Human-induced climate change was first identified in 1800 and again in 1831 by the same scientist, Alexander von Humboldt
Though little known and studied today, Alexander von Humboldt (b. September 14, 1769) was a legend in his lifetime, and remains one of the most important scientists in history. More places and species are named after Humboldt than after any other human being. […] As people around the world become more aware of how vulnerable living systems are to global warming, Humboldt’s insights and writings seem more than prescient. He is the first person to describe the phenomenon and cause of human-induced climate change, in 1800 and again in 1831, based on observations generated during his travels.
Humboldt was searching for the “connections which linked all phenomena and all forces of nature.” Russia was the final chapter in his understanding of nature—he consolidated, confirmed, and set into relation all the data he had collected over the past decades. Comparison not discovery was his guiding theme. Later, when he published the results of the Russian expedition in two books, Humboldt wrote about the destruction of forests and of humankind’s long-term changes to the environment. When he list the three ways in which the human species was affecting the climate, he named deforestation, ruthless irrigation, and, perhaps most prophetically, the “great masses of steam and gas” produced in the industrial centers. No one but Humboldt had looked at the relationship between humankind and nature like this before. – DRAWDOWN – THE MOST COMPREHENSIVE PLAN EVER PROPOSED TO REVERSE GLOBAL WARMING – EDITED BY PAUL HAWKEN (book excerpt)