Study reveals how climate, weather-related food losses have wide impact

The world is heavily dependent on global food supply chains and while severe weather can damage crops and affect meat production causing shortages, what is less well studied are the ripple effects across communities and industries within a country and beyond.

Researchers from the University of Sydney investigated the effects of climate change and extreme weather on food supply chains within three major farming states in Australia: Queensland, New South Wales (NSW) and Victoria.

They found that the impact on crop and livestock production can be far and wide, stretching across states and affecting non-food sectors such as transport and services, including retail.

"While it is well known that extreme weather events can disrupt crop and food supplies, the wide-ranging indirect implications are unclear," said lead author Arunima Malik, from the university's Integrated Sustainability Analysis group in the Faculty of Science and the School of Business.

"We find that climate change and extreme weather events affect not just productivity, but also the economy and health of people.

"There is an observed loss of nutrient availability in the event of climate change or extreme weather," she told The Straits Times.

The study, published in the journal Nature Food, also found that climatic events - such as cyclones, floods, bush fires and heatwaves - could affect surrounding areas by way of limiting food availability and employment.

Co-author Manfred Lenzen, professor of sustainability research from the Faculty of Science, said a major weather disaster can devastate local rural communities, especially sustained or repeated events that lead to widespread crop and livestock losses.

This can lead to major loss of income for farmers, which cascades to the local community, such as being unable to pay bills, service agricultural machinery or buy fuel or fertiliser.

The effects of these events can also be felt in distant regions due to the complex interconnectivity of modern supply chains.

"You cannot escape these cascading effects no matter where you are because we are part of such an intricate web of interdependence. Everyone can be affected," he said.

Dr Malik's team ran a series of complex computer models analysing supply chains to assess how disruptions in food supply affected interconnected sectors and industries.

They looked at a number of scenarios related to climate change and extreme weather events that resulted in a loss of agricultural production in Queensland, NSW and Victoria - the three largest states by population - as well as the impact on employment and income and food and nutrient availability.

The study assumed no import substitution.

They found that severe weather events could lead to localised food price increases and diminished food quality, with poor households faring worse than affluent counterparts even in the same area.

Impact on food production could also affect employment and cause income losses not just in food supply chains but also in the transportation and service sectors, the authors found.

For example, one scenario for the year 2030 combining climate change impact and a cyclone in Queensland led to major losses of meat and wool production in parts of NSW, while the cyclone caused a 90 per cent drop in the banana crop.

Meat production, retail and restaurants were the sectors most affected across all regions in the study, causing large financial losses, the authors said.

In a statement, Dr Malik said the cascading effects can also trigger zoonotic diseases (spread between animals and humans), food-borne epidemics and broader social impacts such as inter-regional migration and social unrest.

"It's vital that we understand these impacts so we can build a more resilient society," she said.

Prof Lenzen said the findings are applicable globally. He explained that the databases used match the same standards set by the United Nations and statistical agencies used around the world.

"These methods can be transferred to any regions and also lead to very similar findings. Especially Singapore, Luxembourg and Switzerland, because they are more trade dependent."

Singapore, for example, imports the majority of its food.