How does the weather impact what we see at the grocery store?
Wild weather impacts what food is on the shelf in your store and how much it costs, but it’s not the weather in your area that’s most important, nor is weather the only factor at play.
In today's interconnected global food system, the availability and pricing of food on grocery store shelves are influenced by a multitude of factors. One significant factor is the impact of climate change on agricultural production. As a scientist with extensive experience in the agri-food sector, I have witnessed firsthand how weather patterns can disrupt supply chains, affect crop growth, and ultimately influence what consumers see in their local grocery stores.
I was recently on the SeedSpeaks podcast to share my thoughts on the intricate, delicate, precarious relationship between the weather we experience and the food that’s available to feed ourselves and our families.
The role of temperature in crop growth
Unsurprisingly, weather plays a critical role in the growth of agricultural crops. Temperature, in particular, is a key factor that determines plant growth rates. Every crop has its specific temperature range for optimal growth, and deviations from these ranges can significantly impact the yield. Most food crops, such as fruits, vegetables, grains, and legumes, fall into the category of C3 plants, which are more sensitive to extreme heat.
When temperatures rise above the threshold for a specific crop, plant physiology becomes stressed, and growth rates decrease. This sensitivity to extreme heat can disrupt pollination processes, leading to reduced yields and potentially affecting crops like soybeans, tomatoes, peppers, and others. Prolonged periods of extreme heat, particularly during the critical stages of crop development, pose a significant risk to food production.
The earth is likely shifting into the El Niño weather pattern, which will mean a new spike in temperatures and an expectation of smashing temperature records. By 2024, we should expect even hotter temperatures, which will certainly affect food production and availability.
How growers mitigate the negative impact of extreme weather
Growers have a long list of tactics to lessen the impact of extreme weather on their crops, including using reflective plastic mulch to cool soil, frost cover to prevent sensitive crops from cold snaps, running large fans or even heaters, and spraying crops down with overhead irrigation before an expected cold snap.
Irrigation is an essential tool for bolstering plant health. However, regions that are most affected by extreme heat, such as the western edge of the corn belt (Missouri, Kansas, Oklahoma, Nebraska) and areas like California and Arizona, often face water shortages. While recent periods of rainfall in California have improved the situation, the past two decades have been dominated by drought conditions, with the region experiencing the worst megadrought in over a millennium.
While increasing water provisioning is a feasible strategy for broad-acre crop production, other approaches, such as shade cloth or whitewashes, are employed in high-value berry crops cultivation. Nonetheless, for C3 crops, there are inherent physiological limits to their tolerance of extreme weather conditions, making it challenging to completely mitigate the negative impacts.
In addition to using strategies to modify the environment, farmers can also select late blooming or cold tolerant crop varieties, or bolt-resistant heat tolerant ones at the other end of the spectrum. Weather, both heat and water, is truly a Goldilocks problem: too hot and too cold are issues – crops need their temperature and moisture to be just right.
Weather elsewhere affects what’s available at your local grocery store
The impact of weather on grocery store shelves is multifaceted and influenced by various factors. Recent disruptions in the food supply chain, whether caused by the pandemic, recalls, cyber-attacks, trade disputes, or weather-related incidents, have become more commonplace in recent years.
The changing structure and geography of the production, processing, and distribution segments of the food system have also played a significant role in determining which weather patterns matter. Concentration of production in specific regions, such as the West in the United States, has made crops vulnerable to weather-related challenges in those areas. Droughts, flooding, and freezes have disrupted production in California, Florida, Texas, and other key agricultural regions.
In the words of a 2019 FMI report, “fresh foods are … what brings shoppers to the store.” However, as the United States has become a net importer of fruits and vegetables, especially during the winter months, the weather conditions in Mexico, Canada, Peru, Chile, Central America, and the Caribbean have a significant impact on the availability of produce on store shelves year-round. It is crucial to consider the weather not only at the production sites but also along transportation routes, at major ports of entry, and at distribution centers.
The lag effect and economic implications on your wallet
Weather impacts on store shelves can occur both in the short term and with a lag effect. Acute shortages may result from recent weather events, such as blizzards, freezes, excessive rainfall, or early heatwaves, disrupting supply chains or destroying crops. When extreme weather delays planting, such as in spring 2023 in California, there can be as much as a 5-month lag between the weather event for annual crops that spend 1 to 4 months growing and when it arrives in a grocery store. These acute disruptions can cause temporary out-of-stock situations or price surges.
Source: Economic Research Service
Globally, we are in the midst of some of the highest food inflation we’ve seen in decades. Of course, there are a lot of factors contributing to inflation, but weather-related disruptions of both production and distribution is one. However, it’s probably not the weather in your neighborhood that is the issue. It’s more likely flooding, fire, or drought in the West or Mexico that is causing the issue, although which region matters most varies by product type and time of year.
