Rising Global Temperatures Linked to Rising Violence
August 2, 2013
The Los Angles Times & The National Geographic & International Institute for Sustainable Development
Long before scientists began to study global warming, author Raymond Chandler described the violent effects of dry, "oven-hot" Santa Ana winds gusting through the city of Los Angeles. Now UC Berkeley researchers and other scientists have reviewed data on ancient wars, road rage and more and reached the frightening conclusion that violence may increase between now and 2050 because of higher temperatures and extreme rainfall patterns.
Violence Will Rise as Climate Changes, Scientists Predict
Monte Morin / The Los Angles Times
(August 1, 2013) -- Long before scientists began to study global warming, author Raymond Chandler described the violent effects of dry, "oven-hot" Santa Ana winds gusting through the city of Los Angeles.
"Every booze party ends in a fight," he wrote in his 1938 story "Red Wind." "Meek little wives feel the edge of the carving knife and study their husband's necks. Anything can happen."
While social commentators have long suggested that extreme heat can unleash the beast in man, formal study of the so-called heat hypothesis -- the theory that high temperatures fuel aggressive and violent behavior -- is relatively new. Using examples as disparate as road rage, ancient wars and Major League Baseball, scientists have taken early steps to quantify the potential influence of climate warming on human conflict.
Now, three UC Berkeley researchers have pulled together data from these and other studies and concluded that the incidence of war and civil unrest may increase by as much as 56% between now and 2050, due to warmer temperature and extreme rainfall patterns predicted by climate change scientists.
Likewise, episodes of interpersonal violence -- murder, assault, rape, domestic abuse -- could increase by as much as 16%, they report in a study published Thursday by the journal Science.
"We find strong causal evidence linking climatic events to human conflict ... across all major regions of the world," the researchers concluded.
The study assumes a global temperature increase of at least 4 degrees Fahrenheit over the next half-century, based on data from the World Climate Research Program in Geneva. It also assumes that humanity will do little to adapt to large changes in regional climate or altered rain patterns, such as developing new heat and drought-tolerant crops.
With those ground rules established, the team examined 60 papers across a variety of fields -- including climatology, archaeology, economics, political science and psychology -- and analyzed them against a common statistical framework.
Study topics ranged from the trivial to the sublime.
In one paper, researchers held up traffic at a sweltering Phoenix intersection to see whether motorists in cars without air conditioning were more likely to honk in anger than drivers in climate-controlled vehicles. In another, psychologists looked at weather records and Major League Baseball statistics to see whether pitchers were more likely to throw bean balls at opposing batters as the mercury rose.
Still others used data from tree rings in Southeast Asia to gauge the influence of severe drought on the collapse of the once-mighty Angkor kingdom, or analyzed sediment from Middle Eastern seas to determine how desertification influenced the fall of the Akkadian Empire more than 4,000 years ago.
No matter where in the world they looked, and no matter what time period, the researchers said they observed a link between temperature, precipitation and conflict. They calculated that large-scale group conflict could increase between 28% and 56% over the next 37 years, while interpersonal violence could increase between 8% and 16%.
"The result is alarming," said study coauthor Marshall Burke, a UC Berkeley graduate student who specializes in how climate change affects food security. "However, if we get our act together and we mitigate future climate change ... the effects will be much smaller."
The authors say they can only speculate on the reasons why increased temperature and changed patterns of rainfall would move humans to violence.
"The physiological mechanism linking temperature to aggression remains unknown," they wrote.
One traditional explanation is that climate shifts hit agrarian economies particularly hard. "People are more likely to take up arms when the economy deteriorates," said study leader Solomon Hsiang, who examines the policy consequences of climate change at UC Berkeley.
Hsiang and his colleagues make no attempt to establish a clear cause, though they say there might be a physiological link between heat and aggression. But they are not biologists; their intent, they say, is to spur further research and encourage adaptive planning in the face of global warming.
"We like to compare it to smoking," Burke said. "In the 1930s scientists were figuring out there was this really strong relationship between smoking and lung cancer, but it wasn't for many decades after that they figured out the precise mechanism that links smoking to lung cancer."
Researchers who weren't involved in the analysis praised the team for their ambitious attempt to synthesize data from a variety of studies in disparate fields.
The paper "presents a strong case for the effects of rapid climate change on violence," said Craig A. Anderson, an Iowa State psychology professor who studies violence. "There is considerable evidence that when people are uncomfortably hot, they become more physically aggressive. They tend to interpret minor annoyances as being more serious and intentional provocations than they would in comfortable temperatures."
Yet others said the paper fell short of its intended goal.
"The study does not give a single example of a real conflict where both data and qualitative evidence suggest that the violence was caused at least partly by climatic anomalies," said Halvard Buhaug, a professor of political science at the Peace Research Institute Oslo in Norway.
An accompanying editorial by Science Editor in Chief Marcia McNutt, a geophysicist, did not address the study specifically, but instead called on scientists from different fields to help study the cumulative impacts of climate change.
"There is a need for all scientists to rise to this challenge," she wrote.
Copyright 2013, Los Angeles Times
Wars, Murders to Rise Due to Global Warming?
Shifts in temperature and rainfall linked to more aggression, study says
Ker Than / The National Geographic
(August 1, 2013) -- Wars, murders, and other acts of violence will likely become more commonplace in coming decades as the effects of global warming cause tempers to flare worldwide, a comprehensive new study warns.
The research, detailed in this week's issue of the journal Science, synthesizes findings scattered across diverse fields ranging from archaeology to economics to paint a clearer picture of how global warming-related shifts in temperature and rainfall could fuel acts of aggression.
Though scientists don't know exactly why global warming increases violence, the findings suggest that it's another major fallout of human-made climate change, in addition to rising sea levels and increased heat waves.
"This study shows that the value of reducing [greenhouse gas] emissions is actually higher than we previously thought," said study first author Solomon Hsiang, an economist at Princeton University in New Jersey. (Related: "Global Warming Making People More Aggressive?")
Leveling the Field
To perform their analysis, Hsiang and his colleagues sifted through hundreds of studies published across a number of fields, including climatology, archaeology, economics, political science, and psychology.
"[As economists], we were way out of our comfort zone," Hsiang said. "It's been quite an interesting experience. I've never done anything like this before."
The team eventually settled on 60 studies on subjects related to climate, conflict, temperature, violence, crime, and more, and reanalyzed those studies' data using a common statistical framework. An analogy would be converting currencies from different European countries into the euro so that meaningful comparisons could be made.
They did this to account for the fact that different parts of the world experience different variabilities in temperature and rainfall. For example, an increase of 2°F (1.1°C) might not be a big deal in the United States, where temperatures can vary widely, but it might be unusual for a country in Africa.
When the team converted the data and compared them, the results were striking: They found that even relatively minor departures from normal temperatures or rainfall amounts substantially increased the risk of conflict on a variety of levels, ranging from individual aggression, such as murder and rape, to country-level political instability and international wars.
The study data covered all major regions of the world and different time spans as well, from hours and years to decades and centuries. Across the data, the researchers found similar patterns of human aggression fueled by climate factors.
Examples included spikes in domestic violence in India and Australia, increased assaults and murders in the United States and Tanzania, ethnic violence in Europe and South Asia, land invasions in Brazil, and police using force in the Netherlands.
The effect wasn't limited to just modern societies, either. Among the research Hsiang and his team looked at was a study that linked increased political instability and warfare in the ancient Maya civilization around A.D. 900 to prolonged droughts brought about by global warming-related climate shifts in lands near the Pacific Ocean. (Related: "Why the Maya Fell: Climate Change, Conflict—And a Trip to the Beach?")
"That's when the classical period of Mayan civilization ends," said study co-author Edward Miguel, a professor of economics at the University of California, Berkeley.
Another study linked the 14th-century collapse of Cambodia's ancient Khmer civilization, which built the temple of Angkor Wat, to decades of drought interspersed with intense monsoon rains.
"Archaeologists can actually observe how [Khmer] engineers were trying to adapt," Hsiang said. "They were trying to keep up with the climatic changes, but in the end, even though they were the most sophisticated water engineers in the region at the time, it still seemed too much."
Hsiang says his team included these historic case studies in their analysis in order to understand how populations adapted—or didn't—to the kinds of gradual climate changes that climatologists predict for the future. But he thinks there are also lessons to be learned from the past.
"A lot of the civilizations that were nailed by climatic shifts were the most advanced societies in their region or on the planet during their day, and they probably felt they could cope with anything," he said.
"I think we should have some humility [and] recognize that people in the past were very innovative and they were trying to adapt to these changes as well."
Why Does Warming Make People Mad?
Brad Bushman, a professor of communication and psychology at Ohio State University who specializes in human aggression and violence, called the study "impressive."
"The convergence of findings across so many different disciplines increases your confidence that you've got a pretty reliable effect here," said Bushman, who was not involved in the research.
"Hopefully, this study will increase awareness that climate change spans many different domains of human activity, including conflict." (See "6 Ways Climate Change Will Affect You.")
While the new study helps strengthens the case for climate change influencing human aggression, it was not designed to address the question of why it does.
Other scientists have speculated on possible mechanisms. For example, Bushman thinks dramatic changes in temperature and rainfall are unpleasant and naturally make people more cranky. "When people are in a cranky mood, they're more likely to behave aggressively," he said.
Another theory is that too much or too little rain can negatively affect a country's agriculture and lead to economic ruin.
"When individuals have very low income or the economy of the region collapses, that changes people's incentives to take part in various activities," study first author Hsiang said. And "one activity they could take part in is joining a militant group."
The team thinks researchers will eventually discover that multiple mechanisms are at play simultaneously.
Hsiang compared modern scientists studying the relationship between climate and aggression to medical doctors in the 1930s who knew that smoking and lung cancer were linked but had not yet uncovered the mechanism.
"It took decades, but people did eventually figure out what was going on, and that helped us design policies and institutions to help mitigate the harmful effects [of smoking]," Hsiang said.
Similarly, co-author Miguel said, pinning down the mechanisms behind how global warming affects aggression will be the "next key frontier" for this area of research.
Rising Temperatures, Rising Tensions
Climate change and the risk of violent conflict in the Middle East
Oli Brown and Alec Crawford / International Institute for Sustainable Development (IISD)
The Levant -- made up of Syria, Lebanon, Israel, Jordan and the occupied Palestinian territory (oPt) -- has experienced more than 60 years of bloody conflict. Despite some brief interludes of optimism in the early 1990s, the history of conflict and mistrust between and within the countries, the ongoing occupation of Palestinian territory and the Golan Heights, and periodic hostilities mean that a durable peace in the region remains a distant prospect.
Against this backdrop, the mounting scientific evidence confirming the speed and scope of climate change seems, at most, a secondary concern to be addressed once other problems have been resolved. However, climate change -- by redrawing the maps of water availability, food security, disease prevalence, population distribution and coastal boundaries -- may hold serious implications for regional security. Hotter, drier and less predictable.
In a region already considered the world’s most water-scarce and where, in many places, demand for water already outstrips supply, climate models are predicting a hotter, drier and less predictable climate. Higher temperatures and less rainfall will reduce the flow of rivers and streams, slow the rate at which aquifers recharge, progressively raise sea levels and make the entire region more arid.
These changes will have a series of effects, particularly for agriculture and water management. Under moderate temperature increases, for example, some analysts anticipate that the Euphrates River could shrink by 30 per cent and the Jordan River by 80 per cent by the end of the century.
This report, prepared by an independent Canadian environment and development research institute, seeks to present a neutral analysis of the security threat of climate change in the region over the next 40 years (to 2050), drawn from consultations and extensive interviews with experts from across the region’s political and ethnic divides. The report presents the following conclusions:
• The legacy of conflict undermines the ability of the region to adapt to climate change More than 60 years of conflict have taken a heavy toll on the region’s ability to cope with climate change.
Sometimes this is tangible, manifested through the physical destruction of infrastructure, the loss of forest and water resources, the expense of maintaining large standing armies, or a lack of statehood, which complicates participation in international processes. At other times, it is more insidious, revealing itself through a steady reduction in economic opportunity, an unwillingness to cooperate over water and energy projects, or the emergence of an ‘island mentality’ approach to resources.
This legacy greatly complicates efforts to collaborate over shared resources, to invest in more efficient water and energy use, to share new ways to adapt to climate change and to pursue truly multilateral action on climate change. Ultimately, it means that climate change likely presents an even more serious challenge than it would otherwise.
• Climate change poses some very real security concerns Security is a constant concern in the Levant.
However, the security threat of climate change is rarely discussed. Public and political attention tends to focus, understandably, on the many immediate dangers that trouble the region. This is beginning to change with the growing realization among regional analysts that climate change may present a real threat to security.
The Levant already struggles with scarce water, food insecurity and erratic economic growth, each of which could be exacerbated by climate change. This report argues that climate change present a security threat in six distinct ways:
THREAT 1-- Climate change may increase competition for scarce water resources, complicating peace agreements: The impact of increased water scarcity as a result of climate change may make some existing peace agreements untenable, could complicate the negotiation of new peace agreements and could be a factor in national instability.
THREAT 2 -- Climate change may intensify food insecurity, thereby raising the stakes for the return or Rising Temperatures, Rising Tensions THREAT 4 – Climate change may lead to destabilizing forced migration and increased tensions over existing refugee populations:
Shifting rainfall patterns, spreading desertification and falling agricultural productivity are likely to undermine rural livelihoods, worsen job prospects in rural areas and accelerate migration to urban areas. This could strain services in cities and lead to increased resentment of existing refugee populations.
THREAT 5 -- Perceptions of resources shrinking as a result of climate change could increase the militarization of strategic natural resources:
The allocations of resources (falling in absolute terms as a result of climate change and in relative terms as a result of population growth and increased demand) could become increasingly tense. Control over them may become perceived as an increasingly key dimension of national security, and resource scarcity could be a pretext for their greater militarization.
THREAT 6 -- Inaction on climate change may lead to growing resentment and distrust of the West (and Israel) by Arab nations:
If the international community is unable to come to a deal in Copenhagen that shows a commitment to mitigate the effects of climate change and to help poorer countries adapt to its impacts, it may reinforce the already pervasive sense in the Arab world that many countries in West (including Israel) are not acting as ‘good global citizens’.
• There are ways to pursue peace and sustainable development despite a changing climate.
The evolving impacts of climate change will shape the progress and prospects of the region. It is possible that climate change, a shared threat like no other, may encourage countries to work together despite their political and ideological differences, to tackle the common challenge. In so doing climate change could become a vehicle for rapprochement and peacebuilding.
However, given the current political landscape, which continues to be characterized by distrust, hostility and a lack of cooperation, climate change is more likely to become an obstacle to peace. Indeed it could aggravate tensions in a number of serious ways.
But it is important not to overstate the case. Climate change will not be the only factor in future conflict, just as is not the only factor in the changing availability of water resources. Ultimately the wider political situation will determine whether scarce resources or forced migration becomes a cause of conflict or a reason for better cooperation.
The challenges of climate change and security in the Middle East are daunting. Action on climate change will, of course, only ever be a small part of the whole picture. Nevertheless, there is much that national governments and authorities, civil society and the international community can do to combat climate change, adapt to its impacts, manage increasingly scarce resources and foster greater cooperation on their shared resources.
With this in mind, the report concludes with four broad strategies for action: Strategy 1 Fostering a culture of conservation Raising awareness on climate change may help to encourage a culture of conservation and efficiency in the region. There are many gains to be had in terms of water and energy efficiency that could help offset the combined impact of growing demand, population growth and climate change.
Strategy 2 -- Adapting to the impacts of climate change Adaptation projects could address core tensions through better water management, agricultural development and disaster prevention. Community- level adaptation projects can help, in a modest way, to share skills and technologies and to build understanding between previously divided communities.
Strategy 3 -- Avoiding dangerous climate change Quite apart from the stand-alone rationale to reduce emissions of greenhouse gases, if Israel (as the largest per capita emitter in the Levant) and, to a lesser extent, the Arab nations were to take on commitments to tackle climate change it would be a powerful demonstration of global citizenship and solidarity.
Moreover, increasing energy efficiency and moving to renewable sources of energy generation would have important economic benefits for this energy-poor region.
Strategy 4 -- Enabling regional cooperation and international engagement.
Clearly, the challenge of climate change is one that is beyond the capacity of any one country to tackle. Its shared security implications will be best resolved through cooperation: to reduce greenhouse gas emissions; to develop comprehensive international strategies to manage forced m igration; to share the most innovative approaches for adaptation; and to manage shared resources, retention of occupied land:
Climate change could further decrease local agricultural productivity and make global food prices increasingly volatile, further politicizing the issue of food security.
As populations and demand for food grow, this could further increase domestic pressure for Syria or the Palestinian Authority to secure the return of occupied lands and shift the strategic calculations in Israel on whether to withdraw from these areas.
THREAT 3 -- Climate change may hinder economic growth, thereby worsening poverty and social instability:
The combination of higher unemployment, reduced government revenue and increased demands on services, as an indirect result of climate change, could weaken governments’ ability to provide services and create jobs, in turn potentially creating the conditions for extremism of all kinds, increased crime and social breakdown.
Posted in accordance with Title 17, Section 107, US Code, for noncommercial, educational purposes.