Dead trees stand in a recently deforested section of the Amazon rainforest near Abuna, Rondonia state, Brazil. (Mario Tama/Getty Images)

David Von Drehle’s Jan. 9 op-ed, “Don’t fall for the doomsday predictions,” suggested that the Earth can support 7 billion humans, but he misinterpreted the history of humanity’s impact on Earth. Thomas Malthus, though wrong about the timing and the precise mechanism, got the big picture correct in his 1798 “An Essay on the Principle of Population”: A relentlessly growing human population will consume more resources than Earth can supply.

With the Industrial Revolution, as Mr. Von Dehle stated, the “human race set off on a long tear of unprecedented economic growth and prosperity.” Our ingenuity created more efficient ways of extracting and using the natural resources of Earth. We were so efficient that 90 percent of the forest originally covering the lower 48 was cut down for shelter, fuel and agricultural land. Today, the primary cause of deforestation is agriculture. We have been clear-cutting the planet to feed ourselves for the 221 years since Malthus penned his prescient essay. The impact: rising carbon dioxide levels, climate change, soil erosion and declining water quality. The ecology of Earth moves on a time scale such that the effects of actions reveal themselves decades or centuries later. Some think the market will save us from environmental catastrophe as rising prices help “creative people figure out how to find more . . . or use less.” While ingenuity can result in more efficient energy use, global carbon dioxide emissions continue to rise, and only 30 percent of the Earth’s land is covered by forest. We can’t wait for the market to solve this problem or it will be well past too late.

George M. Hoke, Charlottesville