Our food system isn’t ready for the climate crisis


We used to eat so many different varieties of corn

Maize or corn is now grown in greater volume than any crop in history, and is still the staple food for about 1.2 billion people in Latin America, the Caribbean and sub-Saharan Africa.

A man kneels among a spread of drying maize

A farmer in spreads recently harvested maize for drying in Bangalore, India, where maize is the third most important cereal after wheat and rice. Photograph: Getty Images

But the maize most of us eat today is quite different from what our ancestors consumed.

Maize spread around the world because of its ability to evolve and adapt to different climates, altitudes and day lengths. Left to mother nature in an open field, diversity flourishes as wind carries pollen from one plant to a female flower of another plant, creating a slightly different maize baby every time.

According to USDA research geneticist Sherry Flint-Garcia, “open love pollination” enabled maize to adapt to different environments as intrepid humans took it further and further from its centre of origin in southwest Mexico, where it crossed with other wild and cultivated varieties.

From there, farmers would save and replant the seeds of the best plants – the hardiest, tastiest, and easiest to harvest – to create locally adapted varieties, which are called landraces or heirlooms. By the early 20th century, there were thousands of distinct landraces being cultivated from Canada to Chile, each one adapted to the local ecosystem with its own good and bad quirks.

Dozens of landrace specimens laid out on a black background

Diverse maize varieties stored at the International Maize and Wheat Improvement Center’s genebank in Texcoco, Mexico. Photograph: CIMMYT Germplasm Bank

This story is true for most of our staple crops.

For thousands of years, families and communities relied on these local landraces which over time had developed helpful traits for their particular ecosystems. These landraces would also have not-so-good traits, but farmers saved, shared, and bought and sold seeds locally which helped the best varieties evolve and thrive. Different crops like maize, beans and squashes were planted in the same field to help control pests, fertilize the soil and provide a nutritionally balanced diet.

For maize, this changed radically around the 1920s, after scientists discovered they could take a landrace and self-pollinate the plant, creating a genetically identical inbred, and if they did this several times its characteristics would change – perhaps the plant would be taller or have a big ear of corn. These inbreds were then crossed with each other, again and again, to create hybrids.

Locally adapted breeds of maize have a lot of variation.

The plants with the most desirable traits can be bred with themselves several times.

The result is an inbred with consistent traits, like larger kernels.

When inbreds are mixed, we can get hybrids with beneficial traits like larger ears or more kernels.

 

These genetically homogenous hybrids have taken over the food system.

Locally adapted breeds of maize have a lot of variation.

The plants with the most desirable traits can be bred with themselves several times.

The result is an inbred with consistent traits, like larger kernels.

When inbreds are mixed, we can get hybrids with beneficial traits like larger ears or more kernels.

 

These genetically homogenous hybrids have taken over the food system.

Locally adapted breeds of maize have a lot of variation.

The plants with the most desirable traits can be bred with themselves several times.

The result is an inbred with consistent traits, like larger kernels.

When inbreds are mixed, we can get hybrids with beneficial traits like larger ears or more kernels.

 

These genetically homogenous hybrids have taken over the food system.

Locally adapted breeds of maize have a lot of variation.

The plants with the most desirable traits can be bred with themselves several times.

The result is an inbred with consistent traits, like larger kernels.

When inbreds are mixed, we can get hybrids with beneficial traits like larger ears or more kernels.

 

These genetically homogenous hybrids have taken over the food system.

Hybrid seeds, which farmers have to replace every year, contributed to a huge increase in yield but at the expense of genetic diversity and qualities like taste, nutrition and climate adaptability. In the blink of an evolutionary eye, Mexico lost 80% of its varieties, and 99% of corn grown in the US today is from hybrid seeds.

As agriculture became increasingly industrial and corporate, many farmers were incentivized or pushed into monocropping homogenous high-yield varieties that depend on expensive and greenhouse gas generating synthetic fertilisers, pesticides and machines. Over the last century, modern genetically narrow varieties have taken over much of the world’s farmland.

In 1970, the large majority of farm land in Asia and Africa was used for local varieties of crops.

1.56m sq km

of local varieties

200,000 sq km

of modern varieties

About 40 years later, far more land in 2010-14 was used for modern varieties that often lack genetic diversity.

In 1970, the large majority of farm land in Asia and Africa was used for local varieties of crops.

1.56m sq km

of local varieties

200,000 sq km

of modern varieties

About 40 years later, far more land in 2010-14 was used for modern varieties that often lack genetic diversity.

In 1970, the large majority of farm land in Asia and Africa was used for local varieties of crops.

1.56m sq km

of local varieties

200,000 sq km

of modern varieties

About 40 years later, far more land in 2010-14 was used for modern varieties that often lack genetic diversity.

In 1970, the large majority of farm land in Asia and Africa was used for local varieties of crops.

1.56m sq km

of local varieties

200,000 sq km

of modern varieties

About 40 years later, far more land in 2010-14 was used for modern varieties that often lack genetic diversity.

In 1970, the large majority of farm land in Asia and Africa was used for local varieties of crops.

1.56m sq km

of local varieties

200,000 sq km

of modern varieties

About 40 years later, far more land in 2010-14 was used for modern varieties that often lack genetic diversity.

In 1970, the large majority of farm land in Asia and Africa was used for local varieties of crops.

1.56m sq km

of local varieties

200,000 sq km

of modern varieties

About 40 years later, far more land in 2010-14 was used for modern varieties that often lack genetic diversity.

As a result we lost countless varieties of grains, fruits, vegetables and spices better equipped – thanks to their genetic makeup which evolved over generations  – to withstand certain pathogens, drought, heat, and humidity. 

History shows us that diversity really matters. In 1970, a new fungus called southern corn leaf blight wiped out 15% of maize crops in the US and southern Canada, as susceptibility was tied to a genetic sequence used in all popular hybrids. Today around 43% of maize grown in America is still derived from just six inbred lines.

Like an investor with stocks, savings and real estate, diversity in the field spreads the risk: if an early season drought wipes out one crop, there will be others which mature later or are naturally more drought tolerant, so farmers aren’t left with nothing.

Wheat feeds billions – but it’s vulnerable to climate changes too

We can tell a similar story about wheat, the most widely consumed grain globally which is grown in every continent (apart from the Antarctic) to make bread, chapattis, pasta, noodles, pizza and biscuits eaten by billions of people.

Aerial view of a tractor running through a wheat field

A farmer bales up straw after harvesting a field of wheat in Northamptonshire, England in September 2021 when the country experienced a heatwave. Photograph: PA Wire

Global wheat production tripled thanks to the Green Revolution in the mid-20th century after an American scientist in Mexico, Norman Borlaug, developed a short-stemmed variety which could withstand the weight of fertilizers. This changed the way the world farmed: uniformity, yield and technology became the gold standard, and malnutrition declined substantially despite population growth. But this came at a huge cost, namely the loss of wheat diversity, natural ecosystems and traditional knowledge, and climate change is now making us pay.

Last year prices for durum (pasta) wheat soared by 90% after widespread drought and unprecedented heatwaves in Canada, one of the world’s biggest grain producers, followed a few months later by record rainfall. Over the last century, Canadian farmers have increasingly relied on genetically similar high yield wheat varieties, elbowing out crucial diversity.

Canadian wheat varieties have been getting more genetically similar over the last century.

0.25 genetic dissimilarity

More genetically similar

to each other

Year variety was released

Canadian wheat varieties have been getting more genetically similar over the last century.

0.25 genetic dissimilarity

More genetically similar

to each other

Year variety was released

Canadian wheat varieties have been getting more genetically similar over the last century.

0.25 genetic dissimilarity

More genetically similar

to each other

Year variety was released

Canadian wheat varieties have been getting more genetically similar over the last century.

0.25 genetic dissimilarity

More genetically similar

to each other

Year variety was released

Luigi Guarino, director of science of the Crop Trust, said: “Climate change is the greatest threat to food security, there is nothing bigger. Under very unpredictable conditions, the more diversity in farmers’ fields the better.”

Our favorite coffee is threatened by hurricanes and rain storms

The first US coffee house opened in Boston in 1689, and today Americans drink about 400m cups every day. Coffee is produced in 80 or so tropical countries, so one might think diversity is inevitable.

But whether you prefer espresso or instant, it comes from just two species: smooth tasting, high quality arabica accounts for about two thirds of consumption and is struggling to cope with the changing climate; and Robusta, which is hardier with more caffeine and higher yields but has a bitter, grainy flavor.

Historical drawing of the Green Dragon Tavern, a colonial structure with people standing in the foreground.

The Green Dragon Tavern was one of Boston’s first and most celebrated coffee house taverns, opened in 1697. Photograph: Boston Public Library

Wild arabica coffee is native to the forested mountains of Ethiopia and South Sudan, but the coffee we enjoy in our lattes and flat whites today can be traced back to just two sets of arabica plants snuck out of Yemen in the early 17th Century.

Its future now hangs in the balance. 

Arabica grows at 1,300 to 2,000 meters above sea level and is very fussy about temperature, rainfall and humidity. When it’s too hot and dry, coffee ripens too quickly which diminishes yield and quality. Our arabica doesn’t like it to be too wet or too windy either – which is a major problem for coffee growing regions prone to hurricanes like the Caribbean, Hawaii and Vietnam. As the climate rapidly changes, higher temperatures and more erratic rainfall could render 50% of current arabica growing regions unsuitable by 2050.

“It’s like a monocrop, and the low genetic diversity is a huge part of its vulnerability,” said Sarada Krishnan, a coffee scientist and grower.

The global coffee industry, valued at $465bn in 2020, has so far failed to come up with $25m to protect the world’s four most important gene banks which hold many of the known 131 species.

By 2050, many regions where arabica coffee is currently grown, like Mexico and Central America, will likely be much less suitable for the crop.

Mexico and Central America

By 2050, many regions where arabica coffee is currently grown, like Mexico and Central America, will likely be much less suitable for the crop.

Mexico and Central America

By 2050, many regions where arabica coffee is currently grown, like Mexico and Central America, will likely be much less suitable for the crop.

By 2050, many regions where arabica coffee is currently grown, like Mexico and Central America, will likely be much less suitable for the crop.

By 2050, many regions where arabica coffee is currently grown, like Mexico and Central America, will likely be much less suitable for the crop.

By 2050, many regions where arabica coffee is currently grown, like

Mexico and Central America, will likely be much less suitable for the crop.

It’s not just heat. Pathogens threatening coffee include insects, moths, worms and coffee leaf rust – a fungus now found in every single coffee-growing country, and which removes the ability to produce beans.

Closeup of the brown and disclored rotting leaves of a coffee plant

A coffee plant infested with the deadly fungus roya – also known as coffee rust – in Heredia, Costa Ric, in 2015, which has spread across the region over the past decade due to inadequate prevention and the climate crisis. Photograph: Getty Images

About 125 million people depend on it for their livelihoods in Latin America, Africa, and Asia. But coffee leaf rust has destroyed crops in around 70% of farms in Central and South America over the past decade, contributing to a rise in poverty, child malnutrition and forced migration. The rust is not new but scientists think that unpredictable rainfall and rising temperatures are causing the fungus to reproduce more quickly – and spread more widely across plantations.

These kinds of climate threats will likely drive up prices. 

The race to save genetic diversity

Every apple eaten today can be traced back to the Tian Shan forested mountains between China and Kazakhstan, where every tree produces unique fruit in shape, size and flavor. The wild orchard has dizzying diversity, according to food journalist Dan Saldino, and hidden in the trees are drought and disease resistant traits we will need as the climate crisis increasingly puts pressure on food production.

But this living gene bank is under threat, with huge swathes already culled to make space for cash crops, cattle ranches, and housing developments. Malus sieversii, the wild apple which is the primary ancestor of all our favorite apples, has been on the IUCN red list of threatened species since 2007. 

It’s not just apples. Vanilla is native to Mexico and Central America, but the region’s eight wild species are listed as endangered or critically endangered on the red list.

Learn moreGene banks

More than half a million different samples of wheat – landraces, wild ancestors and commercial varieties – are stored in seed collections across the world. For rice, the international gene bank in the Philippines has around 132,000 samples including 24 wild species found in Asia, Africa, Australia, and the Americas which taste, smell and look wildly different to the nutritionally devoid and bland white rice most of us know. Just outside Mexico City, the International Maize and Wheat Improvement Center (CIMMYT) gene bank holds 28,000 unique maize samples and 150,000 wheat seeds. Its slogan: “Seed security is the first step towards food security”.

Not all is lost. 

As the Green Revolution fueled the erosion of genetic biodiversity this triggered an organized global effort to find and conserve diversity in gene or seed banks.

The Global Seed Vault, a modern concrete structure, juts out of a baren snow-covered landscape

The Svalbard Global Seed Vault, built inside a mountain on a remote island halfway between mainland Norway and the North Pole for safety, contains the world’s largest collection of crop diversity. Photograph: Global Crop Diversity Trust

Thanks to these genetic goldmines, researchers are looking to wild relatives, forgotten landraces and obsolete commercial varieties to breed climate-resistant or more adaptive varieties which can withstand more unpredictability. “We’ll never get back all the diversity we had before, but the diversity we need is out there,” said Matthew Reynolds, head of wheat physiology at Cimmyt, the International Maize and Wheat Improvement Center outside Mexico City. 

The gene bank approach has been pretty successful for saving staple grains, but far less so for vegetables and fruits. And while storing seeds is no easy feat (you need carefully controlled conditions), lots of foods including coffee, apples, peaches and vanilla need to be conserved as plants or trees, which is even more complex and expensive.

In the end, we need to see greater diversity in farmers’ fields, where old varieties can once again be part of the evolutionary story.

The Global Seed Vault, a modern concrete structure, juts out of a baren snow-covered landscape

A wild banana variety native to south-east Asia, where bananas were domesticated thousands of years ago. Photograph: Fernando Garcia-Bastidas

As the clock ticks, the private sector is forging ahead with developing biotech solutions like gene editing and transgenics, which rely on genetic resources in publicly funded gene banks and naturally occurring biodiversity to provide the raw material. Just four agrochemical companies control 60% of the global seed market (and 75% of the pesticides market), and so have a vested interest in making farmers dependent on them for the full shebang.

In contrast, agroecologists and regenerative farmers argue that the most efficient and sustainable food systems are those which use techniques that mimic nature, rather than try to dominate it with artificial ones. “It’s about understanding what farmers have done for millenia to draw on traditional knowledge – and support that with current science – to deal with evolving environmental stressors including climate change,” said Alexis Racelis, agroecology professor at the University of Texas.

No matter what the approach, valuing diversity and saving endangered foods like wild arabica coffee in Ethiopian forests, vanilla orchids in Guatemala, and the apple trees in Kazakhstan is key to improving the nutritional quality of our diets, more sustainable farming, and climate adaptation, according to Dan Saladino.

“It’s not about going back, it’s about looking back with a bit of humility at the diversity and food systems that kept humans alive for thousands of years in greater harmony with nature – and looking at what can be applied in the 21st century food system.” 

  • This article is the first in a series about the diversity crisis in our food, with more coverage coming in the next few days and weeks
  • This article was amended on 19 April 2022 to correct Luigi Guarino’s job title.


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