Climate change triggered the classic Mayan war.

The reconstructed Bonaparte murals can be traced back to the late classical period. Will global warming lead to more wars? A new study investigates the relationship between climate change and conflicts between Mayans, who believe this and clearly point out the connection between rising temperature and intensified conflicts.

This study, published in the Quaternary Science Review, studied the history of the Mayans for about 500 years from 363 to 888.

This is the so-called classic period of prosperity of Central American civilization. Its people built huge cities and pyramids and developed one of the earliest writing systems in America.

The Mayans began the tradition of recording historical events on stone tablets.

"Translated inscriptions usually provide a very detailed description of myths and political events, including conflicts between city-states," said a report written by Mark Keller De, research chairman of Simon Fraser University in British Columbia, Professor of Archaeology at Aberdeen University in Scotland, Christopher Carlton and david campbell of Simon Fraser University.

Related: American doctors urge action on climate change, saying health problems are increasing. The researchers classified the inscriptions on monuments related to violent struggles and compiled the temperature and rainfall records of the areas where people lived in the classical period: the lowlands of Yucatan Peninsula, including parts of southern Guatemala and Mexico. And Belize.

* * * There are 144 unique conflicts on the monuments of more than 30 major Mayan centers. The research team then compared the conflict records with paleoclimate data, and the results were impressive.

"Between 350 and 900 AD, the degree of conflicts changed greatly," they wrote, and the number of conflicts increased from 0 every 25 years in the first two centuries to 3 and 24 in the last 25 years.

They pointed out that the intensification of the conflict cannot be explained by the change of rainfall. Colade told Explorer magazine: "There have been many discussions about the influence of climate change on classical Mayan civilization, but the focus of this discussion is drought." Our research shows that we have been looking in the wrong place and need to observe the influence of temperature more carefully.

Experts believe that rising temperatures may lead to greater conflicts, which have two potential mechanisms.

One is psychological-when the temperature rises, the temper will become grumpy. Several studies show that the increase of average temperature in summer may make the classic Maya more aggressive.

Related: The damage of climate change to mental health can be terrible.

Collard and his colleagues found that another mechanism is more likely, attractive and economical, and involves the main crop of the Mayans-the traditional Mayan crop: corn.

Throughout the classical period, the average temperature fluctuated between 82.4 degrees Fahrenheit (28 degrees Celsius) and 84.2 degrees Fahrenheit (29 degrees Celsius). When the temperature is 82.4 degrees Fahrenheit (28 degrees Celsius) or lower, the corn yield is quite stable, with little or no food shortage and conflict.

However, as the temperature continues to rise, the temperature in this area has been 86 F (30 C) or higher for several days, and crops are often in short supply. During the whole typical period, large-scale deforestation caused by urban expansion aggravated this effect and increased the regional temperature by reducing the availability of soil moisture. As a result, the shortage of food led to the intensification of contradictions.

"Small changes in the climate year after year will have a huge negative impact in the long run. This is a problem for us humans, because most of us