Social and political tensions fuelled by climate change have yet to translate into international military confrontations, but local conflicts are heating up due to pressures such as drought and water scarcity, officials and researchers said on Wednesday, Thomson Reuters Foundation reports.
In fragile states like Yemen and South Sudan, competition for scarce natural resources is increasing while a growing need for humanitarian aid undermines states' ability to deal with climate risks, said Johan Schaar of the Stockholm International Peace Research Institute.
"I don't see big, shooting wars but I think you will have an increasing frequency of very localised conflicts and tensions that could then escalate into much more," Schaar told the Thomson Reuters Foundation at World Water Week in Stockholm.
Climate-related disasters often force people from their homes, putting a strain on the communities into which they move and stirring grievances, he added.
In South Sudan, the world's newest country, climate change is shortening and delaying the rainy season, while almost 80% of the rural population is affected by droughts and floods, said Alier Oka, undersecretary at the Ministry of Water Resources and Irrigation.
"Climate change has impacted resources. Rainfall variability is the key issue," he told the conference.
That is pushing some herders to consider moving to new areas in search of pasture and water, where they are likely to run into problems with settled farmers.
"This is common in South Sudan and happening now," he said.
As a result, looting of cattle and tribal fighting are occurring more frequently, he added.
War or peace?
In Yemen, embroiled in a bloody civil war since 2015, water has become "weaponised", said Muna Luqman, chair of Food4Humanity, a local charity.
Half the population has no access to safe drinking water, which was already a scarce commodity in the parched Middle Eastern country before conflict broke out, she said.
Now both sides have targeted the resource as a tool of war, she added.
A lack of laws to regulate water use, combined with climate stresses such as drought and extreme heat, has worsened health and social problems with women and children worst-hit, she said.
"(Fighters) speak about freedom and human rights… while they kill and maim women fetching water for their starving families," she said.
Yemen is suffering its third major cholera outbreak since 2015, when a Saudi-led military coalition intervened to try to restore Yemen's internationally recognised government after it was ousted from power by the Iran-aligned Houthi movement.
But using water wisely can foster peace, said Luqman, who has worked on projects to encourage tribes in remote areas to share water stations.
More than half the world's population is likely to live in water-scarce areas by 2050, according to the Economist Intelligence Unit, which launched a "Blue Peace" index earlier this month to better manage shared water supplies.
Elisabeth van Duin, a director at the Netherlands Ministry of Infrastructure and Water Management, warned that a lack of safe water, migration and population growth could all "destabilise societies and contribute to regional conflict".
From Syria to Lake Chad, climate change has escalated tensions, she said, with global hotspots in the future likely to include India and China, where millions of people are set to become victims of droughts and floods by 2050, she added.
"Water can become a weapon in conflict," she told the conference, adding that climate and water stress would be "particularly hard on the developing world".