Dica do Thiago: How to cut carbon emissions
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How to cut carbon emissions
Don’t be middle-aged
Jan 21st 2012 | from the print edition
CARBON emissions vary hugely between countries. That is well known, as is the finding that rich people emit more than poor ones. But a newly revised paper* by Emilio Zagheni of the Max Planck Institute in Rostock, Germany also shows how carbon footprints vary by age—and the worrying implications of this.
Average spending patterns vary over a lifetime. Consumption as a fraction of household spending typically peaks when people are in their 20s. Old people drive cars less than do their children and grandchildren. Clothes spending peaks in (most) people’s 40s and declines thereafter. These choices have environmental results, because some kinds of economic activity are more heavily polluting than others.
Mr Zagheni took nine types of consumption—including electricity use, driving cars, buying clothes and food—and looked at how much Americans of each age group spend on them. He then calculated the CO2 emissions implicit in the consumption (the “carbon footprint”) to give a profile of carbon emissions by age. He found that Americans’ emissions per head rise sharply until they reach their early 20s. The increase continues more slowly until people are in their mid 60s, then tails off (see chart). The difference in the amount of carbon each cohort produces is large. In their early 20s, Americans produce less than ten tonnes of CO2 a year. At the peak, in their early 60s, they produce almost 15 tonnes. (America’s own most recent estimates from the Carbon Dioxide Information Analysis Centre in Tennessee put average emissions rather higher, at nearly 18 tonnes per person in 2008.)
Carbon emissions ebb as people enter old age. Because most rich countries are ageing, demography should therefore reduce atmospheric pollution. And it will—eventually. But the reduction does not begin until people are in their mid-60s and for the next decade or so, the number of people in the most polluting age group (60 to 64) will rise even more than the number of less-polluting geriatrics. In America in 2020 there will be 2.4m more people aged 75-79 than at present; but there will be 4.4m more 60- to 64-year-olds.
The growth of heavily polluting age groups will be still more marked in younger countries which are beginning to reap the economic benefits that come from an increase in the relative size of the working-age population. Members of this cohort will produce more pollution until they retire, meaning that the climate-change benefits of ageing populations will not kick in until 2050 at the earliest.