This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Natural Hazard Science. Please check back later for the full article.
Increasingly frequent and intense extreme climatic events are wreaking havoc in regions all over the world, not only causing immediate death and destruction, but also destroying prospects for attaining the most basic of human needs—water, food, and secure shelter. What is more, the problems brought about by extreme events are often exacerbated by ecosystem destruction due to human activities. This is a universal, global problem. Children are the most vulnerable. Insufficient and polluted water afflicts a third or more of the people of the world causing over a billion illnesses, illnesses often related to 2.5 billion people lacking sanitation, and illnesses often combined with malnutrition. In 2013, 783 million people lacked clean water. Procurement and allocation of water are major problems in rural and urban areas. More than 70% of fresh water is used for irrigation of crops, much of it lost to evaporation, and much resulting in build up of salinization on bordering farmland. Cities, now home to 54% of the world’s population, often lack adequate infrastructure to provide clean drinking water. In the United States, cities are faced with contaminated water from their pipes, as in Flint Michigan and in New Jersey schools. Naturally occurring water pollutants that can harm ecosystems, aquatic organisms, and humans are becoming more prevalent due to physical developments and climate change. For example, toxic cyanobacteria, also known as blue-green algae, in coastal and inland waters are causing mortality and morbidity in humans, livestock, and wild animals. Over the last three decades, one of these bacteria, C. raciborskii has been increasingly recognized as a public health exigency for drinking water supplies across all inhabited continents.
While food today is more readily available worldwide than in the past, nearly a billion people go hungry. The roughly billion people who rely on fish from the oceans are faced with dwindling harvests due to overfishing, warming waters that harm coral reef breeding grounds, and the loss of mangrove spawning grounds. Crops and livestock are hurt by climate change. Productivity is diminished by reliance on monoculture, poor storage, and transportation problems. The situation is drastically worsened by unnecessary waste and spoilage. The world is producing more than enough food, according to the Food and Agriculture Organization of the United Nations, which says that “Recovering just half of what is lost or wasted” alone could feed the world. Regarding spoilage, aflatoxins—poisonous, cancer-causing chemicals produced by certain molds—are found in spoiled food, including staples such as corn, millet, peanuts, and wheat, affecting not only immediate consumers, but also those who buy processed food. Droughts causing dead livestock and wilted crops have driven millions from their homes and farmland, as happened in Syria. Subsequent conflict led millions of Syrians to become both political and climate refugees, living in refugee camps and traveling thousands of treacherous miles to resettle. Poverty, whether experienced in slums, refugee camps, or other rural and urban settings, causes lack of land and shortages of material for soundly built housing that can withstand weather changes, even screens to help reduce exposure to mosquitoes, flies, and other disease vectors. The nearly quarter of the world’s urban population who live in slums live mostly in overcrowded, unsafe shelters that lack structural security, water for drinking, cooking, and hygiene, and sanitation. They are exposed to communicable diseases and suffer mental stress. Community space, adequate education, and chances for employment or a way out of the slums are rare. In numerous coastal communities, houses are endangered by extreme weather conditions exasperated by climate change. The sea’s rise in India has caused river delta islands to vanish. In 2016, the first climate refugees in the United States, an entire community of Native American Indians, are being forced to move from their ancestral homes on Isle de Jean Charles, Louisiana. The present challenges are aggravated by climate change, population growth, and forced migration. It is critical to focus on these basic, inextricably interlocked needs for water, food, and secure shelter, with a view to preventive measures, and to do so with extreme sensitivity to cultures, communities, ecosystems, and ramifications to human health.