Mexico’s Gastronomy Under Threat

This year’s Climate and Society class is out in the field (or lab or office) completing a summer internship or thesis. They’ll be documenting their experiences one blog post at a time. Read on to see what they’re up to.

By Monica Morales, Climate and Society 2014

From early in the morning on a workday to the wee hours after a party, from my grandmother’s home to one of the world’s finest restaurants, at every Mexican table, corn is king. It’s not just one type of corn, but numerous varieties used for different dishes. Yet climate change could threaten the diversity of maize.

Mexican maize varieties. Photo: Ezequiel Soto Sanchez.

Pozole, blue and white tortillas, tamales, elotes, popcorn, atole, pinole, esquites. All these dishes use maize as their main ingredient. But there is an ideal type of corn for each one thanks to a 6,000-year process of domestication and specialization that started in central Mexico.

There, maize originated as a teosinte, a wild, skinny and ungraceful grass. Some farmers deemed it a weed to get rid of. So how did this grass came to be the maize we know?

While some farmers shunned teosinte, others domesticated it and over thousands of years, farmers selected the maize seeds that best adapted to their region, their climate and their soil. After all, Mexico has a complex geography and climate with high mountains, searing deserts and dense jungles.

The selection process eventually gave rise to a variety of maize plants, each with a different flavor, texture and color. All told, there are more than 200 landraces across Latin America that differ widely not just in physical appearance but also their growth rates and their resiliency to diseases and drought. In short, corn might seem simple at first glance but there’s astonishing genetic richness. As Mexican-born Nobel prize winner Octavio Paz once said, the discovery of maize by the Mexicans equaled humanity’s discovery of fire.

Climate change means radical alterations of the conditions in which maize thrived. Among the things that I’ve learned working with C3MP, a research team at NASA Goddard Institute for Space Studies, is that crop models are useful tools to assess the impacts of a changing climate on plant yields.

Models take into account plants’ processes such as photosynthesis, respiration, and solar and water intake and let researchers see how a plant would grow in response to different environmental variables. Most models show that maize has a limited response to higher CO2 levels (though that’s still a subject being researched) and that it can somewhat handle water stress. Ultimately, rising temperatures are likely to be the main factor that could decrease yields.

While a warmer climate will benefit some agricultural regions, already warm regions will be adversely affected, including parts of Mexico. I also learned while researchers know that climate change is likely to cause shifts in some extreme weather events and the range of pests, weeds and diseases, modeling their exact impacts is difficult.

While the genetic richness might be the key to adaptation for some maize races, other varieties more sensitive to the new climate will be lost and with them, a part of our Mexican heritage.