Climate change could result in "sudden and abrupt" shocks to countries around the world and have "far-reaching implications for global stability and security," a senior United Nations' official has warned.
Achim Steiner, executive director of the U.N. Environment Program, told the U.N. Security Council Wednesday that natural resources would be "at increasing risk from climate change and its impacts."
"There is a great deal of knowledge and analysis accumulated over many decades on the conditions and the triggers that can trip tensions and turmoil into conflict and war," he said.
"There can be little doubt today that climate change has potentially far-reaching implications for global stability and security in economic, social and environmental terms which will increasingly transcend the capacity of individual nation states to manage," Steiner added.
But he said there was "no reason" why the world could not avoid "escalating conflicts, tensions and insecurity related to a changing climate" if there was an effective response.
Steiner told the Security Council that climate change could potentially "sharply intensify" the displacement of people from some areas, "bringing communities into increasing competition for finite natural resources with world-wide repercussions for the stability of the global economy."
"Competition over scarce water and land, exacerbated by regional changes in climate, are already a key factor in local-level conflicts in Darfur, the Central African Republic, northern Kenya, and Chad, for example-when livelihoods are threatened by declining natural resources, people either innovate, flee or can be brought into conflict," he said.
"In total, 145 countries share one or more international river basins. Changes in water flows, amplified by climate change, could be a major source of tension between states, especially those that lack the capacity for co-management and cooperation," he added.
Steiner said it was difficult to say whether the severe drought in the Horn of Africa had ultimately been caused by greenhouse gases.
"There may be a climate change signature, but there is also natural variation and wider environmental change underway, such as deforestation, land degradation and over exploitation of other natural resources such as freshwaters," he said.
He pointed out that the world's population was nearly 7 billion and was expected to rise to more than 9 billion by 2050 "on a planet where resource constraints are rapidly emerging."
Steiner admitted that no one had "perfect knowledge on current or future climate change," but said humans had never planned ahead based on "100 per cent certainty."
He said the warming trend over the last 50 years of an average 0.13 degrees Celsius each decade was nearly twice that for the last 100 years and that a recent study suggested there would be a global sea-level rise of a meter or more by the end of the century.
"A one-meter rise in sea level could, for example, flood 17 per cent of Bangladesh's land area; threaten large parts of coastal cities such as Lagos, Cape Town and elsewhere and overwhelm, along with storm surges, small island developing States from the Maldives to Tuvalu," he added.
"In 2010, over 90 per cent of disaster displacement [of people] within countries was caused by climate-related hazards, primarily floods and storms," Steiner said. "Climate scenarios expect such weather events to increase and or intensify as a result of accelerating climate change."
He said climate change was giving new access to natural resources in the Arctic, highlighting "major untapped reserves of oil, gas and mineral."
Steiner also questioned whether "territorial sovereignty issues" might increase political tensions.