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. His one hundredth birthday was celebrated all over the world with festivities and parades. More than 25,000 people gathered in Central Park to pay homage, 10,000 in Pittsburgh, 15,000 in Syracuse, 80,000 in Berlin, with thousands more in Buenos Aires, Mexico City, London, and Sydney. 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.

– Excerpt from: DRAWDOWN – THE MOST COMPREHENSIVE PLAN EVER PROPOSED TO REVERSE GLOBAL WARMING – EDITED BY PAUL HAWKEN (book)