9. Chocolate, Peanut Butter, Beer… What’s the Future for My Favorite Foods?

One way to make classroom discussion of the impacts of climate change more immediate is to look at specific foods. Between 2012 and 2016, the National Oceanic and Atmospheric Administration (NOAA) periodically issued “Climate and …” reports on a variety of popular foods. (At the time of this writing, these reports are still available).1 A few examples:


What if you had to choose between chocolate and endangered habitat?

Cacao trees (Theobroma cacao) only grow within about 20° north and south of the equator. They require conditions including fairly uniform temperatures, high humidity, abundant rain, nitrogen-rich soil, and protection from wind. In 2014, the Intergovernmental Panel on Climate Change (IPCC) predicted that under a “business as usual” scenario the world’s primary cacao-growing regions would experience a significant increase in temperature and a marked reduction in suitable cultivation area by 2050.3

The problem isn’t so much heat itself as it is evapotranspiration from soil and plants, since the affected regions may have insufficient rainfall to keep pace with the higher temperatures. The changing conditions would push suitable cacao cultivation areas to higher elevations, often hilly terrain where cultivation is more difficult or otherwise less suitable (for example Ghana’s Atewa Range, a forest preserve where cultivation isn’t permitted). A 2013 study examined 294 locations in West Africa; 89.5 percent were judged to be likely to become less suitable by 2050. According to the NOAA report, “Cacao-growing countries may have to choose which priority matters more: growing a product to meet a global demand, or preserving natural habitat.”

Possible adaptation strategies include breeding seeds for drought resistance and employing a traditional cacao cultivation method, known in Brazil as cabruca, that involves retaining or replanting other rainforest trees to provide cacao trees with shade and protection from erosion (while, incidentally, sequestering more carbon).

Peanut Butter4

With climate change, peanut butter could one day become a luxury item.

The peanut (Arachis hypogaea) is not a nut, but rather an annual legume that requires up to five months of fairly consistent warmth, combined with about 20 to 40 inches of rain at the right time. But the 2009 US Global Change Research Program report “Global Climate Change Impacts in the United States” concluded that temperatures would rise, and spring and summer precipitation levels would likely drop, in peanut-growing states if greenhouse gas emissions continued to increase at a high rate.5

Some observers speculate that carbon dioxide—the greenhouse gas most often credited with boosting temperatures—might be a boon because it boosts plant growth. A University of Florida study examined this possibility for peanuts, and concluded that the benefits of elevated CO2 were dwarfed by the costs of higher temperatures.6 “Peanuts like warmth,” says the NOAA report. “They don’t particularly like hell.”

Researchers are seeking to breed peanuts better able to withstand the new conditions, and exploring farming practices such as conservation tillage and even inducing early-season drought. (Peanut plants subjected to dry conditions early in the growing season appear to pre-adapt to dry conditions later in the season.)


In 2015, a number of leading breweries signed a “climate declaration” to call attention to the effects of climate change on the beer industry. “Warmer temperatures and extreme weather events are harming the production of hops, a critical ingredient of beer that grows primarily in the Pacific Northwest,” they said. “Rising demand and lower yields have driven the price of hops up by more than 250 percent over the past decade.”8

Seventy-three percent of hops in the United States are grown in the state of Washington, primarily in the Yakima Valley on the eastern side of the Cascade Mountains. Craft brewers in particular prize flavorful varieties of hops that have been developed specifically for the Yakima climate. In recent years, the area has experienced record high temperatures and extreme drought, conditions which some researchers believe will be the “new normal” by mid-century.

Not only is the availability of some valued varieties of hops threatened, but drought conditions and reduced snowpack are posing problems with the ingredient that constitutes up to 95 percent of breweries’ product and is often the centerpiece of their marketing (Olympia Beer: “It’s the water”; Coors: “Mountain sparkling water”; Zephyrhills: “Pure water. Great beer”). Breweries are facing the prospect of having to replace clean running water with groundwater, which can be heavy in minerals. “It would be like brewing with Alka-Seltzer,” said Jeremy Marshall, head brewer at Lagunitas Brewery.9


American lobster (Homarus americanus) populations are remaining relatively stable, but their locations are shifting north in response to warming sea surface temperatures, which is bad news for many fishing communities. The lobster industry in New York and southern New England has nearly collapsed.

“It’s not that southern New England lobsters are getting up and moving,” according to Jonathan Hare, director of the NOAA Northeast Fisheries Science Center laboratory in Narragansett, Rhode Island. Rather, the number of juvenile lobsters that make it to adulthood has dropped in southern New England and risen sharply in the Gulf of Maine. Some studies show that sea surface temperatures in the Gulf of Maine are warming 99 percent faster than the rest of the planet, and researchers are asking whether the migration may continue progressing north, into Newfoundland and beyond the Gulf of St. Lawrence.

Lobsters are healthiest in waters up to 68°F (20°C). Above that, they hit a “stress threshold.” Prolonged exposure to warmer water causes problems with their respiratory and immune systems, increases chances of shell disease, and makes it harder for the animals to successfully reproduce. A newly identified lobster disease, paramoebiasis, is caused by parasites that invade and engulf nervous tissue, causing death in lobsters with weakened immune systems.

Lobsters aren’t the only marine species under stress. A 2016 NOAA Fisheries Climate Vulnerability Assessment examined 82 species in the Northeast and concluded that half of them have “very high” or “high” vulnerability to climate change, in particular those such as lobsters, scallops, and clams, which live on the ocean bottom and have limited mobility.


Optimal coffee-growing conditions include cool to warm tropical climates, rich soils, and few pests or diseases. Coffea arabica, the species grown for roughly 70 percent of worldwide coffee production, has an optimal temperature range is 64°F to 70°F (18°C to 21°C). Above those moderate temperatures, fruit development and ripening accelerate, which degrades coffee bean quality. Continuous exposure to temperatures up to and just over 86°F (30°C) can severely damage coffee plants, stunting growth, yellowing leaves, even spawning stem tumors.

A study by South African researchers working in Tanzania found the most significant variable appears to be nighttime temperature. Arabica needs cool nights. For each one-degree Celsius rise in nighttime temperatures, Arabica coffee yields declined by an average of 302 pounds per hectare, almost half of the typical small producer’s entire yield. Between 1996 and 2015, average nighttime temperatures rose 1.4ºC, and Tanzanian production fell by 46 percent.12

Meanwhile, the coffee berry borer beetle, Hypothenemus hampei, appears to thrive under warming conditions, already causing US$500 million in losses, while a severe outbreak of the coffee rust fungus has been attributed to higher temperatures and rainfall.

“In short,” concludes the NOAA report, “warming climate may hurt coffee in multiple ways—reduced growing area, increased pests, and loss of quality. And while these changes may prove inconvenient or expensive for coffee drinkers, for coffee growers the effects could be catastrophic. Much of the world’s coffee production depends on farmers living at a subsistence level, and many of them grow only coffee, not food crops. For millions of small farmers, loss of their coffee-growing income would create real hardship.”

Fish Sticks13

The primary fish used for fish sticks is Alaska pollock (Theragra chalcogramma), which range through the northern Pacific Ocean, most commonly in the Bering Sea.

Climate change affects the availability of the pollock’s preferred food, zooplankton. Sea ice in the Bering Sea grows during the winter and melts during the summer, and researchers have found correlations between the persistence of sea ice through the spring, the presence of zooplankton the following summer, and the health of young pollock. At the same time, rising temperatures bring another threat. The arrowtooth flounder (Atheresthes stomias), which feeds on juvenile pollock, likes warmer water.

Systems Perspective: “About eight years ago,” notes Phyllis Stabeno of the Pacific Marine Environmental Laboratory, “we thought if the Bering Sea warmed, Alaska pollock would like warmer water, and would spread all across the Bering Sea, but we didn’t take into account the drop in zooplankton. There are always winners and there are always losers in a changing system, but who those winners and losers will be is hard to predict.”

If fish sticks aren’t that important to you, why should you care? Alaska pollock are also the fish of choice for McDonald’s Filet-O-Fish® and other fast-food fish sandwiches and are regularly used in fish and chips and imitation crabmeat, among other dishes. According to Greenpeace, Alaska pollock is the world’s largest fishery.14 It’s one of the most economically valuable. Pollock play an important ecosystem role, as staple foods for multiple other species, including salmon, tuna, other larger fishes, whales, sea lions, and seals.15 Climate threats to the pollock become threats to the health of the whole ecosystem.