Much has been written about the economic impact of an aging population in which fewer workers exist to support retirees. Now, a new study looks at how it could affect climate change, finding that individual carbon dioxide emissions decline in old age as the elderly drive less and buy fewer carbon-intensive goods.
Via their consumption patterns, Americans produce a steadily increasing amount of CO2 emissions from age 10 until age 65, when they hit their peak of about 14.9 metric tons per capita annually. After that, the amount falls to 13.1 metric tons by age 80, according to the study by demographer Emilio Zagheni of the Max Planck Institute for Demographic Research in Rostock, Germany. No data are available for higher ages, but he expects emissions to fall further.
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Zagheni figured how many dollars an average U.S. resident spends at different ages on nine energy-intensive -- and thus CO2-intensive -- products and services, including electricity, gasoline, and air travel. He found middle-age adults fly and drive cars more frequently than young people, and they use more electricity. The elderly devote more dollars to health care services, which generally produce low levels of greenhouse gas emissions, and fewer to clothing and gasoline.
So what kind of impact will this have on climate change?
The study says the impact on climate projections will be significant, citing U.S. Census Bureau projections of an increase in life expectancy in the U.S. from today's 78.3 years to 83.1 years by 2050. Worldwide, the United Nations projects the share of people age 65 and older will increase from about 8% currently to 13% by 2030.
Yet the study does not expect positive climate benefits for the U.S. in the near term. This is partly because Baby Boomers are the age group with the highest per capita emissions and large numbers of them won't reach age 80 until after 2030.
Much depends on the energy mix used by Americans and technological advances, which Zagheni's study does not account for. For example, the impact could be quite positive if electricity could be generated and distributed with fewer emissions, because the elderly use a disproportionate amount of it since they stay home more than younger people.
The economic models of other researchers show CO2 reductions through changes in the age structure can only be seen after 2050, when reductions of up to 20% could occur.
Wendy Koch has been a reporter and editor at USA TODAY since 1998, covering politics and social issues. She's begun a quest to build the most eco-friendly home her budget allows. She'll share her experience and give you tips for greening your home. More about Wendy