Around the world, natural disasters in the form of bushfires, earthquakes, storms, floods, cyclones and hurricanes cause billions of dollars of damage each year. In December 2021, tornadoes ripped through the Midwest and Southeast of the United States, killing 90 people and causing $US3.9 billion in damage.
In Australia, the Black Summer bushfires of 2019-20 claimed 34 lives, burned around 18 million hectares, destroyed more than 9,000 buildings (including 3,500 homes) and caused damage in excess of $103 billion, making it the nation’s costliest disaster.
In March 2021, extensive flooding, described by the then-NSW Premier Gladys Berejiklian as a “one-in-100-year event”, affected a large swathe of eastern Australia, particularly Sydney and the Mid North Coast, and resulted in $602 million in insurance claims.
Natural disasters – becoming more frequent due to the effects of climate change, increases in population, urbanisation, deforestation, and inadequate and ageing infrastructure – produce enormous amounts of waste. One 2020 study cites the 2008 Wenchuan earthquake in China, where 6,945,000 rooms collapsed and a further 5,932,500 were severely destroyed, generating 381 million tonnes of waste. When Hurricane Michael hit Florida in October 2018, the storm left 12.8 million tonnes of debris in its wake.
“Dealing with enormous quantities of debris and waste materials is one of the most significant challenges for communities in the wake of natural disasters. Often this task overwhelms local waste managers, leaving waste untouched for weeks, months or even years,” write a group of experts – Juyeong Choi, Assistant Professor at Florida State University College of Engineering; Sybil Derrible, Associate Professor of Sustainable Infrastructure Systems at the University of Illinois at Chicago; and Nazli Yesiller, Director of the Global Waste Research Institute at California Polytechnic State University – in The Conversation.
While disaster resilience has been the subject of much research, post-disaster waste removal is “a critical and under-studied problem,” Choi, Derrible and Yesiller argue. “Societies urgently need better strategies for dealing with the wastes these events leave behind.”
Post-disaster debris poses a health and safety risk, often containing hazardous materials such as household chemicals, herbicides and pesticides. Waste generated by natural disasters can also harm the environment through the emission of air pollutants and contamination of water and soil.
The trio proposes a four-pronged approach to improve the sustainable management of post-disaster waste:
1. Analyse the composition of the waste.
2. Find better approaches to recycling and reuse.
3. Design new technologies to identify hazardous components and sort the different types of waste.
4. Identify new and existing markets to promote reuse and recycling.
Post-disaster waste is “highly heterogeneous”, which means public officials often know little about its contents. Developing new technologies and management approaches using drones and artificial intelligence can assess the waste’s composition and identify materials for reuse and recycling. “Technologies that allow for fast sorting and separation of mixed materials can also speed up debris management operations,” Choi et al. write.
Properly sorted disaster materials can be used to make new products or materials, creating new markets for post-disaster waste streams.
