We know that climate change imperils coastal communities around the world and endangers food and water sources, and that political and religious extremism feed off instability and cause bloodshed. But because each contributes to the other, the future of millions may be at risk.
A 2013 University of California–Berkeley study analyzed 60 previous studies and concluded that the connection between climate change and human conflict is strong. Droughts and famines, floods, wildfires, and other events caused at least in part by climate change lead to instability that extremist groups can take advantage of to create conflict.
A more recent report by CNA, a research non-profit with national-security expertise, focuses on the connection between water stress and conflict. "Water stress can empower violent extremist organizations and place stable governments at risk," the authors write. Some experts believe we are heading toward a point where water will be more difficult to come by and brutal wars will be fought over control of fresh-water resources.
Sherri Goodman, a senior fellow at the Woodrow Wilson International Center and the United States' former deputy undersecretary of defense for environmental security, coined the term "threat multiplier" to describe how climate change accelerates security risks. She said water stress is a source of instability around the globe. "When there is a shortage or scarcity of water, it can be used to make people vulnerable and can be used by combatants, terrorists, or others to put innocents in precarious positions for exploitation, to force migration, and to target vulnerable populations," Goodman said. "You can see that that's happened now in Yemen. You can see the patterns of prolonged drought in Syria, which forced migration." Where else could climate change prove especially destabilizing? Experts say the cities below are among those most at risk of climate-related conflict. The good news is that at least two of them are taking measures to prevent it.
If you've been following the global news, you know that taps may be turned off completely in Cape Town, South Africa, in coming months because of water scarcity. (However, officials recently announced that "Day Zero" may be averted, thanks to conservation measures in place now.) If taps are shut off, residents will have to go to collection points in the city to get water, and the army and police would be deployed to maintain order. Residents are bracing for "chaos." Violence could flare, Goodman said.
Mismanagement of resources and unsustainable development have been blamed for the water crisis in Cape Town. Though climate experts warned of a looming water shortage literally for decades, city officials continued to approve commercial developments that drained water resources and allowed rich residents to consume more than their fair share of the water supply.
This is the city's worst drought in over a century, so it's possible that running out of water may have been unavoidable. But it's clear this disaster could have, at minimum, been delayed with better resource management.
In some parts of Pakistan's largest city, taps have run dry for extended periods of time, and the water drawn from wells is too salty to drink. According to Karachi's water utility, a full 42 percent of the municipal water supply is either lost to leakage or stolen. Water thieves siphon it off to sell to thirsty residents.
Neil Bhatiya, a research associate at the Center for a New American Security, a think tank, pointed to Karachi as an example of the nexus between climate change and conflict. India and Pakistan share water sources and have, Bhatiya said, a "contentious" relationship when it comes to water management (among other issues).
"Pakistan has a pretty well documented link between rhetoric around resource scarcity—in particular, water—and a lot of the anti-Indian terrorists that operate out of either Kashmir or Pakistan itself," Bhatiya said. "It's something extremist groups have used as a recruiting tool."
Protests are already frequent on Karachi's streets and often turn violent. With its population growing fast, demand for water—and for food crops that need water—will rise too. Meanwhile, the Indus River, the source of most of Pakistan's water, is supplying less than it did 50 years ago. Some of the newcomers swelling Karachi's population of 15 million are climate migrants, who have left rural areas due to extreme heat, drought, or flooding. If their numbers increase, so will competition for resources.
Meanwhile, the city on the Arabian Sea is at high risk from rising sea levels, which could displace many residents in coming decades.
Bangladesh's largest city faces problems related to sea-level rise, water and food shortages, overpopulation, and other risks. But the country is also a renewable energy model. The national-government-sponsored company Idcol has installed small solar systems in millions of homes across the country, and a solar plant now supplies electricity to the national grid. Dhaka's climate-resilience initiatives include improving trash collection to keep drains clear and promoting green roofs to offset the urban heat-island effect and soak up stormwater.
"In [Dhaka's] poor neighborhoods, communities are training emergency response volunteers, installing solar panels, starting community savings schemes and providing job training," according to a report from the Thomson Reuters Foundation.
"Of all of the governments of the developing world, I think Bangladesh is the one that has been fairly good about articulating the nature of the crisis and placing it within a larger political and diplomatic context," Bhatiya said.
Political instability in the country threatens its ability to respond to disasters. But Goodman said many national officials see the connection between climate issues and conflict and want to make sure citizens aren't taken advantage of by extremist groups. "Extremists thrive on conditions of vulnerability, where people can't provide for themselves and their families," she said.
As Typhoon Haiyan tragically showed in 2013, the island nation of the Philippines is among the countries that are most exposed to natural hazards. It is also at high risk from climate change. (See this map for a region-by-region breakdown.)
"Heat stress, extreme precipitation, inland and coastal flooding, as well as drought and water scarcity pose risks" to Manila and other tropical and sub-tropical coastal cities, according to the Intergovernmental Panel on Climate Change. Coastal areas of Metro Manila are "faced with the possibility of having ... huge portions of their communities submerged." Last September, torrential rains led to a landslide that killed two people outside of the city.
As part of the Paris Agreement, the Philippines pledged to meet a 70 percent reduction of climate emissions by 2030. Back in 2009, it created a national climate-change commission, which runs adaptation and mitigation initiatives. President Rodrigo Duterte's stance on climate change has fluctuated, but a $500 million flood-control system for Metro Manila—part of the president's "golden age of infrastructure"—is set to begin construction soon.
Terrorist groups including Abu Sayyaf and ISIS are active in the Philippines, and radicalization could thrive in the uncertainty and hardship following a major disaster. Goodman said that, arguably, the country's proactive measures on climate change could help it avoid a major increase in conflict.
Because climate change and conflict are so inextricably tied, efforts to make a city more sustainable often double as increasing stability and security. Cities that prepare may be able avoid a breakdown of order. But cities that fail to act could come apart at the seams.