On the hotplate

In recent years, extreme heat and weather events have had a major impact on the wellbeing and wallets of ordinary Australians.

When floods in Queensland and New South Wales knocked out vast amounts of crops in 2022, the price of fresh produce skyrocketed. Lettuces costing $12 each left a bitter taste in the mouths of consumers.

But it’s not just the humble lettuce that’s under threat. Plant scientist Professor Owen Atkin says rising global temperatures are putting pressure on the staple crops we rely on to produce many of our favourite foods.

Atkin, who heads the Agrifood Innovation Institute at ANU, studies the impact of heat on the ability of plants to absorb carbon—an essential element needed for plants to grow and produce food.

“Crops like wheat and rice are highly sensitive to heat. Prolonged periods of higher than normal temperatures, or one-off really hot days, can cause a plant to produce much less grain than it otherwise would have,” he says.

“In the early stages of a plant’s life, hotter than expected weather affects carbon uptake, stunting the plant’s growth. In the later stages, the impact can be even more dire, with heat stress severely affecting the process of pollination.”

ANU Visiting Fellow Dr Alison Bentley says heat extremes are already affecting food production in the Asia-Pacific region.

“In the wheat and rice producing regions of South Asia, the late onset of the summer monsoon season in 2021 delayed rice planting and its subsequent harvest in the fall,” she says.

This delay led to a later than usual wheat planting. When extreme heat hit the region in March 2022, it caused significant falls in wheat yields, exacerbating instability in the global wheat supply caused by Russia’s invasion of Ukraine.

According to NASA’s Goddard Institute of Space Studies, summer 2023 in the northern hemisphere was Earth’s hottest since records began in 1880.

“If we are going to continue to produce nutritious food to feed the world’s population, we need to work quickly to breed crops that can grow under much hotter conditions,” Atkin says.

ANU researchers are working against the clock to come up with solutions to address this major climate challenge.

Atkin is leading a project on the development of heat tolerant wheat, as well as determining what makes a wheat crop able to survive, grow and produce yields under high-temperature conditions.

Professor Bob Furbank’s project on canola aims to use machine learning and satellite imagery to predict crop traits, including yield. This approach could be revolutionary for breeding grain crops that can survive under increasingly challenging conditions.

Associate Professor Benjamin Schwessinger’s work focuses on biosecurity threats, such as pests and pathogens. Collaborating with school students, he’s hoping to foster the next generation of biosecurity experts.

It’s innovative research like this that will be crucial to ensuring the crops that people have been eating for thousands of years can still thrive in a changing climate.

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An earlier version of this article referred to Dr Marco Ernst’s research on photovoltaics which looks at electricity yield, not crop yield, as was implied.