Globalization, Climate Change, and Human Health

he global scale, interconnectedness, and economic intensity of contemporary human activity are historically unprecedented, 1 as are many of the consequent environmental and social changes.These global changes fundamentally influence patterns of human health, international health care, and public health activities. 2 They constitute a syndrome, not a set of separate changes, that reflects the interrelated pressures, stresses, and tensions arising from an overly large world population, the pervasive and increasingly systemic environmental impact of many economic activities, urbanization, the spread of consumerism, and the widening gap between rich and poor both within and between countries.In recent decades, international connectivity has increased on many fronts, including the flow of information, movements of people, trading patterns, the flow of capital, regulatory systems, and cultural diffusion.These exponential increases in demographic, economic, commercial, and environmental indexes have been labeled the Great Acceleration.3 Remarkably, the resultant environmental effects are now altering major components of the Earth system.4,5 The current geologic epoch is being called the Anthropocene (successor to the Holocene epoch) 5,6 in recognition of the global force that Homo sapiens has become, pushing or distorting Earth’s great natural global systems beyond boundaries considered to be safe for continued human social and biologic well-being.4,7 The loss of biodiversity, the greatly amplified global circulation of bioactive nitrogen compounds, and humaninduced climate change have already reached levels that are apparently unsafe.4 These changes pose fundamental threats to human well-being and health.4,7 For example, a positive relationship has been observed between regional trends in climate (rising temperatures and declining rainfall) and childhood stunting in Kenya since 1975, indicating that as projected warming and drying continue to occur along with population growth, food yields and nutritional health will be impaired.8 These human-induced climatic changes often act in concert with environmental, demographic, and social stressors that variously influence regional food yields, nutrition, and health.Furthermore, at the current level of global connectedness and interdependence, the environmental impact of human activity has a wider geographic range, although its influence may be offset somewhat by more effective global alerts and more rapid distribution of food aid.The extreme heat and wildfires in western Russia in the summer of 2010 destroyed one third of that country’s wheat yield, and the subsequent ban on exported grain contributed to a rise in the price of wheat worldwide, exacerbating hunger in Russia (where flour prices increased by 20%) and in low-income urban populations in countries such as Pakistan and Egypt.9,10 On the economic front, the recent global financial crisis has underscored the domino-like interdependence of national economies.