AUSTIN (KXAN) — Despite a focus on crime, poverty, and political unrest in Central America, weather conditions appear to be among the most significant factors when it comes to predicting immigration to the United States’ southern border.

A study by researchers at the University of Texas at Austin and the University of Utah tracked more than 323,000 migrants traveling with family from Guatemala, El Salvador, and Honduras.

It found that conditions one standard deviation drier than usual contributed to a nearly 71% increase in migration to the U.S.

The data was gathered based on U.S. Border Patrol apprehensions between 2012 and 2018, along with weather data from the cities where migrants reported being from.

When compared to the impacts of social and economic issues, University of Texas Professor Josh Busby said weather conditions were, “as, if not more important.”

Dr. Busby was previously a senior climate advisor in the Biden administration and is one of the study’s co-authors.

As for why drought is driving people north, Busby said it’s all about survival.

“This is an area that’s already known for dry and hot temperatures,” he said. “Farmers are on the margins of being able to make a go at making a living, and it’s just getting harder and harder for them to do that.”

While a lack of water is often the biggest weather issue for farmers, the study said that soaring temperatures can also cause problems, including in coffee beans, one of the region’s most important crops.

The study states that the World Food Program and International Organization for Migration recently called attention to rising food insecurity among nearly 3.5 million people living in the “dry corridor” that runs through all three countries.

Busby says that climate change is only making conditions worse for people in the region who depend on the agriculture industry.

“One way to address it would be to support smallholder agriculture and alternative livelihoods in the region,” he said. “The other would be guest worker programs in the U.S. because it’s harder for people to get in. They want to stay longer, but if they have the opportunity to come and go back and support their families that would make things a lot easier.”