Europe stumbles, China slows, and the U.S. struggles to regain its economic footing. But despite all the talk of deleveraging, there's just one thing we should keep in mind before we get too pessimistic about prospects for the global economy:
The world is growing like crazy.
Just check out this chart from the Economist (via economist Xavier Sala-i-Martin), which delineates the percentage of economic output amassed in the last two thousand years by century, adjusted for inflation. Probably unsurprisingly, humans produced 55% of modern history's GDP in all 100 years of the 20th century.
More astonishing is that we've already produced 23% of economic output in the common era in the 21st century—and we're only on our twelfth year!
Bottom line: boom and bust cycles may come and go, but the global economy is still growing exponentially.

economic output ever
The Economist via Xavier Sala-i-Martin