Proverbs such as "waste not, want not" seem to have fallen out of fashion in an era marked by the relentless extraction of natural resources - everything from metals to wood, food crops and building sand for the construction industry.Now, amid renewed warnings that global extraction levels are not sustainable, South African resource experts are also worried about the slow pace of domestic waste recovery and plans to establish a more resource-efficient "circular economy".The latest report by the UN's International Resource Panel notes that while the human population has doubled over the past 50 years, the rate of resource extraction has tripled.The 2019 Global Resources Outlook, compiled by a panel of 39 science experts, predicts that annual resource extraction could soar to 190-billion tons within the next four decades (more than double the current rate of 92-billion tons, and seven times higher than 1970s extraction rates).The panel says arresting such rapid extraction will require concerted action to decouple resource depletion and environmental damage from economic growth and human wellbeing.But it can be done, writes lead author Bruno Oberle, a professor of the green economy and resource governance at the Swiss Federal Institute of Technology: "We can improve how we extract, process and use natural resources, and how we dispose of the resulting waste."Professor Linda Godfrey, principal scientist in the Waste for Development research group at SA's Council for Scientific and Industrial Research, says the most recent statistics suggest that SA recycles only about 10% of the waste it generates.Godfrey, who is also manager of the department of science & technology's 10-year Waste Roadmap Implementation Unit, said the 90% of resources lost to the economy through landfilling equates to about R17bn a year.Though recycling rates of 100% are unlikely to be achieved, Godfrey said SA "can do much better", especially with the recovery of metals in waste electronic products such as old computers and cellphones, and with construction and demolition waste, or the organic waste from food, farms and gardens.The most recent baseline data (based on 2011 surveys) suggests that some of the highest recovery rates from South African waste streams include metals (about 80%) paper (57%) waste oils (44%) and glass (32%).Though this data indicates only 11% of plastic is recycled, the industry group Plastics SA said the recycling rate increased to 44% of all domestically made plastic in 2017.Godfrey said SA's paper and packaging waste recovery rates are among the best in the world, but this had happened "almost by accident rather than design" - driven by poverty and unemployment, which mobilise a large, informal waste-sorting sector."To my mind, increasing waste diversion into reuse, repair or recycling is about making it more difficult to dump at the local landfill. We are 20 to 30 years behind Europe in terms of how we manage our waste, and in our adoption of alternatives to landfilling."She said Europe had followed a trajectory from simple dumping to engineered landfilling to incineration to greater recycling, supported by policy instruments, including implementing landfill taxes and, later, incineration taxes. "We also need to change the way we view our resources and to design products for longevity," she said.Under current economic models of ownership, products are designed to wear out, whereas sharing models (where consumers hire or lease products such as washing machines or cars) would provide more incentives to design products that will last.Professor Cristina Trois, an environmental engineer who is overseeing several new waste-recovery research projects at the University of KwaZulu-Natal, said nothing should go to waste - not even cow heads.Several of these projects involve "green concrete" - incorporating industrial and domestic waste into construction materials or roads. Examples include a pilot project in Durban to collect the bones and skulls of cattle that are normally dumped in landfill sites, incorporating them instead into road construction material.Trois, recently awarded a new National Research Foundation/CSIR research chair to focus on climate change and waste management, said decades of research into the more efficient use of waste resources are not being implemented fast enough.Other research projects include making better use of the fibrous properties of papermill sludge to enhance the strength of green concrete, along with using alien water hyacinth weeds, which choke dams and rivers.Scrap rubber tyres and plastic fibre could also be used as additives when surfacing municipal roads, and organic waste from farms and municipalities could be sold for use in energy production."We are trying hard to find funding to move some of these pilot projects out of the lab and into the field, especially for alternative building materials," said Trois. "But unless you can incentivise companies or municipalities to reuse more waste resources, the circular economy will not be activated."The Minerals Council SA (formerly the Chamber of Mines) said the organisation "seeks to play a leadership role in discussions on lowering the industry's environmental footprint, including in respect of energy efficiency".Commenting on initiatives to reduce mineral resource extraction in SA, the council said: "This is not a matter that is or can be co-ordinated on a collective basis in respect of individual member companies. For one thing, there could be competition law issues. "However, we have noted an announcement by Glencore in February of a commitment to limit coal production. The country earns 25% of its international trade income/foreign exchange through minerals exports, a number equivalent to half its average foreign currency reserves of $25bn [R354bn]." The council said operational factors had driven resource efficiency. "Mining companies have responded to power supply constraints and huge tariff increases by increasing efficiencies since at least 2008."..