Global Warming, Indian Ocean Heat Have Pushed Australian Wheat Yields Down Sharply
Global heating in the Indian Ocean has shifted a climate pattern towards drier conditions across Australia’s globally important wheat belt causing a severe drop in yields over the past three decades, according to a new study. Scientists from Australia and China warned as global heating continues, wheat-growing conditions would become more challenging. The study, published in Nature Food, analysed different climate phenomena that influenced Australia’s rainfall since the late 1800s and used models to see how this affected wheat yields.
Global heating has caused a shift in a climate pattern known as the Indian Ocean Dipole which, when it’s in a positive phase, can starve wheat growers of rain. The number of positive IOD events had risen markedly in recent decades, corresponding with a drop in rainfall and falling yields. In good years, the average wheat yield could reach 2.5 tonnes a hectare but in drier years with positive IOD events, the yield would drop well below 1.5 tonnes a hectare.
The researchers used models that account for other factors that can influence wheat yield, such as crop management, sowing time, or the varieties planted. The study comes as Australia is being heavily affected by the alternate negative phase of the IOD that is contributing to major downpours across the south and east of the continent.
A lead author of the study, Dr Bin Wang, a climate research scientist at the New South Wales government’s Department of Primary Industries, said: “The Australian wheat crop totally depends on rainfall. A positive IOD typically sees below average winter and spring rainfall. That means the wheat yield is decreased. “The climate warming is a major driver in bringing more occurrences of these positive IOD events.”
EDIT
https://www.theguardian.com/australia-news/2022/oct/14/australian-wheat-yields-plummet-after-decades-of-global-heating-study-finds
= new reply since forum marked as read
