Future heat waves pose threat to global food supply

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

Heat waves could significantly reduce crop yields and threaten global food supply if climate change is not tackled and reversed – according to new research from the University of East Anglia.

A new study published in the journal Environmental Research Letters estimates for the first time the global effects of extreme temperatures and elevated levels of carbon dioxide (CO2) on the production of corn, wheat and soybean.

Earlier studies have found that climate change is projected to reduce corn yields globally by the end of the century under a 'business as usual' scenario for future emissions of greenhouse gases. However, this new study shows that the inclusion of the effects of heat waves, which have not been accounted for in previous modelling calculations, could double the losses of the crop.

Lead author of the study Delphine Deryng, from the Tyndall Centre for Climate Change Research at UEA, said: “Instances of extreme temperatures, brought about by a large increase in global mean temperature, can be detrimental to crops at any stage of their development, but in particular around anthesis—the flowering period of the plant.

“At this stage, extreme temperatures can lead to reduced pollen sterility and reduced seed set, greatly reducing the crop yield.”

The impacts on wheat and soybean are likely to be less profound, primarily because of the fertilisation effects that elevated levels of CO2 can have on these crops.

In plants, CO2 is central to the process of photosynthesis—the mechanism by which they create food from sunlight, CO2 and water. When there is more CO2 in the atmosphere, the leaves of plants can capture more of it, resulting in an overall increase in the biomass of the plant.

In addition, plants are able to manage their water use much more efficiently in these conditions, resulting in better tolerance to drought episodes. However, it is not clear whether these CO2 fertilization effects will actually occur in the field owing to interactions with other factors.

If the CO2 fertilization effects do occur, the researchers found that the yields of wheat and soybean are expected to increase throughout the 21st century under a “business-as-usual” scenario. But the increases are projected to be significantly offset by the effects of heat waves, as these plants are still vulnerable to the effects of extreme temperatures.

The positive impacts on soybean yield will be offset by 25 percent and the positive impacts on wheat will be offset by 52 per cent.

The researchers, from the Tyndall Centre at UEA, the Grantham Research Institute for Climate Change and the Environment (London School of Economics and Political Science, London), and Global Environmental and Climate Change Centre (McGill University, Montreal), arrived at their results using the global crop model PEGASUS to simulate crop yield responses to 72 climate change scenarios spanning the 21st century.

The study also identified particular areas where heat waves are expected to have the largest negative effects on crop yields. Some of the largest affected areas are key for crop production, for example the North American corn belt for corn. When the CO2 fertilization effects are not taken into account, the researchers found a net decrease in yields in all three crops, intensified by extreme heat stress, for the top-five producing countries of each crop.

“Our results show that corn yields are expected to be negatively affected by climate change, while the impacts on wheat and soybean are generally positive, unless CO2 fertilization effects have been overestimated,” continued Deryng.

“However, extreme heat stress reinforced by ‘business-as-usual’ reduces the beneficial effects considerably in these two crops. Climate mitigation policy would help reduce risks of serious negative impacts on corn worldwide and reduce risks of extreme heat stress that threaten global crop production.”

‘Global crop yield response to extreme heat stress under multiple climate change futures’ is published in the journal Environmental Letters on March 20, 2014.

Global crop yield response to extreme heat stress under multiple climate change futures
Delphine Deryng, Declan Conway, Navin Ramankutty, Jeff Price and Rachel Warren
Delphine Deryng et al 2014 Environ. Res. Lett. 9 034011
doi:10.1088/1748-9326/9/3/034011


Prev 1 2 Next All



Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...


Comments (0) Leave a comment 

Name
e-Mail (required)
Location

Comment:

characters left


Declining Weigh Blending System

Ranco Declining Weigh (DW) is the standard in fertilizer blending because of the speed and accuracy of the blending process. ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form