Opportunities for sustainability in the built environment

Read the full story from Racounteur.

Infrastructure and real estate present varying ESG risks to institutional investors, but there are still opportunities to fund environmentally and socially responsible construction projects that offer acceptable returns.

How to make roads with recycled waste and pave the way to a circular economy

Main Roads Western Australia

by Salman Shooshtarian, RMIT University; Savindi Caldera, Griffith University; Tayyab Maqsood, RMIT University, and Tim Ryley, Griffith University

It cost A$49 million to add 12.5 kilometres of extra lanes to Western Australia’s Kwinana Highway, south of Perth’s CBD. That’s not unusual. On average, building a single lane of road costs about about A$5 million per kilometre.

What is unusual about this stretch of extra freeway is not the money but the materials beneath the bitumen: two stabilising layers comprised of 25,000 tonnes of crushed recycled concrete, about 90% of which came from the demolition of Subiaco Oval (once Perth’s premier football ground). https://www.youtube.com/embed/jiFwKw3NTkk?wmode=transparent&start=75

Recycling building and construction materials remains the exception to the rule in Australia. The National Waste Policy agreed to by federal, state and territory governments has a target of 80% resource recovery by 2030. It’s currently about 40%.

Of the 74 million tonnes of waste generated in Australia in 2020, masonry materials comprised about 22.9 million tonnes. Plastics, by comparison, comprised about 2.5 million tonnes. Of the 61.5 million tonnes of “core waste” managed by the waste and resource recovery sector, 44% (27 million tonnes) came from the construction and demolition sector, compared with 20% (12.6 million tonnes) from households and local government activities.

Most of this waste – concrete, brick, steel, timber, asphalt and plasterboard or cement sheeting – could be reused or recycled. It ends up in landfill due to simple economics. It’s cheaper to buy new materials and throw them away rather than reuse and recycle.

Changing this equation and moving to a circular economy, in which materials are reused and recycled rather than discarded in landfill, is a key goal to reduce the impact of building and construction on the environment, including its contribution to climate change.

The economics of ‘externalities’

The fact it is more “economic” to throw materials away than reuse them is what economists call a market failure, driven by the problem of “externalities”. That is, the social and environmental costs of producing, consuming and throwing away materials is not reflected in the prices charged. Those costs are instead externalised – borne by others.

In such cases there is a legitimate – and necessary – role for governments to intervene and correct the market failure. For an externality such as carbon emissions (imposing costs on future generations) the market-based solution favoured by most economists is a carbon price.

For construction material waste, governments have a few more policy levers to help create a viable market for more recycling.

Using procurement policies

One way to make recycling more attractive to businesses would be to increase the cost of sending waste materials to landfill. But this would likely have unintended consequences, such as illegal dumping.

The more obvious and effective approach is to help create more demand for recycled materials through government procurement, adopting policies that require suppliers to, for example, use a minimum amount of recycled materials.

With enough demand, recyclers will invest in further waste recovery, reducing the costs. Lower costs in turn create the possibility of greater demand, creating a virtuous circle that leads to a circular economy.

Diagram of the circular economy
Australian Government, Sustainable Procurement Guide: A practical guide for Commonwealth entities, 2021

Australia’s federal, state and territory governments all have sustainable procurement policies. The federal Sustainable Procurement Guide states the Australian government “is committed to transforming Australia’s waste into a resource, where most goods and services can be continually used, reused, recycled and reprocessed as part of a circular economy”.

But these policies lack some basic elements.

Three key market-making reforms

Our research suggests three important reforms could make a big difference to waste market operations. This is based on interviewing 27 stakeholders from the private sector and government about how to improve sustainable procurement.

First, government waste policies that set aspirational goals are not supported by procurement policies setting mandatory minimum recycled content targets. All contractors on government-funded construction projects should be required to use a percentage of recycled waste materials.

Second, the nature of salvaging construction materials means quality can vary significantly. Cement recycled from a demolition site, for example, could contain contaminants that reduce its durability.

Governments can help the market through regularly auditing the quality of recycler’s processes, to increase buyer confidence and motivate suppliers to invest in production technologies.

Third, in some states (such as Western Australia) the testing regimes for recycled construction products are more complex than that what applies to raw materials. More reasonable specifications would reduce compliance costs and thereby the cost of using recycled materials.

Salman Shooshtarian, Research Fellow, RMIT University; Savindi Caldera, Research Fellow and Project Development Manager, Cities Research Institute, Griffith University; Tayyab Maqsood, Associate Dean and Head of of Project Management, RMIT University, and Tim Ryley, Professor and Head of Griffith Aviation, Griffith University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Virtual conferences are better for the environment and more inclusive

Read the full story from the University of Texas at Austin.

A research team led by engineers found that virtual conferences are more inclusive than in-person events, and also carry a smaller environmental footprint.

Finding the recipe for a larger, greener global rice bowl

Read the full story from the University of Nebraska-Lincoln.

A global assessment of rice yields and efficiency in 32 rice cropping systems concluded that there is still substantial room to increase rice production while reducing the negative environmental impacts. A leading agronomist describes the study as ‘the most comprehensive global evaluation of production systems for a major staple crop, (one that) will set the standard for future global comparison.’

‘Super trees’ may help save Houston … and beyond

Read the full story from Rice University.

Statisticians are sharing strategies to identify ‘super trees’ for urban areas that help mitigate pollution, flooding and heat.

Climate-only models likely underestimate species extinction

Read the full story from the University of Arizona.

To accurately predict species’ distributions and risk of extinction, models must include more than just climate, according to new research.

Chronic exposure to air pollution may increase risks for ICU admission or death among COVID-19 patients, study finds

Read the full story from the The Mount Sinai Hospital / Mount Sinai School of Medicine.

A new study suggests that persistent exposure to air pollutants in residential communities can impact health outcomes for COVID-19 patients.

Circular economy: Researchers show how synthetic rubber raw material can be degraded

Read the full story from Martin-Luther-Universität Halle-Wittenberg.

Enzymes are capable of degrading synthetic polyisoprene. The specific conditions for that have now been created and exploited. Polyisoprene is the principal component of natural rubber and of many types of rubber also used in car tires, for example. Up until now, it has only been possible to degrade polyisoprene, with a composition similar to naturally occurring rubber. The present research could provide important insights toward a circular economy.

Exposure to toxic metals may increase risk of clogged arteries

Read the full story from the American Heart Association.

Toxic metals in the environment may increase the risk of atherosclerosis, a buildup of plaque in the arteries that can prevent blood and oxygen from reaching major organs. Arsenic and cadmium, metals that can be found in food, water and tobacco, plus titanium, which can come from dental and orthopedic implants, cosmetics or auto manufacturing, were associated with a higher likelihood of having clogged arteries in the neck, leg and heart in this study of auto assembly workers in Spain.

Current global environmental, occupational and food safety standards may be insufficient to protect people from the adverse effects of metals, according to study authors.

Mixing steel and wood to cut construction emissions

Read the full story at Anthropocene.

A new computational tool developed by researchers at MIT could let architects and engineers lower the carbon footprint of buildings and bridges. The tool helps designers pick the best material that minimize carbon emissions of trusses, those crisscrossing structures of beams and struts used to construct bridges, antenna towers, and buildings.