El Nino is not only responsible for creating an abnormal warming of ocean waters in the tropical Pacific but it has also influenced ancient civil wars, a new study has found.

The sweltering conditions created by the climatic event, El Nino, have been linked to increasing the chances of Civil War as a study carried out my Columbia University found people who get warm and uncomfortable become more irritable and are therefore more prone to fight.

People do like to fight and El Nino conditions help, said Mark Cane, a professor of Earth and climate sciences at Columbia University and co-author of the study.

Between 1950 and 2004, the risk of civil wars doubled in 90 tropical countries when hit by El Nino. Researchers say El Nino influenced 48 of 234 civil wars. They found internal strife in Chad, Congo, Eritrea, Indonesia, Rwanda, Myanmar and Niger during a strong El Nino in 1997.T

The study was published in Wednesday's Nature, scientists from Princeton University and Columbia University's Earth Institute used statistics to link global weather observations and outbreaks of violence. 

The scientists correlated ENSO from 1950 to 2004 with onsets of civil conflicts that killed more than 25 people in a given year. The data included 175 countries and 234 conflicts, with over half of which each caused more than 1,000 battle-related deaths.

The findings suggest that the arrival of El Nino doubled the risk of civil conflict across 90 affected tropical countries, and may help account for a fifth of worldwide conflicts over the past half-century. 

Links were found between El Nino patterns and civil unrest in Peru in 1982 and Sudan in 1963.

Further, a strong link between violence and El Nino were also found in El Salvador, the Philippines and Uganda in 1972, Angola, Haiti and Myanmar in 1991, and Congo, Eritrea, Indonesia and Rwanda in 1997.

Exceptions were found in Australia who was impacted majorly by El Nino but did not get into any major conflicts.

We're not trying to explain all the conflicts in the world. What we are trying to show is that the global climate does play a major role where previously people didn't believe that, said lead author Solomon Hsiang, an international affairs and environmental policy researcher at Princeton University.

El Nino patterns can be predicted up to two years ahead, the study may give room for pre-emptive action for some conflicts and reduce humanitarian suffering.