The University of Queensland (UQ) has developed sophisticated new modelling which details the impacts of global warming on plants.

Developed by UQ’s leading crop scientist, Professor Graeme Hammer, the new modelling system details how the projected increase in global temperature will impact on the growth and yield of agricultural crops.

Previously it has been accepted wisdom that the yield losses being experienced by maize growers during hot seasons in the American mid-west were attributable to temperature increases. 

The modelling study has shown that it is the associated increase in the evaporative demand for water – causing increased plant water use – that will ultimately cause the decline in crop yield. 

It is not a direct effect of heat stress on plant organs from the increase in temperature. 

“These two factors are often related, but until now we were simply attributing projected yield declines to increases in temperature and heat stress – and it's more complex than that,” Professor Hammer said. 

“Our computer models are able to separate the mechanisms and explain what is actually going on. 

“Increasing temperatures mean increasing demand for water and so greater plant water use and ultimately more water stress during the crop life cycle. 

“A good human analogy would be to imagine someone standing in a desert. 

“You would start to sweat more as the temperature increased and more rapidly use up your reserves of water. 

“It's a relatively simple concept, but one that has been overlooked until now.”