Why we need basic sciences for sustainable development more than ever

By Michel Spiro, President of the International Union of Pure and Applied Physics (IUPAP) and President of the Steering Committee for the proclamation of the International Year of Basic Sciences for Sustainable Development in 2022 (IYBSSD 2022)

A consortium of international scientific unions and scientific organizations’ plans to declare 2022 the International Year of Basic Sciences for Sustainable Development are underway. Michael Spiro makes the case for why the world needs this now more than at any time in the past.

© Dmytro Tolokonov | Dreamstime.com

For almost a year and a half now, the world has been disrupted by the COVID-19 pandemic caused by the SARS-CoV-2 virus. But how much worse could the situation have been without the progress and results produced for decades, even centuries, by curiosity-driven scientific research?

We deplore the many deaths due to COVID-19, and the future is still very uncertain, especially with the detection of new variants, some of which are spreading more quickly. But how could we have known that the infection was caused by a virus, what this virus looks like and what its genetic sequence and variations are without basic research?

Viruses were discovered at the beginning of the 20th century, thanks to the work of Frederick Twort, Félix d’Hérelle, and many others. The first electron microscope was built in the 1930s by Ernst Ruska and Max Knoll; and DNA sequencing began in the mid-1970s, notably with research by the groups of Frederick Sanger and Walter Gilbert.

Such a list could of course go on and on, with basic research at the root of countless tests, treatments, vaccines, and epidemiological modeling exercises. We even owe high-speed, long-distance communications, which allow us to coordinate the fight against the pandemic and reduce interruptions in education, economic activities, and even the practice of science, to the discovery and study of electromagnetic waves and optic fibers during the 19th century, and the development of algorithms and computers codes during the 20th century. The COVID-19 pandemic is a reminder (so harsh and brutal that we would have preferred to have been spared) of how much we rely on the continuous development of basic sciences for a balanced, sustainable, and inclusive development of the planet.

On many other issues, basic sciences have an important contribution to make to progress towards a sustainable world for all, as outlined in Agenda 2030 and its 17 Sustainable Development Goals, adopted in September 2015 by the United Nations General Assembly. They provide the essential means to address major challenges such as universal access to food, energy, and sanitation. They enable us to understand the impacts of the nearly eight billion people currently living on the planet, on the climate, life on Earth, and on aquatic environments, and to act to limit and reduce these impacts.

Indeed, unlike our use of natural resources, the development of the basic sciences is sustainable par excellence. From generation to generation, it builds up a reservoir of knowledge that subsequent generations can use to apply to the problems they will face, which we may not even know about today.

The International Year of Basic Sciences for Sustainable Development (IYBSSD) will focus on these links between basic sciences and the Sustainable Development Goals. It is proposed to be organized in 2022 by a consortium of international scientific unions and scientific organizations* led by the International Union of Pure and Applied Physics (IIUPAP) with the recommendation of a resolution voted by the UNESCO General Conference during its 40th session in 2019. Over 50 national and international science academies and learned societies and around 30 Nobel Prize laureates and Fields Medalists also support this initiative. The Dominican Republic has agreed to propose a resolution for the promulgation of the IYBSSD during the 76th session of the United Nations General Assembly, beginning in September 2021.

We very much hope that scientists, and all people interested in basic science, will mobilize around the planet and take this opportunity to convince all stakeholders – the general public, teachers, company managers, and policymakers – that through a basic understanding of nature, inclusive (especially by empowering more women) and collaborative well-informed actions will be more effective for the global common interest. As IIASA is one of the consortium’s founding partners, we especially invite all IIASA scientists, alumni, and colleagues they are collaborating with to create or join national IYBSSD 2022 committees to organize events and activities during this international year.

More information, as well as communication material, can be found at www.iybssd2022.org. This will also be shared through social media accounts (look for @iybssd2022 on Facebook, Twitter, LinkedIn and Instagram). You are also invited to subscribe to the Newsletter here.

* Consortium members

The International Union of Crystallography (IUCr); the International Mineralogical Association (IMA); the International Mathematical Union (IMU); the International Union of Biological Sciences (IUBS); the International Union of Geodesy and Geophysics (IUGG); the International Union of Pure and Applied Chemistry (IUPAC); the International Union of History and Philosophy of Science and Technology (IUHPST); the International Union of Materials Research Societies (IUMRS); the International Union for Vacuum Science, Technique, and Applications (IUVSTA); the European Organization for Nuclear Research (CERN); the French Research Institute for Development (IRD); the International Institute for Applied Systems Analysis (IIASA); the European Physical Society (EPS); the Joint Institute for Nuclear Research (JINR); the Nuclear Physics European Collaboration Committee (NuPECC); the International Centre for Theoretical Physics (ICTP); the International Science Council (ISC); Rencontres du Vietnam; the Scientific Committee on Oceanic Research (SCOR); the Square Kilometre Array Organization (SKAO); and  SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East).

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Using the COVID-19 pandemic to transform the energy sector

By Husam Ibrahim, International Science Council (ISC)

The IIASA-ISC Rethinking Energy Solutions Report identifies the negative and positive lessons learnt from the ongoing COVID-19 pandemic in relation to energy consumption and demand, and recommends several immediate actions.

Credit: Adam Islaam – IIASA

As a result of the pandemic’s confinement and containment policies, energy demand and resulting energy-related carbon emissions declined by an estimated 2.4 billion tonnes in 2020 – a record drop according to researchers at Future Earth’s Global Carbon Project. However, the reduction is likely to be short-lived if structural changes do not occur.

The COVID-19 pandemic has caused foreseeable positive and negative disruptions to the global energy sector. This has revealed opportunities that can be learnt from to meet Sustainable Development Goals (SDGs) and the Paris Agreement pledges, with the positive disruptions showing us the possibility of a more sustainable and resilient future.

The IIASA-ISC Rethinking Energy Solutions Report recommends actions based on the opportunities and vulnerabilities in energy systems that the COVID-19 pandemic has brought to light.

“The pandemic is a threat, but also an opportunity, because it showed that the system we have spent a lot of money and resources on is not working the way it should, so the crisis should be used to draw up new budgets, take new actions, and rebuild society.”

– Behnam Zakeri, Research Scholar, IIASA

The report highlights that solutions previously thought to be out of reach are far more possible than expected. One such positive outcome is the digitalization of physical activities, such as attending work, schools, conferences, and other gatherings online. This has resulted in short-term lifestyle changes — introducing and normalizing digital solutions for a mass audience — which the report recommends capitalizing on in a post-COVID society.

Some companies, like Spotify, a music streaming service, have announced that they will let their employees work remotely from anywhere after the pandemic. The report suggests that more companies and governments should do the same, as digitalization offers opportunities to use resources more efficiently, and so has the potential to make consumption more sustainable and to reduce carbon footprints.

Efforts to digitalize and reduce the population’s carbon footprint work hand-in-hand with the need to reinvent urban spaces to reach the SDGs and combat climate change.

Cities consume 60-80% of global energy and produce more than 70% of carbon emissions. What’s more, 70% of the world’s population is projected to live in urban areas by 2050.

The report proposes that cities should be redesigned into more sustainable ‘urban villages’ so that they are optimized for energy efficiency. One way to do this would be to redesign cities into compact neighborhoods where all amenities (shops, offices, schools, etc.) are within walking distance. Paris, France, for example, promotes self-sufficient neighborhoods, with all the essential amenities placed within a 15-minute radius. Several other cities like Melbourne, Australia, with its “20-minute neighborhoods” and the Nordhavn “5-minute neighborhood” in Copenhagen, Denmark, are promoting this new standard for the use of space and sustainable mobility.

Another key approach to reinventing urban spaces is prioritizing nature-based solutions by using parks, green roofs, green walls, and blue infrastructure to combat climate change and connect the population back to nature. This also means centering public spaces around people, by converting street spaces from car use to sidewalks and bike lanes, and enhancing the quality and safety of walking and biking infrastructures.

The report also recommends that cities be rebuilt to incorporate renewable energy. The costs for renewable technologies are declining quite fast, but Zakeri explained that the problem with moving to renewable energy is not the cost but a lack of understanding. Consumers, experts, and governments lack the knowledge to distribute, access and install these technologies. However, in recent times, scientists and other experts have brought more awareness to them and are helping the trend move forward.

The report states the importance of developing net zero-energy communities that have a holistic approach to energy-efficient building renovation and construction of new buildings. The net zero-energy design must consider the energy interactions between individual buildings and the broader energy system on a local level.

These recommended actions aren’t just about energy efficiency but about creating a more fulfilling life for all.

“Rebuilding cities to be more sustainable and resilient [to future crises] not only has the potential to reduce energy consumption but also create a more joyful lifestyle that improves the wellbeing and experience of people living in a city.”

– Behnam Zakeri, Research Scholar, IIASA

For more information on rebuilding urban spaces, and addressing energy lessons from the COVID-19 pandemic read the IIASA-ISC Rethinking Energy Solutions Report.

You can also watch the discussion on Rethinking Energy Solutions as part of the launch event for the Bouncing Forward Sustainably: Pathways to a post-COVID World, which explores the key themes of Sustainable Energy, Governance for Sustainability, Strengthening Science Systems and Resilient Food Systems.

 

This blog post was first published on the website of the International Science Council. Read the original article here.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Roads, landslides, and rethinking development

By Prakash Khadka, IIASA Guest Research Assistant and Wei Liu, Guest Research Scholar in the IIASA Equity and Justice Research Group

Prakash Khadka and Wei Liu explain how unbridled, unplanned infrastructure expansion in Nepal is increasing the risk of landslides.

Worldwide, mountains cover a quarter of total land area and are home to 12% of the world’s population, most of whom live in developing countries. Overpopulation and the unsustainable use of these fragile landscapes often result in a vicious cycle of natural disaster and poverty. Protecting, restoring, and sustainably using mountain landscapes is an important component of Sustainable Development Goal 15  ̶  Life on Land  ̶  and the key is to strike a balance between development and disaster risk management.

Nepal is among the world’s most mountainous countries and faces the daunting challenge of landslides and flood risk.  Landslide events and fatalities have been increasing dramatically in the country due to a complex combination of earthquakes, climate change, and land use, especially the construction of informal roads that destabilize slopes during the monsoon.

According to Nepal government data, 476 incidents of landslides and 293 fatalities were recorded during the 2020 monsoon season – the highest number in the last ten years, mostly triggered by high-intensity rainfall – a trend which is increasing due to climate variations. According to one study, by mid-July 2020, the number of fatal landslides for the year had already exceeded the average annual total for 2004–2019.

Figure 1: A map of landslide events in Nepal from June to September 2020. Source: bipadportal.gov.np

Landslides are not a new phenomenon in the country where hills and mountains cover nearly 83% of the total land area. While being destructive, landslides are complex natural processes of land development. The Gangetic plain, situated in the foothills of the Himalayas, was formed by the great Himalayan river system to which soil is continually added by landslides and deposited at the base by rivers.  Mountain land changes via natural geo-tectonic and ecological processes has been happening for millions of years, but fast population growth and climate change in recent decades substantially altered the fate of these mountain landscapes. Road expansion, often in the name of development, plays a key role.

Many mountain areas in Nepal are physically and economically marginalized and efforts to improve access are common. Poverty, food insecurity, and social inequity are severe, and many rural laborers opt to migrate for better economic opportunities. This motivates road network expansion. Since the turn of the century, Nepalese road networks has almost quadrupled to the current level of ~50 km per 100 km2, among which rural roads (fair-weather roads) increased more than blacktop and gravel roads.

Figure 2: Mountains carved just above Jay Prithvi Highway in Bajhang district of Sudurpaschim province to build a road

Nepalese mountain roads are treacherous and subject to accidents and landslides. Rural roads, which are often called “dozer roads”, are constructed by bulldozer owners in collaboration with politicians at the request of communities (also as part of the election manifesto in which politicians promised road access in exchange for votes and support to win), often without proper technical guidance, surveying, drainage, or structural protection measures. In addition, mountains are sometimes damaged by heavy earthmovers (so-called “bulldozer terrorism”) that cut out roads that lead from nowhere to nowhere, or where no roads are needed, at the expense of economic and environmental degradation. Such rapid and ineffective road expansion happens throughout the country, particularly in the middle hills where roads are known to be the major manmade driver of landslides.

To tackle these complexities, we need to rethink how we approach development in light of climate change. This has to be done with sufficient investigation into our past actions. The Nepalese Community forestry management program, which emerged as one of the big success stories in the world, encompasses well defined policies, institutions, and practices. The program is hailed as a sustainable development success with almost one-third of the country’s forests (1.6 million hectares) currently managed by community forest user groups representing over a third of the country’s households. Another successful example is the innovation of ropeways and its introduction in the Bhattedanda region South of Kathmandu. The ropeways were instrumental in transforming farmers’ lives and livelihoods by connecting them with markets. Locals quickly mastered the operation and management of the ropeway technology, which was a lifesaver following the 2002 rainfall that washed away the road that had made the ropeway redundant until then.

These two examples show that it is possible to generate ecological livelihoods for several households in Nepal without adversely affecting land use and land cover, which in turn contributes to increased landslide risk in the country, as mentioned above.

A rugged landscape is the greatest hindrance to the remote communities in a mountainous country like Nepal. It cannot be denied that the country needs roads that serve as the main arteries for development, while local innovations like ropeways can well complement the roads with great benefits, by linking remote mountain villages to the markets to foster economic activities and reduce poverty. Such a hybrid transportation model is more sustainable economically as well as environmentally.

It is a pity that despite strong evidence of the cost-effectiveness of alternative local solutions, Nepal’s development is still mainly driven by “dozer constructed roads”.  Mountain lives and livelihoods will remain at risk of landslides until development tools become more diverse and compatible.

References:

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Crafting mines from satellite images

By Victor Maus, alumnus of the IIASA Ecosystems Services and Management Program and researcher at the Vienna University of Economics and Business

The mining of coal, metals, and other minerals causes loss of natural habitats across the entire globe. However, available data is insufficient to measure the extent of these impacts. IIASA alumnus Victor Maus and his colleagues mapped more than 57,000 km² of mining areas over the whole world using satellite images.

 

© Pix569 | Dreamstime.com

Our modern lifestyles and consumption patterns cause environmental and social impacts geographically displaced in production sites thousands of kilometres away from where the raw materials are extracted. Complex supply chains connecting mineral mining regions to consumers often obscure these impacts. Our team at the Vienna University of Economics and Business is investigating these connections and associated impacts on a global-scale www.fineprint.global.

However, some mining impacts are not well documented across the globe, for example, where and how much area is used to extract metals, coal, and other essential minerals are unknown. This information is necessary to assess the environmental implications, such as forest and biodiversity loss associated with mining activities. To cover this data gap, we analyzed the satellite images of more than 6,000 known mining regions all around the world.

Visually identifying such a large number of mines in these images is not an easy task. Imagine you are flying and watching from the window of a plane, how many objects on the Earth’s surface can you identify and how fast? Using satellite images, we searched and mapped mines over the whole globe. It was a very time-consuming and exhausting task, but we also learned a lot about what is happening on the ground. Besides, it was very interesting to virtually visit a vast range of mining places across the globe and realize the large variety of ecosystems that are affected by our increasing demand for nature’s resources.

The result of our adventure is a global data set covering more than 21,000 mapped areas adding up to around 57,000 km² (that is about the size of Croatia or Togo). These mapped areas cover open cuts, tailings dams, piles of rocks, buildings, and other infrastructures related to the mining activities — some of them extending to almost 10 km (see figure below). We also learned that around 50 % of the mapped mining area is concentrated in only five countries, China, Australia, the United States, Russia, and Chile.

Examples of mines viewed from Google Satellite images. (a) Caraj\'{a}s iron ore mine in Brazil, (b) Batu Hijau copper-gold mine in Indonesia, and (c) Super Pit gold mine in Australia. In purple is the data collected for these mines (Figure source: www.nature.com/articles/s41597-020-00624-w).

Using these data, we can improve the calculation of environmental indicators of global mineral extraction and thus support the development of less harmful ways to extract natural resources. Further, linking these impacts to supply chains can help to answer questions related to our consumption of goods. For example, which impacts the extraction of minerals used in our smartphones cases and where on the planet they occur? We hope that many others will use the mining areas data for their own research and applications. Therefore, the data is fully open to everyone. You can explore the global mining areas using our visualization tool at www.fineprint.global/viewer or you can download the full data set from doi.pangaea.de/10.1594/PANGAEA.910894. The complete description of the data and methods is in our paper available from www.nature.com/articles/s41597-020-00624-w.

This blog post first appeared on the Springer Nature “Behind the paper” website. Read the original post here.

Note: This article gives the views of the authors, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

How to reverse global wildlife declines by 2050

IIASA researchers Michael Obersteiner, David Leclère, and Piero Visconti discuss the findings of their latest paper, which proposes pathways to reverse the current trend of biodiversity loss and shows that the next 30 years will be pivotal for the Earth’s wildlife.

Species are going extinct at an unprecedented rate. Wildlife populations have fallen by more than two-thirds over the last 50 years, according to a new report from the World Wildlife Fund. The sharpest declines have occurred throughout the world’s rivers and lakes, where freshwater wildlife has plummeted by 84% since 1970 – about 4% per year.

But why should we care? Because the health of nature is intimately linked to the health of humans. The emergence of new infectious diseases like COVID-19 tend to be related to the destruction of forests and wilderness. Healthy ecosystems are the foundation of today’s global economies and societies, and the ones we aspire to build. As more and more species are drawn towards extinction, the very life support systems on which civilization depends are eroded.

Even for hard-nosed observers like the World Economic Forum, biodiversity loss is a disturbing threat with few parallels. Of the nine greatest threats to the world ranked by the organization, six relate to the ongoing destruction of nature.

© Chris Van Lennep | Dreamstime.com

Economic systems and lifestyles which take the world’s generous stocks of natural resources for granted will need to be abandoned, but resisting the catastrophic declines of wildlife that have occurred over the last few decades might seem hopeless. For the first time, we’ve completed a science-based assessment to figure out how to slow and even reverse these trends.

Our new paper in Nature featured the work of 60 coauthors and built on efforts steered by the Intergovernmental Panel on Biodiversity and Ecosystem Services. We considered ambitious targets for rescuing global biodiversity trends and produced pathways for the international community to follow that could allow us to meet these goals.

Bending the curve

The targets of the UN Convention on Biological Diversity call for global trends of terrestrial wildlife to stop declining and start recovering by 2050 or earlier. Changes in how land is used – from pristine forest to cropland or pasture – rank among the greatest threats to biodiversity on land worldwide. So what are the necessary conditions for biodiversity to recover during the 21st century while still supporting growing and affluent human societies?

Two key areas of action stand out from the rest. First, there must be renewed ambition from the world’s governments to establish large-scale conservation areas, placed in the most valuable hotspots for biodiversity worldwide, such as small islands with species found nowhere else. These reserves, in which wildlife will live and roam freely, will need to cover at least 40% of the world’s land surface to help bend the curve from decline to recovery for species and entire ecosystems.

The location of these areas, and how well they are managed, is often more important than how big they are. Habitat restoration and conservation efforts need to be targeted where they are needed most – for species and habitats on the verge of extinction.

The next 30 years will prove pivotal for Earth’s biodiversity. Leclère et al. (2020) © IIASA

Second, we must transform our food systems to produce more on less land. If every farmer on Earth used the best available farming practices, only half of the total area of cropland would be needed to feed the world. There are lots of other inefficiencies that could be ironed out too, by reducing the amount of waste produced during transport and food processing, for example. Society at large can help in this effort by shifting towards healthier and more sustainable diets, and reducing food waste.

This should happen alongside efforts to restore degraded land, such as farmland that’s becoming unproductive as a result of soil erosion, and land that’s no longer needed as agriculture becomes more efficient and diets shift. This could return 8% of the world’s land to nature by 2050. It will be necessary to plan how the remaining land is used, to balance food production and other uses with the conservation of wild spaces.

Without a similar level of ambition for reducing greenhouse gas emissions, climate change will ensure the world’s wildlife fares badly this century. Only a comprehensive set of policy measures that transform our relationship with the land and rapidly scale down pollution can build the necessary momentum. Our report concludes that transformative changes in our food systems and how we plan and use land will have the biggest benefits for biodiversity.

But the benefits wouldn’t end there. While giving back to nature, these measures would simultaneously slow climate change, reduce pressure on water, limit nitrogen pollution in the world’s waterways and boost human health. When the world works together to halt and eventually reverse biodiversity loss, it’s not only wildlife that will thrive.

This article originally appeared on The Conversation. Read the original article here.

Note: This article gives the views of the authors, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.

Cost effective solutions to manage nutrient pollution in the Yangtze

By Maryna Strokal, Department of Environmental Sciences, Water Systems and Global Change, Wageningen University and Research, The Netherlands

Maryna Strokal discusses a new integrated approach to finding cost-effective solutions for nutrient pollution and coastal eutrophication developed with IIASA colleagues.

© Huy Thoai | Dreamstime.com

Have you ever wondered why the water in some rivers appear to be green? The green tinge you see is due to eutrophication, which means that too many nutrients – specifically nitrogen and phosphorus – are present in the water. This happens because rivers receive these nutrients from various land-based activities like run-off from agricultural fields and sewage effluents from cities. Rivers in turn export many of these nutrients to coastal waters, where it serves as food for algae. Too many nutrients, however, cause the algae and their blooms to grow more than normal. Because algae consumes a lot of oxygen, this lowers the available oxygen supply in the water, killing off fish and other marine life. Some algae can also be toxic to people when they eat seafood that have been exposed to, or fed on it. Polluted river water on the other hand, is unfit for direct use as drinking water, or for cooking, showering, or any of our other daily needs. Before we can use this water, it needs to be treated, which of course costs money.

To better understand and address these issues, I worked with colleagues from IIASA, Wageningen University, and China to develop an integrated approach to identify cost-effective solutions (read cheapest) to reduce river pollution and thus coastal eutrophication. Our integrated approach takes into account human activities on land, land use, the economy, the climate, and hydrology. We implemented the new approach for the Yangtze Basin in China.

The Yangtze is the third longest river in the world and exports nutrients from ten sub-basins to the East China Sea, where the coast often experiences severe eutrophication problems that may increase in the coming years. The Chinese government has called for effective actions to ensure clean water for both people and nature.

In our paper on this work, which was recently published in the journal Resources, Conservation, and Recycling, my colleagues and I conclude that reducing more than 80% of nutrient pollution in the Yangtze will cost US$ 1–3 billion in 2050. This cost might seem high, but it is actually far below 10% of the income level in the Yangtze basin. We also identified an opportunity in the negative or zero cost range, which would result in a below 80% reduction in nutrient export by the Yangtze. This negative or zero cost alternative involves options to recycle manure on land and reduce the use of chemical fertilizers (Figure 1). More recycling means that farmers will buy less chemical fertilizers and potential savings can then compensate for the expenses related to recycling the manure. We also illustrated the costs that would be involved for ten sub-basins to reduce their nutrient export to coastal waters.

Figure 1. Summarized illustration of eutrophication causes and cost-effective solutions for reducing nutrient export by Yangtze and thus coastal eutrophication in the East China Sea in 2050.

Recycling manure on cropland is an important and cost-effective solution for agriculture in the sub-basins of the Yangtze River (Figure 1). Manure is rich in the nutrients that crops need, and opting for this alternative instead of chemical fertilizers avoids loss of nutrients to rivers, and thus ultimately to coastal waters. Current practices are however still far from ideal, with manure – and especially liquid manure – often being discharged into water because crop and livestock farms are far away from each other, which makes it practically and economically difficult to transport manure to where it is needed. Another reason is the historical practice of farmers using chemical fertilizers on their crops – it is simply how they are used to doing things. Unfortunately, the amounts of fertilizers that farmers apply are often far above what crops actually need, thus leading to river pollution.

The Chinese government are investing in combining crop and livestock production, in other words, they are creating an agricultural sector where crops are used to feed animals and manure from the animals is in turn used to fertilize crops. Chinese scientists are working with farmers to implement these solutions.

In our paper, we showed that these solutions are not only sustainable, but also cost-effective in terms of avoiding coastal eutrophication. We invite you to read our paper for more details.

References

Strokal M, Kahil T, Wada Y, Albiac J, Bai Z, Ermolieva T, Langan S, Ma L, et al. (2020). Cost-effective management of coastal eutrophication: A case study for the Yangtze River basin. Resources, Conservation and Recycling 154: e104635. https://doi.org/10.1016/j.resconrec.2019.104635.

Note: This article gives the views of the author, and not the position of the Nexus blog, nor of the International Institute for Applied Systems Analysis.