Books interview with Andrea Wulf: "Alexander von Humboldt is the forgotten father of environmentalism"

Why did you write this biography?

I’m from Germany, where Alexander von Humboldt is a big name – but very few people have heard of him in the UK or US. So I knew about him from when

I was younger, but then forgot about him. Later, whenever I started a book, he kept popping up because he was such a polymath – he had his fingers in every pie.

He was the last of the polymaths, in my opinion. When he died in 1859 it was the last moment at which one person held all the knowledge in their head that he did. After that point, scientists begin to fall into specialised fields of narrow expertise.

He also had an extraordinary memory: he could remember the shape of a leaf, or the colour of soil, across decades and decades and distances of thousands of miles. That’s why he was able to look at nature as a global force, because he could remind himself while he was in the Alps that he’d seen something in the Andes, for instance.

Can we trace how Humboldt saw the world back to when he was young?

To some extent. He was a typical child of the Enlightenment, I’d say, brought up in a very privileged and wealthy aristocratic Prussian family. His father died when he was young, and his mother was very cold, emotionally, but what she did do was provide a string of amazing Enlightenment teachers.

Where he was brought up was important too. Tegel, the family estate, is set among huge forests near Berlin. Unlike his brother – who was very happy with books – Alexander was always running around, coming back with his pockets stuffed full of shells, seeds, plants and insects.

So he was brought up within nature, with Enlightenment ideas. And then he met Johann Wolfgang Goethe, who at that time was Germany’s greatest poet. Humboldt later said that it was almost as if Goethe gave him new organs with which to view the world. One of the extraordinary things about Humboldt is that he straddled the Enlightenment and Romanticism: he said that we can only understand nature if we look at it with reason and with our feelings, our emotions and our imagination.

How important was his ability to understand new technology?

I think it was incredibly important. We tend to see historical figures in a romantic way and yes, Humboldt really understood nature, but he was also fascinated by all kinds of new technology. One of the reasons it took him so long to prepare for his expedition to South America is that he wanted to buy the best instruments he could. He travelled around Europe to find apparatus, and then took it to the experts to learn how to use it. In the end he took 42 devices, schlepping them over the Andes and down the Orinoco.

Did he enjoy the experience of travelling to South America?

Prussia was almost this intellectual corset imposed on him, so I think he felt absolutely liberated going to Latin America. He always said that scientists had to leave their labs and be outside in nature to understand it.

Most historians don’t want to touch this subject, but he was probably gay, so this was also a moment when he could just be who he was without anyone checking up on him.

I think he expressed a lot of his frustration in his personal life through physical exertion. As he put it: “I don’t have sensual needs.” Instead, he climbed mountains. What he did physically is absolutely mind-blowing. His team crossed the Andes again and again – 2,500 miles of one of the harshest landscapes you could possibly imagine. By the time they climbed Chimborazo, a volcanic mountain in the Andes, Humboldt was the most experienced mountaineer in the world. This was not a scientist who sat in an ivory tower.

Of all the things that he saw in South America, which was most important?

I think it was the Chimborazo. This was the moment when three years of travelling came together for him. He climbed 20,000 feet, almost to the top, of this mountain that was believed to be the highest in the world. No other person had been higher than he was.

Humboldt looked down and saw mountain ranges folded below him, and realised that the journey he’d taken from Quito in Ecuador, about 100 miles away, had taken him through tropical vegetation; through alpine plants, moss and lichen, to the line of eternal snow. And he understood that, rather than seeing the plant world in terms of classification, we should see it in terms of vegetation zones. This was the moment that he understood that nature is a global force.

The fascinating thing about Humboldt is that he’s not primarily important for the discovery of one thing: instead, he comes up with a new view of the world. Throughout his life he talked a lot about the glimpses you have from above, the glimpses that show you that everything comes together.

How did Humboldt develop his idea that everything is connected?

I think it was because he travelled so much. As a young man he went all over Europe as a mining inspector, and then later he visited the US and Siberia. At that time not many people had seen so much, and they definitely weren’t scientists who could remember everything they had ever seen!

It became very clear to Humboldt that there were connections across the globe, and he became obsessed with taking temperatures. Until then, this data had been recorded in long tables, but he came up with the extraordinary approach of drawing maps of the world featuring isotherms – the lines that we see on weather reports today, linking parts of the world experiencing the same temperature. When you look at the data like that, everything becomes so much clearer.

I really think that we can see Humboldt as the originator of comparative climatology.

But if everything hangs together it can all go wrong, because if you pull one thread the whole thing might unravel. When Humboldt was in South America he saw the devastating environmental effects of monoculture, irrigation and deforestation, and was the first to predict harmful human climate change. It’s amazing, because in 1832 he predicted the three ways that humankind can destroy the environment: through irrigation, the felling of forests, and industrial emissions.

His work led to a lot of fame, didn’t it?

Yes, and as much as I adore Humboldt, he was quite flawed. The more famous he became, the harder he found it to understand that he wasn’t the centre of attention.

There’s an amazing moment in 1842 when Charles Darwin finally met Humboldt, who was a huge hero for him, and the reason that Darwin went on his scientific voyage on the Beagle. And Darwin was utterly disappointed, because he couldn’t get a word in.

Despite this fame, Humboldt is now not that well known. Why is this?

The first reason is that he was a polymath, so when he died – the point at which scientists began to specialise – these ‘experts’ looked down at him for knowing everything. They saw it as making him an amateur, almost.

The other reason is that he was German. He was famous until the First World War, which was really not a great time in the UK or the US to celebrate a German scientist. The United States, particularly, had been in love with Humboldt, but during this period they burned German books and renamed streets originally titled in his honour.

What are Humboldt’s key legacies?

He gave us an idea of nature, as a web of life, that continues to shape how we see it. His interdisciplinary, holistic view is also hugely important. We now have such a sharp line between the sciences and arts, and I think we could do with adopting his approach of bringing together the subjective and objective, of combining scientific curiosity with an emotional response to nature.

As a historian I think it’s really important that we know where our roots are and what our history is, and it seems to me that the environmental movement is really lacking a historical, philosophical base on which they can build. Humboldt’s ideas are now so seemingly obvious that we’ve forgotten the man behind them. I’d say a lot of nature writers are still following in his footsteps –even though they may never have heard of him. If you think of something like Rachel Carson’s 1962 book Silent Spring, she could only have come up with the argument that nature is an interconnected whole because of Humboldt. He is the forgotten father of environmentalism and of nature writing.

Most important, though, is the fact that he predicted human-induced climate change. I think it’s time to remind ourselves that this has been an issue for a very long time, and is something that I believe we really need to tackle – and, I’d argue, through a Humboldtian approach. He believed in the exchange of knowledge between the sciences, and that is incredibly important today.

If you could somehow travel back in time and ask Humboldt a question, what would it be?

I would ask him how we’re going to deal with climate change. He was always so up-to-date, so he would know what to do.

The Invention of Nature: The Adventures of Alexander von Humboldt, the Lost Hero of Science by Andrea Wulf (John Murray, 496 pages, £25)