PARIS, FRANCE – From the worst drought in forty years in the Horn of Africa to record-breaking heat waves in Argentina, extreme weather triggered by climate change threatens to disrupt global agriculture, even in previously spared temperate zones.

FOOD INSPECTION
Agriculture is both a cause and a victim of global warming.

It accounts for almost a quarter of global greenhouse gas emissions – mostly from livestock and fertilizer.

But at the same time, rising temperatures, changing rainfall patterns and the increasing frequency of extreme weather events are threatening food security, according to the Intergovernmental Panel on Climate Change (IPCC).

In their latest assessment of climate change, IPCC scientists predicted that up to 80 million people would be at risk of hunger by mid-century, primarily in sub-Saharan Africa, South Asia and Central America.

Higher temperatures contribute to increased severity and frequency of droughts.

In Ethiopia, Somalia and Kenya, “five consecutive below-average rainy seasons left 23.4 million people acutely food insecure,” according to a July World Food Program report.

The drought decimated livestock and reduced local food supplies, which in turn caused food prices to skyrocket.

Then, after years of drought, severe flooding hit parts of Somalia and Kenya in November, threatening to deepen the food crisis.

In Argentina, crops were the healthiest they have been in 40 years after drought and record-breaking temperatures severely affected wheat and soybean crops, the group World Weather Attribution (WWA) said earlier this year.

In the last growing season, Argentina saw a 30% decline in corn production, the lowest since 2015. And while wheat production rose 20%, it remained lower than normal, according to the U.S. Department of Agriculture.

However, it can be difficult to directly link weather events and their impacts on crops to climate change.

According to WWA, Argentina was about 60 times more likely to experience record heat due to climate change. But while the heat exacerbated the drought’s impact on agriculture, the group could not confidently “attribute the low rainfall to climate change.”

Climate change is also leading to an increase in extreme precipitation events, which threaten crops. Too much rain rots crops, makes sowing or harvesting nearly impossible, and increases soil erosion.

Last year, floods in Pakistan led to an estimated loss of $2.3 billion in food crops after “climate change likely increased extreme monsoon rainfall in the country,” according to the WWA.

And in 2021, an unusual climate-related cold spell in France caused “very serious damage” to grape vines and fruit trees.

BIG INFLUENCE
“If there is a lack of water at the time of plant growth or just before flowering, it has a significant impact on grain production,” said Thierry Caquet from the French research institute INRAE, which studies agricultural adaptation to climate change.

“High temperature, with or without water, will inhibit the growth of the grains,” he added.

Water influences the number of ears of grain – and therefore harvest volume – while temperature influences quality.

Lack of water also leads to lack of food.

Dry water sources and a lack of grass for grazing often decimate herds in the Sahel or Horn of Africa. Even in more temperate Europe, milk production of dairy cattle breeds is reduced in high heat.

“Cattle and sheep, whose innards heat up during fermentation, are particularly sensitive to this. A heat spike of 40 degrees Celsius (104 Fahrenheit) can kill a cow,” Caquet said.

USEFUL MITIGATORS
Around 60% of the world’s food comes from rainfed agriculture, the rest is supported by irrigation.

As the world warms, the need for irrigation will increase as crops require more water to compensate for transpiration. Vegetables with a high water content, such as tomatoes and melons, are particularly stressed.

The IPCC estimates that droughts caused a 25% loss in crop yields worldwide between 1961 and 2006, calling them “a major cause of yield declines.”

If the planet warms by 1.5 to 2 degrees Celsius above pre-industrial levels, drought-related losses will increase by nine to 12 percent for wheat crops and more than 18 percent for rice crops by 2100, a report says from 2019.

There are ways to adapt agriculture to rising temperatures, such as switching to less water-intensive crops, using drought-resistant seeds, reducing soil erosion and adopting efficient irrigation systems.

But they are “much less effective at 2°C or 3°C,” the IPCC said in the report.

The UN Environment Program warned last month that the planet is on track for catastrophic warming of 2.5 to 2.9 degrees Celsius by 2100.