Global warming may lead to an increase in the number of malaria cases around the world, according to a new study. The study, which was published in the journal Science, implies that global warming trends in the future may lead to more malaria infections, especially in heavily populated portions of Africa and South America that are at higher elevations.

The research suggests that global warming trends could expose millions more people to the disease, as mosquitoes that carry the disease-causing parasite will move to higher altitudes.

Malaria is a serious, and sometimes life-threatening, disease that killed nearly 620,000 people in 2012. It is just one of several diseases that researchers believe will spread more rapidly because of global warming.

Ecologists from the University of Michigan and the London School of Hygiene and Tropical Medicine have based their study on records that have been analyzed from high altitudes in Ethiopia and Columbia. The ecologists note that mosquitoes typically travel back to lower altitudes when temperatures decrease.

The ecologists warn that unless efforts to monitor and control diseases are drastically improved, many more people will be at risk of contracting malaria.

Menno Bouma, from the London School of Hygiene and Tropical Medicine, explained to AFP that for Ethiopia, “a one-degree-Celsius increase in temperature will lift the area where malaria can occur by 150 meters.” Bouma continues, “In this band, there live about six to nine million people. These people will be additionally affected, but also people that live a bit lower, where malaria is present but at a lower level. For those people, the malaria intensity is likely to increase.”

The team of researchers looked specifically at malaria records from the highland portions of Columbia from 1990 to 2005, and from high elevation areas in Ethiopia from 1993 to 2005.

The records indicated that individuals who live in higher elevations experience an increased number of malaria infections in comparison to cooler years.

University of Michigan ecologist, Mercedes Pascual, says, “This is indisputable evidence of a climate effect.”