Research shows global health threat from rising CO2

Research shows global health threat from rising CO2

Researchers from Victoria have contributed to an international study showing that the nutritional quality of major food crops is depleted at the levels of atmospheric carbon dioxide expected in 2050.

Led by Dr Sam Myers at Harvard University, the study gathered data from seven locations across three continents for 40 cultivars of six crops. It was published in the journal Nature today.

The results showed that elevated carbon dioxide was associated with lower concentrations of zinc and iron in wheat, rice and legume crops and lower protein concentrations in wheat and rice crops.

The research team say the results warn of severe implications to global health, as these food crops are the staple diet of a large proportion of the global population. With dietary deficiencies of zinc and iron currently affecting about two billion people, reduced dietary access to these nutrients represents a very significant global health threat.

The research was conducted in Free Air Carbon dioxide Enrichment (FACE) sites, which allow plants to be grown in open fields at the atmospheric carbon dioxide levels expected in 2050.

The Australian Grains FACE (AGFACE) program is run by the University of Melbourne and the Department of Environment and Primary Industries Victoria, with support from the Department of Agriculture and the Grains Research and Development Corporation.

Over the past seven years crops of wheat, peas, canola and other pulses crops have been grown under elevated carbon dioxide at the AGFACE site at Horsham, in western Victoria. Here AGFACE researchers from the Primary Industries Climate Challenges Centre (PICCC) are studying the effects of future atmospheric conditions on crop yield, grain quality, soil health and pest populations.

Atmospheric carbon dioxide levels will continue to increase into at least the near future, with best estimates predicting about a 40% increase over the next 35 years. Increased carbon dioxide will support yields and plant growth through the so-called carbon ‘fertilisation effect’, but it will also have many downsides.

PICCC researcher and AGFACE program leader for the University of Melbourne, Professor Michael Tausz, is a co-author on the Nature study. He says we need to be prepared for these arising problems so that Australian crop industries can adapt to the future.

“If we are planning on breeding new crop varieties, or adopting new technologies or practices in food production to counter these drawbacks, then 35 years is not a very long time,” he said.

“What it means is that any new strategy in crop production to respond to these challenges, be it in plant breeding or agronomic management, must already be evaluated for its efficiency under the future high carbon dioxide atmosphere, where it actually has to perform.”

PICCC Director Associate Professor Richard Eckard says that although modelling has shown the impacts of climate change on agricultural production will be large, there are still a range of adaptation options that the industry can pursue.

“With adaptations we can capture the benefits and minimise the potential negative effects,” he said.

“The net effect of well-directed adaptation would be an increase in agricultural productivity by 2050.”

Co-author Dr Glenn Fitzgerald, AGFACE program leader from the Department of Environment and Primary Industries Victoria, says the AGFACE facility puts Australia in a good position to lead this type of internationally relevant research.

“The AGFACE program allows us to understand how to breed crops that can take advantage of the carbon dioxide fertilisation effect, so that we can exploit the positives of elevated carbon dioxide with increased yields, and reduce or reverse the negative impacts on grain quality,” he said.

“This will help the Australian grains industry prepare for coming changes in agricultural productivity and globally help maintain grain quality that is vital to human nutrition. There is every chance that with new varieties and appropriate management practices we can adapt to the changing environment.”

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