graz in Austria. Researchers glued layers of standard planks perpendicular to each other, and discovered that alternating the direction of the grain effectively negated the imperfections and weaknesses in any given plank. The result, known as cross-laminated timber, is a strong and lightweight wood panel that puts conventional plywood to shame. It can be made as large as desired and cut with sub-millimetre precision at the factory, which speeds up construction and reduces waste. And given the strength of these panels, there's no theoretical limit to how high wooden buildings can grow. “It transforms wood from a suburban material to a very urban material,” says Michael Green, the Vancouver-based architect behind the design centre in Prince George, and a leading advocate for wooden construction.
Wimmers says the initial goal of the technology was to make better use of low-grade wood products. “The wood construction industry was slowly vanishing, so they started to reinvent themselves,” he says. Then the market for advanced timber technologies — including beams that are either glued or nailed together to increase strength — expanded as European countries put strict regulations on energy efficiency and greenhouse-gas emissions, forcing architects to reduce the climate footprints of their buildings. Wimmers estimates that in Europe, wood is now used in about 25% of residential construction, up from 5–10% in the 1990s.
The science of safety and engineering has also advanced. Douglas fir — the exposed layer at the design centre — chars at 39 millimetres per hour. The provincial building code requires that the structure be able to endure at least one hour of fire on any given storey, so Green's team opted for floors made of a 5-layer panel that could afford to sacrifice a portion without losing its structural integrity.
Meanwhile, Wimmers's team is collaborating on the Tall Wood Project, funded by the US National Science Foundation, to improve earthquake resistance for high wooden buildings. Work by the consortium has shown that the buildings can withstand earthquakes as well as or better than concrete and steel2, and the researchers will begin testing a two-storey wooden structure on a quake-simulator table at the University of California, San Diego, in June. They aim to test a ten-storey building there by 2020.
Asif Iqbal, a civil engineer who is working on the project, came to UNBC from New Zealand, where he saw the damage from the 2011 earthquake in Christchurch at first hand. Most of the steel-reinforced concrete buildings in the city remained standing, but around 1,800 were irreparably damaged owing to cracked concrete and warped steel. Iqbal says that many of the replacement buildings are being constructed from wood, precisely because it is more likely to survive another major earthquake and the steel connectors can be replaced relatively easily if damaged.
The long-term performance and economic viability of these buildings remains an open question. Wood is susceptible to mould and water damage, for example, and there is a higher risk of fire during construction. In September 2014, a £20-million (US$26-million) wooden sustainable-chemistry building being built at the University of Nottingham, UK, was destroyed by an electrical fire — in part because fire doors and windows were not yet in place to contain the blaze. Still, advocates say the future looks bright. “We are still fine-tuning wood technologies, but so far we haven't found any major issues that we cannot solve,” Iqbal says.
One of the main attractions of wooden construction is its potential to help stave off global warming. Oliver's research1 suggests that humans currently harvest only 20% or so of the global forest growth each year, and more timber could be extracted without reducing the overall amount of carbon locked up in forests. The eventual climate impact of this harvest depends on the end use.
If the wood were simply burned for energy, the CO2 that the tree had absorbed years earlier would immediately return to the atmosphere. Regrowing forests eventually pull that CO2 back out of the air, so the idea of carbon-neutral wood energy is a function of time. It is also controversial: some argue that current policies in Europe overstate the climate benefits of wood fuel and create perverse incentives to cut down trees. But this debate doesn't apply to wooden buildings. “Just the fact that you have solid wood means that you are keeping CO2 out of the atmosphere,” says Oliver.
Aside from the carbon sequestered in the wood itself, wooden construction offers further emissions savings. When researchers tallied the environmental impact of the design centre, they accounted for the manufacture and transport of every material — right down to the fossil-fuel-derived glue that binds the plywood together. Overall, the emissions related to construction were 12% of those for an equivalent concrete building3, largely owing to differences in fossil-fuel use. “When you compare a wood building with a concrete building, wood wins every time,” says Jim Bowyer, an emeritus engineer at the University of Minnesota in St Paul.
The design centre might have a uniquely low carbon footprint at the outset, but over time its environmental impact will grow as its heating, cooling and lighting requirements generate greenhouse-gas emissions. Day-to-day energy use and maintenance account for 80–90% of lifetime emissions for a typical building, and unfortunately the design centre is no different. The consequence is that its long-term climate benefits are relatively modest.
But the most advanced buildings today, which combine energy-efficient designs and technologies with on-site renewable energy generation, can eliminate emissions over the life of the structure. In such scenarios, construction and materials — the building's 'embodied emissions' — account for 100% of a building's climate impact, giving wood an increasingly important advantage.
“We're moving towards really low-energy buildings,” says Jennifer O'Connor, president of the Athena Sustainable Materials Institute, a non-profit research organization in Ottawa. “Quite frankly, if we are going to make a difference, then we had better start looking at those embodied emissions.”
The long game
The wooden-building movement is, for now, focused mostly on Europe and North America. In the United States, more than 80% of houses are already wood-based, says Bowyer. Yet with the nation's timber industry currently extracting roughly one-third of annual forest growth, there is capacity to expand wood construction in mid-rise commercial and industrial structures without reducing the volume of carbon that is locked up in forests. Bowyer is leading an expert assessment convened by the American Wood Council, an industry body in Leesburg, Virginia; the team has found that the United States could roughly double the amount of carbon that it sequesters in buildings each year, offsetting the emissions from nine additional coal-fired power plants. By contrast, builders in Europe still rely mostly on concrete and steel: a 2010 Finnish government report4 estimated that a mere 4% increase in annual wood use in construction throughout Europe would avoid 150 million tonnes of carbon emissions, almost as much as the Netherlands emits each year.
“This could have a significant impact on the riddle that is global environmental change.”
But to have a truly global impact, the movement must expand to developing countries, where forest management remains a challenge. Forests across the tropics are already being pillaged for timber and razed for agriculture. Indonesia, for example, has struggled to halt the palm-oil industry's destruction of rainforests. And although Brazil has made huge improvements in forest management over the past decade, demand for beef and soya beans is once again boosting land-clearing in the Amazon. Some fear that wooden construction would mean more trouble for some of the world's most precious ecosystems. “I've seen enough abuses of what you would call the wood-product sector that I'm leery of sweeping solutions that make big assumptions,” says William Laurance, a tropical ecologist at James Cook University in Cairns, Australia.
Oliver argues that the push for wooden construction could help developing countries to establish sustainable industries that actually protect forests, if they are pursued in parallel with efforts to bolster governance. The challenge is to ensure that managed forests maintain the full suite of crucial ecosystems, including old-growth habitat and forest clearings. “It should all be preplanned and transparent,” says Oliver. “That's kind of a utopia, but you've got to dream.”
He is working with the United Nations Development Programme (UNDP) to design a comprehensive forest-management plan that would kick-start modern wooden construction in Turkey. Government figures indicate that the country erected 956 million square metres of building space between 2004 and 2014, and just 0.13% of that total was framed in wood. Yet 27% of the country is forested, and 7 million of Turkey's poorest citizens live in these areas, says Nuri Özbağdatlı, a forestry expert with the UNDP in Ankara. “We want to create a new value chain for wood,” he says. “It will start with the forest villages and end up with the construction sector.”
As wooden construction matures, it will face one final challenge: what happens when a building is decommissioned and torn down. Buddhist pagodas may last for centuries, but the general assumption for many modern buildings — including the design centre in Prince George — is that they will outlive their usefulness and be replaced in several decades. If the wood is dumped into landfill and left to rot, its carbon will slowly leak back into the atmosphere. But if the wood is recycled — reused in future construction projects, for example — then the climate benefits are locked in.
Advocates of wood are pushing long-term strategies that promote recycling and other carbon-neutral options, but Green isn't too worried about the longevity of his building. Properly maintained, he says, there's no reason why it can't last as long as a Buddhist pagoda. Instead, he's focusing on getting this budding industry off the ground through a free online training course that will be translated into 30 languages, giving anybody with an interest — from architects and engineers to builders, developers and government officials — a more technical understanding of wooden construction. “We need to globalize the conversation,” Green says. “This is the only hope of accelerating this to be competitive with concrete and steel, which have a 150-year head start.”
Carbon is not the enemy
· William McDonough
Design with the natural cycle in mind to ensure that carbon ends up in the right places, urges
Carbon has a bad name. The 2015 Paris climate agreement calls for a balance between carbon dioxide emissions to the atmosphere and to earthbound carbon sinks1. Climate Neutral Now, a United Nations initiative, encourages businesses and individuals to voluntarily measure, reduce and offset their greenhouse-gas emissions by 2050. The American Institute of Architects has challenged the architecture community worldwide to become carbon neutral by 2030. The Carbon Neutral Cities Alliance, an international network of urban-sustainability directors, aims to slash its cities' greenhouse-gas emissions by 80% by 2050.
‘Low carbon’, ‘zero carbon’, ‘decarbonization’, ‘negative carbon’, ‘neutral carbon’, even ‘a war on carbon’ — all are part of the discourse. If we can reduce our carbon emissions, and shrink our carbon footprint, the thinking goes, we can bring down the carbon enemy. It’s no wonder that businesses, institutions and policymakers struggle to respond.
But carbon — the element — is not the enemy. Climate change is the result of breakdowns in the carbon cycle caused by us: it is a design failure. Anthropogenic greenhouse gases in the atmosphere make airborne carbon a material in the wrong place, at the wrong dose and for the wrong duration. It is we who have made carbon toxic — like lead in our drinking water or nitrates in our rivers. In the right place, carbon is a resource and a tool.
Carbon dioxide is the currency of photosynthesis, a source of Earth’s capacity for regeneration. Soil carbon is the guarantor of healthy ecosystems and food and water security. Carbon atoms are the building blocks of life. Wool, cotton and silk are carbon compounds, as are many industrial polymers and pure ‘supercarbons’ such as diamonds and graphene.
After 30 years of designing sustainable buildings and landscapes that manage carbon, I believe it is time to breathe new life into the carbon conversation. Rather than declare war on carbon emissions, we can work with carbon in all its forms. To enable a new relationship with carbon, I propose a new language — living, durable and fugitive — to define ways in which carbon can be used safely, productively and profitably. Aspirational and clear, it signals positive intentions, enjoining us to do more good rather than simply be less bad.
Words drive actions
It is easy to lose one’s way in the climate conversation. Few of the terms are clearly defined or understood. Take ‘carbon neutral’. The European Union considers electricity generated by burning wood as carbon neutral — as if it releases no CO2 at all. Their carbon neutrality relies problematically on the growth and replacement of forests that will demand decades to centuries of committed management2. Another strategy is to offset fossil-fuel use by renewable-energy credits — this still means an increase in the global concentration of atmospheric CO2.
Even more confusing is the term ‘carbon negative’. This is sometimes used to refer to the removal of CO2 from the atmosphere. For example, Bhutan’s prime minister has indicated that his country is carbon negative, because its existing forests sequester more CO2 than the country emits and Bhutan exports hydroelectric power (see go.nature.com/2es9lgt). But aren’t trees having a positive effect on atmospheric carbon, and hydroelectric power a neutral one?
Carbon sequestration is a long-sought goal. It requires two elements: a way to capture carbon from the atmosphere or a chimney and a way to store it safely and permanently. But some so-called carbon-storage methods are paradoxical. For example, in enhanced oil recovery, CO2 is injected into rock formations to flush out remnant crude oil, which is eventually burned.
At the same time, enterprises are starting to announce their hopes to be ‘carbon positive’ by, for example, producing more renewable energy than their operations require, or by sequestering carbon through planting trees.
Such terms highlight a confusion about the qualities and value of CO2. In the United States, the gas is classified as a commodity by the Bureau of Land Management, a pollutant by the Environmental Protection Agency and as a financial instrument by the Chicago Climate Exchange.
A new language of carbon recognizes the material and quality of carbon so that we can imagine and implement new ways forward (see ‘The new language of carbon’). It identifies three categories of carbon — living, durable and fugitive — and a characteristic of a subset of the three, called working carbon. It also identifies three strategies related to carbon management and climate change — carbon positive, carbon neutral and carbon negative.
Start with the soil
How do we work with the carbon cycle to preserve and enhance the benefits it naturally provides? From the soil up.
Carbon is at the heart of soil health. In healthy ecosystems, when plants convert CO2 into carbon-based sugars — liquid carbon — some flows to shoots, leaves and flowers. The rest nourishes the soil food web, flowing from the roots of plants to communities of soil microbes. In exchange, the microbes share minerals and micronutrients that are essential to plants’ health. Drawn into the leaves of plants, micronutrients increase the rate of photosynthesis, driving new growth, which yields more liquid carbon for the microbes and more micronutrients for the fungi and the plants. Below ground, liquid carbon moves through the food web, where it is transformed into soil carbon — rich, stable and life-giving. This organic matter also gives soil a sponge-like structure, which improves its fertility and its ability to hold and filter water.
This is how a healthy carbon cycle supports life. This flow kept carbon in the right place in the right concentration, tempered the global climate, fuelled growth and nourished the evolution of human societies for 10,000 years.
Many soil researchers believe it could do so again. Ecologist and soil scientist Christine Jones, founder of the Amazing Carbon Project, describes the “photosynthetic bridge” between atmospheric carbon and liquid carbon, and the “microbial bridge” between plants and biologically active, carbon-rich soils as twin cornerstones of landscape health and climate restoration3.
David Johnson at the New Mexico State Un iversity Institute for Energy and the Environment in Las Cruces has studied the carbon–microbial bridge4. He found that the most important factor for promoting plant growth and cultivating soil carbon was not added nitrogen or phosphorus but the carbon inputs from other plants.
Design for living
Let’s keep those carbon bridges open on all landscapes — rural and urban. Let’s use carbon from the atmosphere to fuel biological processes, build soil carbon and reverse climate change. Let’s adopt regenerative farming and urban-design practices to increase photosynthetic capacity, enhance biological activity, build urban food systems, and cultivate closed loops of carbon nutrients. Let’s turn sewage-treatment plants into fertilizer factories. Let’s recognize carbon as an asset and the life-giving carbon cycle as a model for human designs.
“To enable a new relationship with carbon, I propose a new language.”
All designs — from products to buildings, cities and farms — could be carbon positive. This may take a century, but that’s how long it took us to get into our current carbon calamity. The sooner we start, the better. By 2030, our exuberantly urbanizing planet is expected to convert more habitat and farmland into cities than all previous urban growth combined. More than 2 billion urbanites will live in homes, attend schools and work in factories that are not yet built5. Despite these challenges, there are models of hope.
In 1989 my architecture firm designed a day-care facility in Frankfurt, Germany, based on ‘a building like a tree’ that could be operated by children, who would move solar shutters, open and close windows, grow food on roof terraces and irrigate the gardens with rainwater.
The idea of ‘buildings like trees’ and ‘cities like forests’ endured, and we started to approach our product, building and city designs as photosynthetic and biologically active, accruing solar energy, cycling nutrients, releasing oxygen, fixing nitrogen, purifying water, providing diverse habitats, building soil and changing with the seasons.
The Adam Joseph Lewis Center for Environmental Studies at Oberlin College in Ohio, which we designed, is a built example of this philosophy. It purifies its waste water and sewage in an on-site system that produces carbon-rich organic compost. This year the project is producing solar energy at an annual rate of 40% more than it needs. The building still relies on the electrical grid when solar energy is unavailable. Soon, with new and affordable on-site thermal and electric battery storage systems, buildings like this can be both carbon and energy positive.
In the Netherlands, Park 20|20 near Amsterdam applies these carbon-positive design strategies at the campus scale. Next door, the Valley at Schiphol Trade Park, the country’s national hub for the circular economy, will scale these and many other innovations to create an urban ecology of work, supply chains and collaborative spaces. The development will be a network of integrated buildings, landscapes and technical systems operating as a connected whole. Each building is oriented to the path of the Sun to maximize exposure during winter and shade during summer. Photovoltaic arrays and green roofs are the system’s leaves and roots, harvesting renewable energy, absorbing and filtering water, producing food and providing habitat for other living things in a vibrant, sustainable business community.
The energy sector, too, can be generously carbon positive. SunPower, based in San Jose, California, and other solar providers are developing ‘solar orchards’ — power plants that perform as working farms. Rotating arrays of elevated solar panels shade the earth and provide habitat for grassland, which captures water, nitrogen and carbon to build soil health, can include legumes to fix nitrogen, and can provide food for grazing animals, in turn providing protein and wool. By design, the power plant generates an abundance of benefits: renewable energy, biodiversity, food, soil restoration, nutrient cycling, carbon sequestration, water conservation, fibre products, and agricultural and manufacturing jobs. Thus working durable carbon creates and supports living carbon while reducing fugitive carbon, all in an economically robust and profitable model.
Such designs offer an inspiring model for climate action. It all starts with changing the way we talk about carbon. Our goal is simple and positive: a delightfully diverse, safe, healthy and just world — with clean air, soil, water and energy — economically, equitably, ecologically and elegantly enjoyed.
The circular economy
· Walter R. Stahel
A new relationship with our goods and materials would save resources and energy and create local jobs, explains Walter R. Stahel.
When my battered 1969 Toyota car approached the age of 30, I decided that her body deserved to be remanufactured. After 2 months and 100 hours of work, she returned home in her original beauty. “I am so glad you finally bought a new car,” my neighbour remarked. Quality is still associated with newness not with caring; long-term use as undesirable, not resourceful.
Cycles, such as of water and nutrients, abound in nature — discards become resources for others. Yet humans continue to 'make, use, dispose'. One-third of plastic waste globally is not collected or managed1.
There is an alternative. A 'circular economy' would turn goods that are at the end of their service life into resources for others, closing loops in industrial ecosystems and minimizing waste (see 'Closing loops'). It would change economic logic because it replaces production with sufficiency: reuse what you can, recycle what cannot be reused, repair what is broken, remanufacture what cannot be repaired. A study of seven European nations found that a shift to a circular economy would reduce each nation's greenhouse-gas emissions by up to 70% and grow its workforce by about 4% — the ultimate low-carbon economy (see go.nature.com/biecsc).
The concept grew out of the idea of substituting manpower for energy, first described 40 years ago in a report2 to the European Commission by me and Geneviève Reday-Mulvey while we were at the Battelle Research Centre in Geneva, Switzerland. The early 1970s saw rising energy prices and high unemployment. As an architect, I knew that it took more labour and fewer resources to refurbish buildings than to erect new ones. The principle is true for any stock or capital, from mobile phones to arable land and cultural heritage.
Circular-economy business models fall in two groups: those that foster reuse and extend service life through repair, remanufacture, upgrades and retrofits; and those that turn old goods into as-new resources by recycling the materials. People — of all ages and skills — are central to the model. Ownership gives way to stewardship; consumers become users and creators3. The remanufacturing and repair of old goods, buildings and infrastructure creates skilled jobs in local workshops. The experiences of workers from the past are instrumental.
Yet a lack of familiarity and fear of the unknown mean that the circular-economy idea has been slow to gain traction. As a holistic concept, it collides with the silo structures of academia, companies and administrations. For economists who work with gross domestic product (GDP), creating wealth by making things last is the opposite of what they learned in school. GDP measures a financial flow over a period of time; circular economy preserves physical stocks. But concerns over resource security, ethics and safety as well as greenhouse-gas reductions are shifting our approach to seeing materials as assets to be preserved, rather than continually consumed.
In the past decade, South Korea, China and the United States have started research programmes to foster circular economies by boosting remanufacturing and reuse. Europe is taking baby steps. The Swedish Foundation for Strategic Environmental Research (Mistra) and the EU Horizon 2020 programme published their first call for circular-economy proposals in 2014. The European Commission submitted a Circular Economy Package to the European Parliament last December. Since 2010, the Ellen MacArthur Foundation, founded by the round-the-world yachtswoman, has been boosting awareness of the idea in manufacturers and policymakers. And circular-economy concepts have been successfully applied on small scales since the 1990s in eco-industrial parks such as the Kalundborg Symbiosis in Denmark, and in companies that include Xerox (selling modular goods as services), Caterpillar (remanufacturing used diesel engines) and USM Modular Furniture. Selling services rather than goods is familiar in hotels and in public transport; it needs to become mainstream in the consumer realm.
Few researchers are taking note. Excellence in metallurgical and chemical sciences is a precondition for a circular economy to succeed. Yet there is too little research on finding ways to disassemble material blends at the atomic level. The body of a modern car incorporates more than a dozen steel and aluminium alloys, each of which needs to be retrieved.
Circular-economy knowledge is concentrated in big industries and dispersed across small–medium enterprises (SMEs). It must be brought into academic and vocational training. A broad 'bottom up' movement will emerge only if SMEs can hire graduates who have the economic and technical know-how to change business models. Governments and regulators should adapt policy levers, including taxation, to promote a circular economy in industry. And scientists should scan the horizon for innovations that could be patented and licensed to pave the way for greater leaps in splitting up molecules to recycle atoms.
There are three kinds of industrial economy: linear, circular and performance.
A linear economy flows like a river, turning natural resources into base materials and products for sale through a series of value-adding steps. At the point of sale, ownership and liability for risks and waste pass to the buyer (who is now owner and user). The owner decides whether old tyres will be reused or recycled — as sandals, ropes or bumpers — or dumped. The linear economy is driven by 'bigger-better-faster-safer' syndrome — in other words, fashion, emotion and progress. It is efficient at overcoming scarcity, but profligate at using resources in often-saturated markets. Companies make money by selling high volumes of cheap and sexy goods.
A circular economy is like a lake. The reprocessing of goods and materials generates jobs and saves energy while reducing resource consumption and waste. Cleaning a glass bottle and using it again is faster and cheaper than recycling the glass or making a new bottle from minerals. Vehicle owners can decide whether to have their used tyres repaired or regrooved or whether to buy new or retreaded replacements — if such services exist. Rather than being dumped, used tyres are collected by waste managers and sold to the highest bidder.
A performance economy goes a step further by selling goods (or molecules) as services through rent, lease and share business models4, 5. The manufacturer retains ownership of the product and its embodied resources and thus carries the responsibility for the costs of risks and waste. In addition to design and reuse, the performance economy focuses on solutions instead of products, and makes its profits from sufficiency, such as waste prevention.
For example, Michelin has since 2007 sold tyre use 'by the mile' to operators of vehicle fleets. The company has developed mobile workshops to repair and regroove tyres at clients' premises and aims to develop products with longer service lives. Worn tyres are sent to Michelin's regional plants for retreading and reuse. The Swiss company Elite uses the same strategy for hotel mattresses, and textile-leasing companies offer uniforms, hotel and hospital textiles and industrial wipes as a service.
Conventional waste management is driven by minimizing the costs of collection and disposal — landfill versus recycling or incineration. In a circular economy, the objective is to maximize value at each point in a product's life. New jobs will be created and systems are needed at each step.
Commercial markets and collection points are needed for users and manufacturers to take back, bring back or buy back discarded garments, bottles, furniture, computer equipment and building components. Goods that can be reused may be cleaned and re-marketed; recyclables are dismantled and the parts are classified according to their residual value. Worn parts are sold for remanufacturing, broken ones for recycling. These markets used to be common — milk and beer bottles and old iron were once collected regularly from homes. Some have re-emerged as digital global market places, such as eBay.
Professional marketplaces (perhaps online) also need to be set up for the exchange of used parts, such as electric motors, bearings and microchips. Even components of liquid waste, such as lubrication and cooking oils or phosphorus from sewage, can be refined and resold. Scientists should re-market rather than dump their used kit.
Stewardship rules are needed for used goods. Austria is a world leader in this area. Collecting and reusing 'waste' are labour intensive and expensive, but they have been fostered in the nation through taxation changes and by recouping costs through re-marketing rather than scrapping parts.
The ultimate goal is to recycle atoms. This is already done for some metals. The Brussels-based company Umicore extracts gold and copper from electronic waste. The Swiss firm Batrec removes zinc and ferromanganese from batteries. These processes are energy-intensive and recover the metals only partly. To close the recovery loop we will need new technologies to de-polymerize, de-alloy, de-laminate, de-vulcanize and de-coat materials.
“We will need new technologies to de-polymerize, de-alloy, de-laminate, de-vulcanize and de-coat materials.”
Methods and equipment are needed to deconstruct infrastructure and high-rise buildings. For example, the ANA InterContinental hotel in Tokyo was demolished in 2014 beneath a 'turban' that was lowered hydraulically floor by floor to minimize noise and dust emissions. A vertical shaft with a goods lift in the middle of the building allowed the deconstructors to recover components and sort materials while using the lift as a generator.
Services liberate users from the burden of ownership and maintenance and give them flexibility. Examples include: 'power by the hour' for jet and gas turbines; bike and car rentals; laundromats and machine-hire shops. Fleet managers benefit from resource security — the goods of today become the resources of tomorrow at yesterday's prices. Covering the costs of risk and waste within the price of use or hire provides economic incentives to prevent loss and waste over the lifetimes of systems and products.
The circular economy is part of a trend towards intelligent decentralization — witness 3D printing, mass customization of manufacturing, 'labs-on-a-chip' in chemistry and functional services. The French car-sharing service Autolib offers people flexible, hassle-free urban mobility by using small electric cars that have low maintenance costs and can be recharged in reserved parking spaces throughout Paris. Such business models jeopardize the fundamentals of the linear economy — ownership, fashion and emotion — and raise fears in competing companies. For example, car manufacturers' strengths of mass production, patented technologies in combustion engines and gearboxes, big investments in robotic factories and global supply and marketing chains are of little use when competing with local Autolib services.
Make recycled goods covetable
Public procurement can exploit the potential of the performance economy. Yet despite some successes, governments remain hesitant. NASA decided a decade ago to buy space transport services, leading to start-up companies such as SpaceX competing for contracts using innovative, cheap and reusable equipment. Assigning maintenance costs to the private constructor of the Millau Viaduct in the south of France led the tenderer, Eiffage Construction, to develop a structure that could be erected quickly and would have minimal maintenance and liability costs over its 75-year service life.
Realizing a circular economy will take concerted action on several fronts.
Research and innovation are needed at all levels — social, technological and commercial. Economists and environmental and materials scientists need to assess the ecological impacts and costs and benefits of products. Designing products for reuse needs to become the norm, making use of modular systems and standardized components, for instance6. More research is needed to convince businesses and governments that a circular economy is feasible.
Communication and information strategies are needed to raise the awareness of manufacturers and the public about their responsibility for products throughout their service lives. For instance, it should be fashion magazines, not science journals, that bang the drum about jewellery sharing, leased jeans and rental designer handbags.
Policymakers should use 'resource-miser' indicators such as value-per-weight and labour-input-per-weight ratios rather than GDP. Policies should focus on performance, not hardware; internalization of external costs, such as emissions and pollution, should be rewarded; stewardship should overrule ownership and its right to destroy. The Internet of Things (in which everyday objects are digitally connected) and Industry 4.0 (intelligent technical systems for mass production) will boost such a shift, but also demand a policy review that considers questions of ownership and liability of data and goods7, 8.
Policies9 should promote activities that are desired by society and punish those that are not. Taxes should be raised on the consumption of non-renewable resources, not on renewable resources including human labour. Value-added tax (VAT) should be levied on value-added activities, such as mining, construction and manufacturing, but not on value-preserving stock management activities such as reuse, repair and remanufacture. Carbon credits should be given to emissions prevention at the same rate as to reduction.
Societal wealth and well-being should be measured in stock instead of flow, in capital instead of sales. Growth then corresponds to a rise in the quality and quantity of all stocks — natural, cultural, human and manufactured. For example, sustainable forestry management augments natural capital, deforestation destroys it; recovering phosphorus or metals from waste streams maintains natural capital, but dumping it increases pollution; retrofitting buildings reduces energy consumption and increases the quality of built stock10.
Marrying the three types of economy is a formidable challenge. A shift in policy focus from protecting the environment to promoting business models that are based on full ownership and liability, and that are unlimited in time, rather than imposing a two-year warranty for manufacturing quality, could transform a nation's competitiveness.