Nozomi Shima | Eating in harmony with the planet

As summer heats up, a stroll through the farmers market offers the sweet smell of ripe strawberries and peaches. The warm temperatures are making it the best time to enjoy these fruits, as well as raspberries, melons, zucchini, and more. The colder months bring the peak freshness of other produce, such as oranges, broccoli, and carrots.

The abundance of produce available year-round in supermarkets makes it easy for us to forget the correlation between climate and harvest seasons. However, recent shifts in timing – particularly the earlier ripening observed in highly climate-sensitive crops such as wine grapes – present a sign of the ongoing impact of climate change on agricultural ecosystems.

HOW DO WE HAVE PRODUCE YEAR-ROUND?

Thanks to food preservation technology, agricultural techniques, and increased global trade, we can now enjoy fresh produce any time we want it, and for items that cannot be grown locally, they can be grown in regions with optimal growing conditions and imported. For example, fruits that do not grow naturally in the US in the dead of winter can be sourced from countries experiencing the summer heat in the Southern Hemisphere. For instance, Chile, which has summer during the US winter, supplies 98 per cent of America’s imported peaches.

Some fresh produce can be stored for extended periods until it’s sold. Climacteric crops, such as bananas, tomatoes, apples, and avocados, continue to ripen after harvesting due to increased respiration and ethylene production, which accelerates the ripening process. To ensure longer shelf life, these crops are often picked early and allowed to ripen during transport. In contrast, hardy non-climacteric crops like potatoes, carrots, and onions do not continue ripening after harvest. They are picked when ripe and stored in controlled conditions to prevent spoilage.

Farmers have begun cultivating new varieties of crops, like strawberries, designed for extended harvest seasons and grown in weather-resistant systems to ensure year-round production.

HOW IS CLIMATE CHANGE AFFECTING AGRI PRODUCTION?

Despite the luxury of being able to buy a huge range of fresh produce all year round, climate change poses significant challenges to food production, including extreme weather events that harm soil health and water supplies and increased pest and disease outbreaks. With global average temperatures projected to rise to 4.4 degrees Celsius by the end of the century and increasingly erratic changes in precipitation patterns expected, agricultural regions will face disruptions that threaten crop yields and food production.

Temperate climates are experiencing more intense and unpredictable weather patterns that harm the growth of a wide variety of fruits, vegetables, and nuts. The tropics, an area surrounding the equator, are facing severe floods due to increased precipitation. In the mid-latitudes, prolonged droughts and higher temperatures are straining water supplies and disrupting the phenology, or cyclical patterns, of plants.

Elevated winter temperatures deprive crops of a winter chill period, a necessary phase for trees to start blooming and developing fruits. This leads to inconsistent, delayed, and decreased fruit development, overall reducing the yield in fruits such as apples, pears, and wine grapes. Warmer springs and summers and milder winters also worsen pest outbreaks, further threatening yields.

To combat these issues, farmers have implemented adaptation strategies such as constructing protective structures, namely plastic or glass tunnels and greenhouses equipped with artificial light, heat, sprinkler, and wind systems. These methods maintain the microclimate, allowing for earlier or later harvesting, and support a year-round production season in crops such as strawberries. As a long-term strategy, new varieties of crops are also being developed to enhance resilience against climate change.

In response to water scarcity, farmers have also tested the use of water-saving tactics, including the utilisation of desalinated water or wastewater for irrigation on crops such as olives, apples, peaches, and almonds. Another popular strategy to maximise water use efficiency is deficit irrigation, a controlled process of underwatering crops to encourage plant adaptation and achieve a higher quality with reduced water consumption.

Climate change threatens valuable horticultural crops such as tomatoes, whose production is projected to decrease six per cent by 2050 due to increased heat stress on the plants. In high tomato-producing regions, including Southern California and Italy, water constraints may limit current levels of production. However, cooler regions with historically higher precipitation such as Northern California and China – other major tomato producers – may benefit from rising temperatures, inadvertently adopting conditions that favour tomato growth.

THE CLIMATE CHANGE CANARY

Highly sensitive to acute shifts in climate, grapes serve as both a valuable agricultural product and a crucial indicator of the impact of climate change. They truly are the equivalent of the canary in the coal mine. With 49 per cent of grapes used to make wine and spirits, the industry is already seeing the effects of changing weather patterns in yield and quality. Global wine production decreased by 9.6 per cent from 2022 to 2023, a significant decline marking the lowest output since 1961.

Wine-producing regions could see a 20 to 70 per cent reduction in suitable surface area by 2100, with 90 per cent of traditional wine regions in Spain, Italy, Greece, and Southern California at risk of disappearing due to excessive drought and heatwaves. While coastal and lowland areas will be the most jeopardised, drought will almost certainly disrupt production in important winemaking regions such as Bordeaux, Tuscany, and Rioja.

While wine grapes can be cultivated in most places in the world, small climate variations significantly impact the taste, sweetness, acidity, alcohol content, and overall quality of wine. Climate change is threatening historically reputable wines, with too-high temperatures producing wine with high alcohol contents and low acidity, and too-cool temperatures producing wine with overly acidic and green notes.

Over the past several decades, the industry has begun to adapt to warmer temperatures by moving harvest seasons earlier by two to three weeks and cultivating drought-resistant vine varieties. Farmers have also implemented low-water systems and irrigation to combat water scarcity.

Regions with cooler climates may increase their suitability for wine cultivation and enhance production in up to 25 per cent of existing wine regions. Expanding new regions of wine production northward could create a net increase of 60 per cent of suitable growing regions. However, this will require converting wildland, which will impact land use and natural resources.

While changing grapevine variety is one of the most promising strategies to adapt to changing climates, wine producers may struggle to make the switch because of the demand for already-existing varieties. In the future, consumers may have to search for their preferred wines by region of origin, rather than variety, due to the increasing constraints on high-quality wine production.

HOW CAN WE EAT IN HARMONY?

Just as the seasons change and farmers adapt to cultivate their crops in changing climates, it is vital to keep an open mind and strive to eat in harmony with the planet. Eating locally reduces emissions from transport, production, and land-use change, which account for 19 per cent of energy usage in the food system. Embracing seasonal produce can provide fresher and more nutritious food that contain fewer chemicals and preservatives, while also being easier on your wallet. Careful planning and proper storage can reduce food waste. Buying from farmers who use regenerative agriculture practices, such as no-till farming and using cover crops, helps improve soil health.

As we head to the farmers markets this summer, let’s savour the best produce the season can offer. Naturally.

Nozomi Shima is studying environmental analysis and media studies at Pitzer College in Southern California. This past summer, she was a writing and communications intern at EARTHDAY.ORG in Washington, DC. Send feedback to columns@gleanerjm.com.