There is a growing and important recognition of the health implications of global climate change within the field of public health. Abundant evidence of this is available at both the national and international levels, but here let me mention some of the recent resources and activities of APHA. For example, APHA has been conducting a webinar series on the health implications of climate change and the public health response. In addition, there are two important new documents — Conveying the Human Implications of Climate Change and Climate Change: Mastering the Public Health Role, A Practical Guidebook. (Information about the webinars and both of these documents are available at www.apha-environment.org).

Unfortunately, there is an influential discourse of climate change denial in the United States. The fact of the matter is that this is an ideological discourse, not a scientific one; and it is promoted by those with a vested interest in carbon intensive technologies. The scientific evidence for excessive and increasing levels of green house gases in the atmosphere, the rapid melting of ice sheets and glaciers around the world, and measurable warming of the atmosphere in interaction with the conditions of the world’s oceans combine to present us with plethora of changes that will affect the health, the food and fresh water supply, and the quality of life of people throughout the world.

This truth is certainly “inconvenient,” to use Al Gore’s memorable phrase, but it is more than that, it is frightening and alarmingly urgent. The human and ecosystem costs of climate change are upon us now, and those costs and challenges will be probably the single most significant background condition of political, economic and personal life for generations to come.

Today’s public health agenda is rich and crowded, to be sure. Global health justice and disease prevention is enormously important. Promoting health and human rights by getting at the underlying social determinants of health and the health inequities and disparities around the world is enormously important. The aging demographics of many countries (which is the fruit of public health’s twentieth century successes) and the crisis of long term care and disability in virtually all countries of the world are enormously important.

But none of these challenges is more daunting in its implications than climate change; and indeed, I would argue, none can be understood or dealt with properly unless placed in the context of climate change.

The fields of environmental science that study climate change and the fields of public health that study social epidemiology and policy contain the same lesson and message: No organism (including human beings) exists as a separate, self-contained biological unit. All biological functioning (and dysfunction) is embedded in a context of natural and social systems. When we talk of “environmental health,” we can no longer attend only to a pollution model in which we simply see the environment as a source of pathogens or toxins affecting human disease. To supplement that perspective, there is a growing awareness that we must understand ecosystems as webs of life that are the ground and the fundamental infrastructure of human health and flourishing.

Climate change and public health perspectives converge in another way, as well. Both fields are underscoring the vital importance of recognizing vulnerability, resiliency and social justice.

That is where climate change becomes especially relevant to the public health needs of the elderly and to public health policy in an aging society. As people age, they generally become less directly and personally involved in those activities that create the largest carbon footprints. Despite some silly stereotypes, most retirees do not jump into their gas-guzzling recreational vehicles and tour the country. Aging in place and new forms of congregate residential and support facilities are patterns much more conducive to personal well-being, community cohesion and environmental sustainability. (There is a huge infrastructure to be built in the coming decades to house the elderly boomers, and it no doubt will be constructed in much greener ways than current housing was.)

The problem arises because it is precisely the life circumstances and the health needs of the elderly that make them most susceptible to the various manifestations of climate change. In the United States significant risks are posed by extreme weather events such as long, severe heat waves, and violent storms that cause flooding or severe blizzards. As these situations become more intense and frequent, as climate change scientists expect they will, those with underlying health conditions, low-income groups, and those with various types of disability will be an increased risk. Extreme weather events often require evacuation, or else they confine people to their homes without adequate access to necessities for prolonged periods of time. They also routinely lead to breakdown of our social infrastructure and support services, such as loss of electricity, communications and emergency response services. One recalls the crisis and loss of life in flooded neighborhoods and at medical facilities and nursing homes in the New Orleans area in the aftermath of hurricane Katrina. This profile of climate change induced stress and disruption is bad news for the elderly.

At least two lessons grow out of these sobering considerations.

First, climate change adaptation planning and public health emergency preparedness planning must be coordinated and go hand-in-hand. Better synthesis is beginning to happen, but too often in the past these two types of community awareness and preparation were proceeding in isolation from one another. In these activities, it is essential that the special needs of vulnerable populations, including the elderly, be represented and provided for. Climate change is detrimental to everyone, but it will be more detrimental to some than to others. Seniors are not without resources and resiliency of their own, but they will need well informed plans and targeted resources, which may not be forthcoming if their voices are not heard and if they are not present at the planning table.

The second lesson concerns ethics and responsibility. Climate change is often portrayed as a distant problem for a future time and the next generation. Seniors may well ask, should I worry about that? The obvious answer is that the elderly should care about climate change because its effects are already upon us, and they are going to be at risk during the remaining years of their own lives. A more interesting response takes note of the fact that many of today’s elderly have grown up and lived through times of common struggle and hardship. It is not characteristic of their generation to be exclusively focused on narrow self-interest, a “what’s in it for me” attitude. The elderly are the custodians of the future, not in the sense that they will make the future, but in the sense that they tend to be the principal trustees of the values that protect the future. Time and time again, they show themselves to be identified with issues they perceive to be important, not primarily to themselves, but to their children and their grandchildren.

The challenges of climate change are not merely threats to elderly. These challenges are also a call to the elderly — a call to step up on behalf of the generations to come, a call to draw upon the wisdom and experience of their own lives so as to shape their own legacy.

Bruce Jennings is Director of Bioethics at the Center for Humans and Nature and is a lecturer at the Yale School of Public Health. He is currently the chair of the APHA Ethics SPIG.