Led by Asia, the share of the global economy held by emerging markets has risen steadily over recent decades. For the countries of Asia — especially China and India — sustainable growth is no longer part of a global challenge. Instead, it has become a national growth-strategy issue.
Over the next few decades, almost all of the world's growth in energy consumption, urbanization, automobile usage, airline travel, and carbon emissions will come from emerging economies. By mid-century, the number of people living in what will be (by then) high-income economies will rise to 4.5 billion, from 1 billion today. Global GDP, which currently stands at about $60 trillion, will at least triple in the next 30 years.
If emerging economies try to reach advanced-country income levels by following roughly the same pattern as their predecessors, the impact on natural resources and the environment will be enormous and probably disastrous.