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Older Americans do go a little easier on greenhouse gases than others, simply because they drive less about 60% as much as middle-agers. But transportation in all forms accounts for only 29% of greenhouse emissions. Another 17% comes from heating, cooling and powering homes, a contribution we all make.
Garbage is also a scourge that knows no age. The exact things you throw away may change over the course of your life more electronic trash like old computers or cell phones when you're younger, more grocery and pharmaceutical waste when you're older but that's not the relevant concern. "The question is not so much what the mix is," says Elgie Holstein, a land, water and wildlife expert for the Environmental Defense Fund (EDF). "It's what the total quantity is."
The nation's demand for food will expand too, but that's probably not a worry. The American agricultural sector is the most efficient in the world, producing 3,800 calories per American per day, even though a healthy diet requires no more than 2,500. "We are already a major exporter of food," says Holstein. "We would not have to dramatically increase our food production."
Water is a different matter. Americans consume an average of 160 gal. (600 L) of water per person per day at a moment when the overall supply of fresh water is dwindling because of a growing population and increasing droughts. The Colorado River, for example, is already being pushed beyond its capacity, required to serve 27 million people in seven southwestern states. By 2021 it will no longer be up to the job. Similar if not always equally dramatic challenges confront nearly every region of the country. "There are some parts of the U.S. that can handle only so many people," says EDF water specialist Spreck Rosekrans. "But there are still things we could do to stretch the water supply and support a larger population."
There are solutions at least theoretical ones to nearly all of the problems increased longevity would bring. For water, the answer is a mix of conservation and incentives to upgrade irrigation and industrial water systems, as well as better regulation of water markets so that wet regions can more readily sell their surplus to dry ones. The trash problem can be addressed by reducing packaging and boosting recycling; greenhouse gases can be slashed by switching to renewable energy and pricing carbon to make new technologies more attractive. Even the medical expenses associated with long life can be reduced by a combination of methods such as better preventive care and doing away with the fee-for-service model in favor of bundled payments for entire procedures. Medicare pilot programs for several such initiatives are already included in the health care legislation now before Congress.
And yet no matter what policymakers do to accommodate a bigger, older population, the hardest and most important work will still have to be done by the people who know the seniors best their families. According to the U.S. Census Bureau, from 2000 to '07 the number of aging parents who have moved in with their adult children so-called boomerang seniors jumped from 1.4 million to 2.1 million, or 50%. That's still less than 1% of the population, but the trend is unmistakable, and a punishing economy combined with greater longevity means it's not likely to change soon. The emotional and fiscal stress this places on heads of households who often haven't even finished rearing their own kids can be enormous.
More important for the superannuated seniors themselves is whether they'll have the wherewithal to enjoy their extra years, no matter where they're living them. The ancient Greeks told the cautionary tale of Eos, the goddess who fell in love with the mortal Tithonus. Eos asked Zeus to give her lover the same eternal life she enjoyed, but she forgot to ask for eternal health for him too. Tithonus eventually aged, sickened and withered but could never die. It's not for nothing that doctors urge us to eat well, get sufficient exercise and stay intellectually active as we age. None of those things guarantees us longevity, but they do help ensure that if we're lucky enough to get extra years, we'll be well enough not to waste them.