The graph above places our 21st century global economy in its long-term context. It plots Gross World Product (GWP), the global aggregation of Gross Domestic Product (GDP). The time frame is the past 2,015 years: 1 CE (or AD) to 2015 CE. The units are trillions of US/international dollars adjusted for inflation (converted to 1990 dollars). The main source is Angus Maddison. Pre-20th century values are, by necessity, informed estimates by Maddison.
The year 1870 is marked with a white circle. In the millennia before 1870, the size of the global economy barely grew at all. Then, not long before the eve of the 20th century, all Hell broke loose. The most recent ten or fifteen decades appear in our historical economic record like an explosion. For perhaps 98 percent of human history, the economic trendline has been almost flat—horizontal. Over the past century-and-a-half it has been almost vertical.
The late-19th, 20th, and early 21st centuries have not been “normal.” They have been extraordinary and wondrous. Equally extraordinary is how far we have gone to normalize what is clearly an abnormal situation. Though our lifestyles and expectations are now tightly bound to near-vertical trendlines we talk and act as if nothing out of the ordinary is happening, and that we can count on more of the same for the foreseeable future.
Moreover, the 20th and 21st century exceptionalism on display in this graph is not limited to economic growth. Graphs of energy use, population, cotton or iron production, water withdrawals, food production, automobile numbers, air-travel miles, and nearly any other economic metric will look nearly identical to the graph above: millennia of little or no growth, then a sudden spike. There is upon the Earth a wholly new kind of civilization.
Graph sources: Angus Maddison, The World Economy, vol. 2, Historical Statistics (Paris: OECD, 2006) Tables 7b and 8b; and World Bank, “World DataBank: World Development Indicators: GDP at market prices”