ECONOMIES CAN'T JUST KEEP ON GROWING
Humanity has made great strides over the past 2,000 years, and we often assume that our path, notwithstanding a few bumps along the way, goes ever upward. But we are wrong: Within this century, environmental and resource constraints will likely bring global economic growth to a halt.
Limits on available resources already restrict economic activity in many sectors, though their impact usually goes unacknowledged. Take rare-earth elements -- minerals and oxides essential to the manufacture of many technologies. When China recently stopped exporting them, sudden shortages threatened to crimp a wide range of industries. Most commentators believed that the supply crunch would ease once new (or mothballed) rare-earth mines are opened. But such optimism overlooks a fundamental physical reality. As the best bodies of ore are exhausted, miners move on to less concentrated deposits in more difficult natural circumstances. These mines cause more pollution and require more energy. In other words, opening new rare-earth mines outside China will result in staggering environmental impact.
Or consider petroleum, which provides about 40 percent of the world's commercial energy and more than 95 percent of its transportation energy. Oil companies generally have to work harder to get each new barrel of oil. The amount of energy they receive for each unit of energy they invest in drilling has dropped from 100 to 1 in Texas in the 1930s to about 15 to 1 in the continental United States today. The oil sands in Alberta, Canada, yield a return of only 4 to 1.
Coal and natural gas still have high energy yields. So, as oil becomes harder to get in coming decades, these energy sources will become increasingly vital to the global economy. But they're fossil fuels, and burning them generates climate-changing carbon dioxide. If the World Bank's projected rates for global economic growth hold steady, global output will have risen almost tenfold by 2100, to more than $600 trillion in today's dollars. So even if countries make dramatic reductions in carbon emissions per dollar of GDP, global carbon dioxide emissions will triple from today's level to more than 90 billion metric tons a year. Scientists tell us that tripling carbon emissions would cause such extreme heat waves, droughts, and storms that farmers would likely find they couldn't produce the food needed for the world's projected population of 9 billion people. Indeed, the economic damage caused by such climate change would probably, by itself, halt growth.
Humankind is in a box. For the 2.7 billion people now living on less than $2 a day, economic growth is essential to satisfying the most basic requirements of human dignity. And in much wealthier societies, people need growth to pay off their debts, support liberty, and maintain civil peace. To produce and sustain this growth, they must expend vast amounts of energy. Yet our best energy source -- fossil fuel -- is the main thing contributing to climate change, and climate change, if unchecked, will halt growth.
We can't live with growth, and we can't live without it. This contradiction is humankind's biggest challenge this century, but as long as conventional wisdom holds that growth can continue forever, it's a challenge we can't possibly address.
Thomas Homer-Dixon is the CIGI chair of global systems at the Balsillie School of International Affairs in Waterloo, Canada.
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