New NASA Study Shows How Climate Change Could Impact Wheat And Maize Farming In Next 10 Years

A new NASA study says climate change may impact the production of crops such as maize and wheat in the next 10 years if greenhouse gas emissions remain high

Representational image of a wheat field | Photo: Getty

New Delhi: NASA experts will share at the ongoing International COP26 summit in Glasgow how space provides critical information to better understand our changing planet. They will provide insights into understanding climate change, NASA officials said in an update.

A new study by the space agency has found that climate change could impact the production of crops such as maize and wheat, though differently, in the next 10 years if greenhouse gas emissions remain high. 

In the study published in the Nature Food journal, the authors noted that the changing climate would make it more difficult to grow maize in the tropics, but could expand the growing range of wheat.

The study said there is a likelihood of a 24 per cent decrease in maize crop yields, but wheat yield could potentially grow by 17 per cent.

How Will Climate Change Impact Maize And Wheat Yields?

The scientists explained that the change in yields will occur due to future increases in the temperatures, changes in rainfall patterns, and higher concentrations of surface carbon-dioxide concentrations from greenhouse gas emissions caused due to anthropogenic activities. 

The researchers estimated the change using advanced climate and agricultural models. 

Growing maize in the tropics will become more difficult due to such environmental changes, but these could lead to an increase in the growing range of the wheat crop.

In the coming years, the decline in maize yield will affect regions such as North and Central America, West Africa, Central Asia, Brazil, and China where the temperatures are rising.

Temperate regions, such as the Northern United States and Canada, North China Plains, Central Asia, Southern Australia, and East Africa are likely to witness increased wheat yields within the next 10 years. 

Quoting lead author Jonas Jägermeyr, who is also a climate scientist at NASA's Goddard Institute for Space Studies (GISS), a NASA statement said the researchers had not expected to see such a fundamental shift, compared to projections from previous models conducted in 2014.

He said there would be severe implications worldwide if there is a 20 per cent decrease from current production levels of maize.

The research team used two sets of models to arrive at the results. The first model, known as the International Climate Model Intercomparison Project-Phase 6 (CMIP6), was used to simulate how Earth's atmosphere would respond to different scenarios of greenhouse gas emissions till 2100. 

Another set of models was used to simulate how crops grow and respond to different environmental conditions. 

The researchers created around 240 global climate-crop model simulations, using supercomputers, for each crop. 

The scientists also found a way to identify climate change impacts that can be easily discerned. Using projections with the new method, the team observed that soybean and rice yields can also decrease in some regions due to climate change. 

The climate effect was much clearer for maize and wheat. 

Temperature Not The Only Factor Considered

The researchers focused on many factors other than temperature while simulating the future crop yields. 

They found higher levels of atmospheric carbon-dioxide to have a positive effect on photosynthesis and water retention, which increase crop yield, but reduce the nutritive value.

The effect is more pronounced in wheat than maize, the team found.

Increasing global temperatures cause rainfall patterns to change, and thus, the frequency and duration of heat waves and droughts, all of which impact crop health and productivity.

The length of growing seasons is also dependent on temperature. Higher temperatures can accelerate crop maturity.

Alex Ruane, a co-author of the study, said the plants collect sunlight over the course of the growing season, and transfer the energy into the grains. 

He explained that shorter growing seasons mean the plant hasn't collected much energy, as a result of which the total grain production will be much less than what would have occurred with longer developmental periods.

He said by growing faster, the yield goes down.

Jägermeyr said global agriculture is facing a new climate reality, and the impacts even in one region's breadbasket will be felt worldwide due to the interconnectedness of the global food system.

The models, however, only estimate climate change impacts, and do not take into consideration economic incentives and changing farm practices, the authors noted. 

The researchers intend to include these factors in future studies as they said people's response to climate-driven changes have a significant impact on agricultural yields.