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A REGISTRATION NUMBER of migrants trying to enter the United States across its southern border. Central Americans are among them: in October nearly 53,000 people from El Salvador, Guatemala and Honduras were arrested on the country’s southern border. People from the Northern Triangle, as these countries are collectively known, have many reasons to leave their homes, from poverty and gang violence to the lure of better wages in the United States. A new paper definitively points to another cause: climate change. Using border sensing data from 2012 to 2018, researchers from the universities of Texas and Utah show that more people travel north during drier-than-normal growing season conditions (see chart ).
Previous studies had linked climate change to migration patterns on a global scale, but none had shown it to be true for Central America. The researchers were able to rule out weather as a factor by controlling for other factors including poverty and violence. They received information from authorities in the United States about the more than 300,000 people who were apprehended at the United States border between 2012 and 2018, including their hometowns and towns.
They then found data on temperature and rainfall for the countries. By mapping the two they saw how drier than normal weather in growing seasons predicted migration. In areas that suffered from a very bitter growing season, there were 1.7 times more people traveling to the United States than those with normal weather. The correlation was strongest in 2015, when eight of the ten areas with the highest migration rates were those that experienced drier growing seasons than usual.
The impact of climate change on livelihoods is particularly acute in the Northern Triangle as large sections of the population depend on farming. According to data from the International Labor Organization, 37% of Hondurans, 32% of Guatemalans and 30% of Salvadoreans of working age worked in agriculture in 2012. Many other jobs also depend on the sector. Although the share of people working in agriculture had fallen in all three countries by 2019, this fall is unlikely to reduce migration, as extreme weather events are becoming more common.
The administration of President Joe Biden promised to help Central America to address the main causes of migration. So far efforts have been focused primarily on creating jobs within the private sector in the area. This study shows that more attention needs to be paid to the effects of climate change. Some international organizations, such as the International Fund for Agricultural Development, a UN agency, are running projects to reduce the impact of the climate on farmers. They include the implementation of irrigation systems and more sustainable crop rotation. But many people have to find jobs outside of agriculture, whether at home or abroad.■
