[NEW YORK] The world’s food crops are already severely affected by rising global temperatures, which exceeded 1.5 degrees Celsius above pre-industrial levels for the first time last year.

Now scientists have predicted how 30 food crops will be impacted by climate change under different warming scenarios, ranging from 1.5 to four degrees Celsius.

A study published in Nature Food shows how changes in temperature, rainfall and aridity will significantly reduce the availability of land suitable for growing these foods.

“Increasing targeted investments in climate-resilient crops, advanced irrigation techniques, and soil management strategies are foundational climate actions for the agriculture sector.”

Srijirta Dasgupta, climate change specialist, CABI

Low-latitude countries, including many in the Middle East, South Asia, Sub-Saharan Africa, and Latin America, will be worst affected, according to researchers from Aalto University in Espoo, Finland.

Up to about a third of crop production in these countries would be at risk as climate conditions became unfavourable under a rise of two degrees Celsius. This could rise to as much as half with three degrees of warming.

“The results show that crop production in the equatorial region is the most vulnerable to the changing climate conditions, adding further pressure to the already insufficient food supply in parts of the region,” says Sara Heikonen, a doctoral researcher who led the study with the university’s Water and Development Research Group.

The changing climate, along with other socio-economic factors, will also cause crop diversity in low-latitude regions to decline, the researchers found.

“The loss of diversity means that the range of food crops available for cultivation could decrease significantly in certain areas,” explains Heikonen.

“That would reduce food security and make it more difficult to get adequate calories and protein.”

Rice, maize, wheat, potato, and soybean––key staple crops which account for more than two-thirds of the world’s food energy intake––will be severely affected, Heikonen warns.

However, the study is also the first to cover some less-researched crops such as cowpea and cassava.

“Tropical root crops such as yam, which are key to food security in low-income regions, as well as cereals and pulses, are particularly vulnerable,” adds Heikonen.

“In Sub-Saharan Africa, the region which would be impacted most, almost three quarters of current production is at risk if global warming exceeds three degrees Celsius.”

Mid- and high-latitude areas, on the other hand, are unlikely to lose suitable cropland and will probably see an increase in crop diversity, say the researchers. However, other factors could still affect agriculture in those areas, says co-author Matti Kummu. He says: “Warming might bring new pests and extreme weather events, which our model doesn’t include. “The situation isn’t really that black and white.”

https://www.scidev.net/global/wp-content/uploads/globalanom_gis_2024.mp4

Click video to view change over time. Source: The Earth Observatory (NASA)

The researchers say their findings highlight the need to limit global warming to two degrees above pre-industrial levels. “Crossing this threshold would notably increase the negative effects on both current production and potential crop diversity,” says Heikonen.

But to secure food systems into the future, adaptation is equally important, she adds.

This could include developing new climate-resilient crop varieties, promoting local, underutilised crop species, improving agricultural management such as irrigation and fertilisation, or agroforestry, she suggests.

Advancing knowledge

Kyle Davis, an assistant professor and graduate director of the Geography and Spatial Sciences Department at the University of Delaware, in the US, says the study explores a previously understudied aspect of future food production under climate change.

“There has been a lot of attention to understanding the effects of climate change and variability on crop yields, but we do not have a good grasp on how cropping patterns may shift,” he tells SciDev.Net.

“This study provides a contribution towards advancing that knowledge.”

He believes many of the solutions are already available: “Today and throughout history, farmers have innovated in a variety of ways to adapt to changing climatic conditions.

“Many of the tried-and-true methods used by farmers will likely play an important role in determining future patterns of food production including selective breeding … irrigation, switching crops to more climatically suitable varieties, and incorporating the benefits of natural systems.”

Climate action plans

Srijirta Dasgupta, a climate change specialist at the agricultural research organisation CABI (the parent organisation of SciDev.Net), believes the research comes at a crucial time when scientific evidence confirms that each year is warming at a rate faster than the last and several countries are updating their Nationally Determined Contributions, which detail their commitments to tackling climate change.

“Adaptation and mitigation actions are identified as priorities in almost all the NDCs of the Asia countries,” she says.

The regions highlighted in the study as being most vulnerable are heavily reliant on agriculture, says Dasgupta, adding: “These are also the regions that have deep pockets of poverty, and the threats from climate change will catalyse hunger, malnutrition and conflict over resources.”

There will also be dire consequences for the world’s 500 million smallholder farmers, responsible for producing around a third of the world’s food, says Dasgupta.

“It should be of utmost priority for countries now to consider how these communities have a fair, inclusive and just transition to the new realities,” she adds.

Dasgupta believes countries need to make their climate actions “quantifiable” through specific climate and agriculture investment plans.

“Increasing targeted investments in climate-resilient crops, advanced irrigation techniques, and soil management strategies are foundational climate actions for the agriculture sector,” she says.

“Additionally, it is equally important that finance is channeled to the communities that are most in need.”

This piece was produced by SciDev.Net’s Global desk.