In the early 1990s, a young Australian chef named Bill Granger had a bright idea: Why not spread avocado on toast?
Nearly three decades after that successful experiment, the long and sometimes bizarre history of the avocado has reached a new and potentially controversial turning point — albeit without the Instagram potential of avocado toast. As climate change threatens the fruit’s place on brunch menus, some scientists are now asking: Why not edit its DNA?
Last month, a team of scientists in the United States and Mexico announced that it had mapped the DNA sequences of several types of avocados, including the popular Hass variety. That research is likely to become the foundation for breeding techniques and genetic modifications designed to produce avocados that can resist disease or survive in drier conditions.
Whether they realize it or not, this could be big news for toast-munching hipsters. Already, rising temperatures are disrupting the avocado supply chain, causing price increases across the United States that have also been exacerbated by trade uncertainty.
"Because of climate change, temperature might not be the same, humidity might not be the same, the soil might be different, new insects will come, and diseases will come," said Luis Herrera-Estrella, a plant genomics professor at Texas Tech University who led the avocado project. "We need to be prepared to contend with all these inevitable challenges."
The history of the avocado dates back to the Aztecs. Thousands of years later, Granger is often credited with being the first chef to serve avocado toast, which is now a staple of the millennial diet, a symbol of modern decadence and an Instagram sensation.
In an interview, Granger, perhaps the earliest avocado engineer, said he approved of the genetic research. But the project has left him with a few questions about the future of his beloved fruit.
"How are they mucking around with it?" he asked. "What are they changing?"
The answer is that the avocado is not changing — at least, not yet. In recent years, scientists have sequenced the genomes of a number of fruits, including bananas, tomatoes and apples, and have used that information to create genetically modified varieties. But a genetically modified avocado is still a long way off, partly because avocado trees can take at least three years to mature.
As climate change intensifies, however, the challenges facing the avocado industry are becoming increasingly urgent. The heat wave in California last year disrupted the development of this summer’s avocado crop, forcing suppliers to import fruit from abroad. As a result, the wholesale price of a box of four dozen avocados more than doubled to between $70 and $80, from $35, said Jim Donovan, an executive at California avocado supplier Mission Produce.
Over the next few years, heat waves will become more common, scientists and industry experts predict, potentially leading to even more severe shortages. A recent study by scientists in California estimated that climate change could reduce the state’s avocado production, which last year totaled 300 million pounds, by 40% over the next three decades.
"There are avocados that grow in very hot places with little water, and there are avocados that grow more in rainy places," Herrera-Estrella said. "If we can identify genes that confer heat tolerance and drought tolerance, then we can engineer the avocados for the future."
The development of strains of avocado capable of resisting disease or surviving long droughts could lift the Mexican agriculture industry, which produces nearly half the world’s avocados and relies heavily on exports to the United States, according to Monica Ganley, an agricultural consultant and expert on Latin American trade. Last year, Mexico exported nearly 2 billion pounds of avocados to the United States.
"It’s a really important crop; it’s a really important component of agricultural trade and has become much more so over the last several decades," Ganley said.
Of course, the role of international trade in the avocado supply chain also means that the fruit’s availability often has as much to do with politics as with climate change.
In June, President Donald Trump toyed publicly with the idea of levying tariffs on Mexico, a move that would have sent the price of avocados skyrocketing. Just a few weeks earlier, avocado prices had briefly surged at the fastest rate in recent memory after Trump threatened to close the southern border.
The fruit’s availability can also depend on drug cartels, whose violence sometimes disrupts local avocado production — another problem that genetic modification is unlikely to address.
"Science is very good and very powerful," Herrera-Estrella said. "But it doesn’t make miracles."