The Public Health Implications of Global Warming

IN 1861 THE NATURAL PHILOSOPHER JOHN TYNDALL MADE THE PREDICtion, little noted at the time, that anthropogenic emissions of carbon dioxide would trap the radiative energy of the sun within the earth’s atmosphere and raise surface temperatures. An early investigation of this “greenhouse effect” concluded that a “large-scale geophysical experiment” began ever since the Industrial Revolution wed civilization to fossil fuels. The recent data of several international consortia show that global warming is accelerating at a rate far greater than that predicted a century ago and is due in large part to combustion of fossil fuels. This issue of MSJAMA brings together several lines of published evidence that global warming has emerged as a public health challenge requiring serious, concerted action. Jonathan Patz and Mahmooda Khaliq survey the immediate threats posed by climate change as well as some of the more insidious ones. Kent Bransford and Janet Lai find grounds for a common approach to both climate change and air pollution. Stephen Liang and colleagues describe technologies that can help track the spread of climate-sensitive infectious disease vectors. Finally, William Burns discusses public policy tools to respond and adapt to these challenges. Unfounded alarmism has no place either in clinical practice or in the legislative process. On the other hand, we cannot simply ignore extensive, peer-reviewed data on the causes and impacts of climate change. Lending a sense of urgency to this seemingly distant and abstract threat may well require us to link its consequences to our quality of life. In the absence of domestic leadership on global warming, one way to accomplish this goal might be to summon health care professionals to nontraditional advocacy roles. A similar approach helped give birth to the Montreal Protocol of 1987. Parties to the convention that produced the treaty identified depletion of the UV-absorbing ozone layer by chlorofluorocarbons (CFCs) as a public health threat of potentially catastrophic proportions requiring immediate action, namely, the phasing out of CFCs and related compounds. A role for health care professionals in global environmental policy is a natural extension of a growing ethos of preventive medicine, the sort that has, for instance, reduced the prevalence of smoking in the United States and led to improvements in food, highway, and gun safety. Similarly, it is not too late and none too soon for the health care community to advocate policies that wean us from fossil fuels and ultimately mitigate the extent of human-induced climate change.