The Legacy of the Man Who Changed Our View of Nature

The 19th-century German scientist Alexander von Humboldt popularized the concept that the natural world is interconnected. In a Yale e360 interview, biographer Andrea Wulf explains how Humboldt’s vision helped create modern environmentalism.

He was a fearless world traveler, a polymath whose expertise included botany, geography, geology, and more. He viewed nature as a web of life, and, in a conclusion stunning in its prescience, he named deforestation and “the great masses of steam and gas produced by industry” as the causes of climate change. 

The name of the 19th-century Prussian naturalist Alexander von Humboldt has remained largely unknown in the English-speaking world in the modern era. But historian Andrea Wulf, in her best-selling book The Invention of Nature, aims to return Humboldt to his rightful place as, in her words, “the father of environmentalism.” 

Andrea Wulf

Andrea Wulf

In an interview with Yale Environment 360, Wulf explains what enabled Humboldt to arrive at conclusions that were astonishing for his time. “Most scientists who looked at climate then, looked at weather… But Humboldt very much sees climate as an interconnection of landmass, of altitude, of weather, of oceans. He puts all of this together.” Humboldt, she says, originated an entirely new genre of writing that made science accessible to the masses, combining empirical observations with soaring language. “He is completely unafraid of saying, ‘We have to use our imagination and our feelings to understand nature.’ No other scientist was doing that at that time.” 

Today’s environmentalists, Wulf says, can find inspiration in Humboldt’s work. “When I look at today’s environmental debate in the political arena, I’m really missing this sense of awe for nature, this recognition that we are only going to protect what we love.” 

Yale Environment 360: We learn in your book that Humboldt’s purpose in his epic journey to Latin America was to discover how, in his words, “All forces of nature are interlaced and interwoven.” How radical was that way of thinking, in 1799? 

Andrea Wulf: Very radical. Basically, Humboldt comes up with this idea that nature is a web of life, that it’s almost like a tapestry. He describes Earth as a living organism, and that’s something completely new, in the sense that, until then, nature was really much more seen as a more mechanical system. 

At that time, scientists were looking into the difference between organic and inorganic matter, but he’s really the one who is talking different disciplines, and he puts them together and creates this new concept or vision of nature that is very different. You do have scientists in Europe then thinking about the vital force in organisms. But Humboldt is taking this concept and he is applying it to the whole of nature, and that was really what was so new, because he sees global connections. For example, he is the first to define global vegetation and climate zones. 

e360: He also perceives the effect of deforestation on climate. He would eventually point to other causes of environmental degradation, including monoculture, and in his words, “the great masses of steam and gas produced by industry.” He writes, “Everything is interaction and reciprocal.” Was it the fact that he was a polymath that allowed for these stunning insights? 

Wulf: I think there are several things. Because he is a polymath and he does not stick to one discipline, he can look across these boundaries. For example, most scientists who looked at climate then looked at weather. You have, for example, Thomas Jefferson, who was obsessed with it, who measured the temperature every day, and the wind, and the humidity. But Humboldt very much sees climate as an interconnection of landmass, of altitude, of weather, of oceans. He puts all of this together. And he can do that because he is interested in the weather, but he is also interested in plants and in soil. He brings all of these disciplines together. 

Quite a lot of his contemporaries remarked upon his incredible memory. He could remember the shape of a leaf 40 years later. He could remember exact layers, rocks strata decades later. When he was standing, for example, in the Altai Mountains in Russia, his mind would race back to what he had seen in the Andes. Or when he was standing in the Andes, his mind would race back to what he had seen in the Alps. So he can make these connections. And then I think there’s one thing we tend to forget: At that time, not a lot of scientists actually saw as much of the world as Humboldt did. They were basically stuck to the place where they were brought up, and maybe they moved around a little bit, but there were very few trained scientists who were traveling the world.

Alexander von Humboldt and French botanist Aimé Bonpland in the Amazon rainforest.

Alexander von Humboldt and French botanist Aimé Bonpland in the Amazon rainforest. Oil painting by Eduard Ender, 1856

e360: Humboldt’s book, Views of Nature, was a roaring bestseller. It combined science and beautiful prose. You call it a blueprint for nature writing today. Why was it so revolutionary? 

Wulf: He is completely unafraid of lyricism. He is completely unafraid of saying, “We have to use our imagination and our feelings to understand nature.” No other scientist was doing that at that time. Scientists were writing these very specialized books for their colleagues basically. But Humboldt, because he believed that knowledge should be accessible for everybody, he was democratizing knowledge. That is one of his greatest achievements. He writes these books for a general audience, not for specialists. 

Views of Nature is a beautiful example of that. In each chapter, he describes nature in very poetic ways. He is talking about “leaves that unfurl and greet the morning sun.” That’s not how a scientist would have written about nature. But then, at the same time, at the end of each chapter, he has these very long endnotes, which include the latest scientific results and discoveries. So if you were a layperson you could just skip over those. But if you were a scientist and you are really interested in the detail, you would also read them. 

e360: You talk about his democratization of science. He also went on lecture tours and spoke to packed crowds that included women. 

Wulf: Humboldt basically took his audiences on these incredible journeys from Earth to outer space, from the tiniest insect to the tallest trees. He talks about human migration, he talks about the Northern Lights. He never read from his notes — he just kind of talked, so he was very, very lively. And he did not charge anything for these lectures, and that was something no one else was really doing. The audience consisted of students, and artists, and carpenters, but also servants and kings. And many of them were women, so he made the knowledge available to everybody. 

He uses uncomplicated language, and he uses these kind of poetic, evocative landscape descriptions. He wanted to make people excited about science and nature, and he had this sense of wonder for nature. I think that’s why I say it’s a blueprint for nature writing today. John Muir, for example, was very much doing the same thing as Humboldt in the sense that he would take readers from the East Coast and literally grab and take them into Yosemite with his descriptions. And nature writers today do that – having scientific observations in there, but also the sheer joy of, say, walking through nature. 

e360: You mention John Muir, and you go into some detail regarding this American environmental lineage that originates with Humboldt. Speak a bit about that. 

Wulf: I think that was for me one of the greatest surprises when I was doing this book, because when I got interested in Humboldt and I was talking to people about it, the most common reaction I got, “Who is this?” Then I started the research, and I realized just how unbelievably famous he was or used to be in America and the huge impact he had on people like John Muir. Muir, for example, as a young man said, “How intensely I want to be a Humboldt.” He read Humboldt’s books with pencil in hand, and amazingly these books still exist at the University of the Pacific in Stockton, California, so we can look at Muir’s library, at his copies of Humboldt’s books. They are heavily underlined. It’s almost like listening to Muir having a conversation with Humboldt. And we can see through this how much he was influenced by Humboldt in his ecological thinking. 

For example, he underlines basically everything that Humboldt says about deforestation and the destructive effect of agriculture, but also this idea of nature as a web of life. There is this very famous Muir quote, which is basically, “If you pull at something in the universe, you’ll find it hitched to everything else.” That’s … pure Humboldt. This idea that everything is connected, and only if you understand that everything is connected can you really understand how we are threatening nature. That’s the bit that Muir takes from Humboldt. And the other thing that he takes from Humboldt is this sheer joy of nature. 

A botanical drawing by Humboldt of a plant in Cuba.

A botanical drawing by Humboldt of a plant in Cuba.

e360: You write that the connection between knowledge, art, and poetry, between science and emotions – Humboldt called it “the deeply-seated bond” – is more important than ever. How so? 

Wulf: When I wrote this book, at first what was most important for me, was to say he is the forgotten father of environmentalism, and I still think that is incredibly important. But the more I researched him, the more I thought the most important thing is that he does not draw a sharp distinction between the arts and the sciences. I think that’s something that we are really lacking at, and it’s a quite new, sharp line we are drawing. It starts really in the mid-19th century with the specializations of the sciences, but think that when I look at today’s environmental debate in the political arena, I’m really missing this sense of awe for nature, this recognition that we are only going to protect what we love. 

I think Humboldt is so amazing in that he is so utterly unafraid of embracing that [sense of wonder], while at the same time he is utterly obsessed with scientific measurement. He schlepped 42 scientific instruments across Latin America, so he was not a misty-eyed romantic. He believed, on the one hand, in the hard facts of science. But he also believed in wonder. 

I think that is something I feel in the whole climate change debate that’s really missing. Because we can throw numbers forever at people, you know, this is what’s going to happen if the temperatures rise 2 degrees. But it’s very often through examples, through being in nature, that we realize the threat to nature. I think we can’t just leave climate change to scientists alone; I think it’s something that has to work on many levels, not just on the scientific level, if we want to do something about our planet. 

e360: You anticipated my next question. I was going to ask you about the 800 or so scientists who recently signed an open letter to President-elect Trump, calling on him to take the threat of climate change seriously. I was wondering if Humboldt were around today, as those scientists continue to press the Trump administration, what would Humboldt’s words of wisdom be to them?

Wulf: I try to avoid to put words or thoughts into Humboldt’s head, because I really don’t know. I think he definitely would have been one of those scientists signing that letter, but I don’t know. I’m as flabbergasted about the Trump election as everybody else, I think. I’m terrified to have a climate change denier as the next president of the United States, if I’m honest.