The average country score improved by 0.09 per cent, with 86 countries getting better and 76 deteriorating.
India's rank has slipped five places to 141 among 163 countries on the Global Peace Index 2019, while Iceland remains the most peaceful country and Afghanistan the least peaceful nation, says a report.
The index assigns each country a score between one and five, where one is the most peaceful and five is the least, based on 23 indicators ranging from homicide levels to weapons imports.
The 2019 report also includes new research on the possible effects of climate change on peace, the statement said.
Almost a billion people live in areas of high climate hazard and about 40% of them are in countries already struggling with conflict, according to the IEP.
More than 400 million people live in areas with low levels of peacefulness and high risk from climate change.
South Africa's ranking: 127 (down 2) in the world, 32 in Sub-Saharan Africa.
"Pacific Islands are going to be massively impacted by rising sea levels", Mr Killelea said, adding that they would be the first affected due to their proximity to the equator.
Countries with very high levels of peace, on average, achieved over three times higher per capita GDP growth compared to the least peaceful countries for the last 60 years.
Iceland remains the most peaceful country in the world, a position it has held since 2008, the Institute for Economics and Peace (IEP) said in a statement. Bhutan has recorded the largest improvement of any country in the top 20, rising 43 places in the last 12 years, it added.
Climate change poses a threat to peace in countries around the world in the coming decade, according to an annual peace index released today that factored in the risk from global warming for the first time.
Ghana, Mauritius, Botswana, Malawi and Zambia were the region's most peaceful countries, while Nigeria, Democratic Republic of Congo, Central African Republic, Somalia and South Sudan recorded lowest levels of peacefulness.
"The main drivers have been a slowing down of the conflict in Syria and there has been fall in number of deaths from internal conflict".
The region experienced a reduction in population displacement, political terror, deaths from internal and external armed conflicts, terrorism, military spending and armed services personnel - all which contributed to the region's improvement.
But while conflicts and crises that emerged in the past decade have begun to abate, new tensions within and between nations have emerged, the report finds.
The one thing that the countries at the very top of the index all had in common, according to Mr Killelea, were well functioning governments and good business environments, which were easier to maintain once they had initially been established.
On the other hand, positive peace does not mean only the absence of violence, but a presence of justice, institutions and structures preventing it.