Implications of global climate change for violence in developed and developing countries.

apid global climate change, taking place over decades rather than millennia, is a fact of twenty-first century life. Human activity, especially the release of greenhouse gases, has initiated a general warming trend. The 10 warmest years on record between 1880 and 2008 were the last 10. This trend is expected to continue until the atmospheric composition returns to a preindustrial era norm. Climate change effects on specific regions are expected to vary considerably. Though most parts of the globe are warming, a few places may experience cooler climates as ocean and wind currents shift. Some regions are experiencing increased rainfall, whereas many others are having prolonged droughts. In 2007, the Intergovernmental Panel on Climate Change (IPCC) released a report that Included numerous projections of likely effects by the end of this century, under varying assumptions of how world governments, industries, and people respond. The best-case scenario assumes huge reductions in net greenhouse gas production, beginning almost immediately. In this scenario, climate models predict an average global temperature increase of 1.8°C (3.24°F) and an average sea level increase of 28 cm (11 inches). The worst-case scenario, which assumes a business-as-usual approach, predicts increases of 4.0°C (7.2°F) and 43 cm (17 inches). Other projections, some of which have already become apparent, include increases in heat waves and heavy precipitation; decreases in precipitation in subtropical areas; and increases in tropical cyclones. More specific projections include (1) 5-8% increase in the proportion of Africa that is arid and semiarid; (2) major flooding of heavily populated areas of Asia from rising sea levels and storms; (3) inundation of lowlying islands; (4) severe water shortages in Australia and New Zealand; (5) drought in southern Europe; (6) decreased soil moisture and food crops in Latin America; and (7) increased winter flooding and summer heat waves in North America. More recent research being prepared for the next IPCC report suggests that the new best-case scenario will be worse than the old worst-case scenario, with sea levels rising a least 1 meter (Vermeer & Rahmstorf, 2009). Because 13% of the world's population —hundreds of millions of people —live in low-lying coastal areas (Engelman, 2009, p. 41), this latter projection is particularly disturbing. Indonesia may lose as many as 2,000 small islands in the next 20 years to rising sea levels (Engelman, p. 3). In addition to the changes in average temperature and rainfall, climate models also predict an increase in extreme weather events. Recent data suggest that this increase has already begun, with dramatic increases in floods, wind storms, and drought disasters in the last 20 years (Engelman, 2009, pp. 16, 30). Hurricanes, cyclones, and other tropical storms also are increasing in intensity. The problem with rising sea levels concerns not just the height of high tides but also storm surge. A once-a-century storm in New York City, for example, will occur about once every 3 years (Rahmstorf, 2009) if average sea level increases by 1 meter. Research from psychology, sociology, political science, economics, history, and geography suggest that rapid global warming can increase the incidence of violent behavior in at least three ways. One involves direct effects of uncomfortably warm temperatures on irritability, aggression, and violence. A second involves indirect effects of global warming on factors that put children and adolescents at risk for developing into violence-prone adults. The third involves indirect effects of rapid climate change on populations whose livelihoods and survival are suddenly at risk, effects that influence economic and political stability, migration, and violent intergroup conflict. For example, various governmental and scientific reports have noted that climate change has exacerbated existing tensions and conflicts singled in the Darfur region of Sudan and in Bangladesh.