There's no getting back to nature: humanity has been changing Earth's landscape for millennia

Neanderthal man thinks about what he's done. (Okay, he was probably extinct already.) Image: AFP/Getty.

What is natural? It is often assumed that natural is better than artificial. Getting back to nature is something we should aspire to, with kids in particular not spending enough time in nature.

But if you want to escape civilisation and head into the unaltered wilderness you may be in for a shock: it doesn’t exist.

New research now suggests that there are practically no areas that have escaped human impacts. But not only that, such impacts happened many thousands of years earlier than is usually appreciated. In fact, you’d have to travel back more than 10,000 years to find the last point when most of the Earth’s landscapes were unaffected by humans.


The study, published in the Proceedings of the National Academies of Sciences and led by Nicole Boivin of the University of Oxford, catalogued changes in the abundance and diversity of plants and animals at the same time as human societies and technologies spread across the globe.

There is good fossil evidence for modern humans – Homo sapiens – being present in East Africa as far back as 195,000 years ago. Some 180,000 years later, humans were found on every continent except Antarctica. Over this period there were a series of collapses in biodiversity, with particular instances of extinctions of megafauna, non-domesticated land animals weighing more than 44kg.

Between 50,000 to 10,000 years ago, at least 101 of the 150 groups of megafauna species became extinct. There is much debate as to whether the disappearance of megafauna such as mammoths or mastodons was a direct result of human hunting, or a response to other factors. Correlation does not necessarily lead to causation: so evidence that large number of species disappeared from some regions around the same time as humans appearing could be due to a common factor such as changes in climate as the glaciers of the last ice age retreated.

Boivin’s study doesn’t produce a smoking gun that proves humans were responsible for such extinctions. Rather it uses traditional and new archaeological techniques to produce flint axes, plant pollen and burnt forest remains as evidence of the impacts humans had.

Extinction grabs our attention, but the data the international team has assembled tells a story of rapid change in not just the total number of species around the time that humans appear, but also the numbers of individual plants and animals in these ecosystems. Hunting and land clearing are the two main culprits in the oldest period they study – the Late Paleolithic (ending 10,000 years ago).

The study maps the spread of crops like wheat (A, in red) and livestock (Cattle, in blue) against the spread of human civilisation. ImagE: Boivin et al/PNAS.

After that, impacts shift up a gear with the development and rapid spread of agriculture. By this time roving bands of hunter gatherers begin to settle and plant crops and herd cattle. Today, we are used to looking out of an aircraft window to see broad expanses of intensively farmed monoculture crops. This trend began with the very first farmers who replaced diverse habitats with a small number of cultivated plants that in time would spread across the Earth, replacing whatever ecosystems they encountered.

The development of agriculture also included the domestication of animals, a few of which have expanded their ranges along with humans. Domestication of chickens happened some 10,000 years ago in East Asia. Earth is now home to over 20bn chickens, making it the most abundant bird species by some margin. The vast majority of the mass of land animals is now made up of humans and their domesticated species of cattle, pigs, sheep, goats and chickens.

When you include the accidental introduction of animals such as rats and invasive plant species, human agriculture meant profound alteration or sometimes complete replacement of indigenous ecosystems. The starkest examples of such changes are to be found on islands which often have high numbers of species that are not found anywhere else. Some examples are documented in more recent human history – the 17th-century extinction of the flightless dodo from the island of Mauritius being the most famous.


As well as detailing some of the havoc that humans have wrought on the biosphere, the researchers also highlight some positive interactions humans had. For example, the long presence of prehistoric societies that flourished within the Amazon basin show that careful stewardship of ecological resources – in that instance the cultivation of rich productive soils – can enhance ecosystems and provide sustainable livelihoods.

This is perhaps the most important lesson gained from the study. If we are to feed and care for the 9bn people that will be living on Earth by the middle of this century, then we need a more subtle and complex understanding of nature and sustainability.

The industrial age we now live in has taken human impacts to a planetary scale. We are changing the global climate and some argue that we have become a geological force. We can neither get back to nature nor continue as we are.

The state of nature – the situation of humans before the formation of societies – is a well used thought experiment in philosophy. It asks us to consider how societies and governments arise. What makes a good society? What is the moral basis of taxation?

An ecological state of nature – the biosphere as it was before human interference – is sometimes used in a very limited way when managing contemporary ecosystems. The assumption can be that we should simply strive to revert them back to their natural state. But can we say what that state is?

Alternatively, it could be used to pose both philosophical and practical questions. What sort of Earth system do humans want to live on? What is the role of other species in human well-being? What is the moral status of non-human animals?

Research that probes our ancient interactions with the rest of life on Earth can help us address such questions and so understand our current predicament. It remains to be seen whether Homo sapiens – which let’s remember is Latin for wise person – have the intelligence to learn from past mistakes and forge a sustainable future on Earth.The Conversation

James Dyke is lecturer in sustainability science at the University of Southampton.

This article was originally published on The Conversation. Read the original article.

 
 
 
 

How can cities become more bike friendly? The Netherlands offers useful lessons

(Aurore Belot/AFP via Getty Images)

It might seem like cycling is in the DNA of the Netherlands, a country where even the prime minister takes his bicycle to work. But the Dutch haven’t always lived as one with their bikes. In the Amsterdam of the early 1970s, cars were considered the wave of the future. They can be seen filling up squares and streets in historical photographs, and killed an average of over two Amsterdammers per week, including many children.

It is nothing more than an “accident of history” that the Netherlands embraced cycling, says Marco te Brömmelstoet, the director of the Urban Cycling Institute in Amsterdam and a man better known as the city’s cycling professor. Today’s bike rider’s paradise was created after parents and activists took to the streets to protest “child murder” by car. A Saudi oil embargo, rising gas prices, concerns about pollution and anger about the destruction of entire neighbourhoods to build motorways did the rest. 


Amsterdam, 1958. Not a cyclist's paradise. (Keystone/Getty Images)

What’s important about this history is that it can be replicated in other cities, too. Of course, the Netherlands has certain advantages – it’s flat as a pancake, for example. But in the eyes of traffic reformers, the rise of e-bikes (and even cargo bikes) means there’s no excuse for prioritising cars everywhere. 

So how can cities, flat or not, follow Amsterdam’s path to creating places where cycling is a pleasant, safe and common way to get around? The Dutch have some tips. 

Separate bikes from car traffic

Any city could start painting dedicated bike lanes on the streets. But in the Netherlands, those white marks indicating space for cyclists are considered just a minor first step. 

“A line on the road is not enough. Motorists will ignore it,” says Frans Jan van Rossem, a civil servant specialising in cycling policy in Utrecht. If other cities want their residents to choose bikes instead of cars when dodging pandemic-era public transport, protecting them from fast-moving car traffic must be the priority, Van Rossem says. 

The Dutch research institute CROW developed a widely praised design manual for bicycle infrastructure, full of tips for creating these protected lanes: A row of vertical white posts or a curb can serve as a physical separator, for example. Still, cyclists tend to feel safest in a "solitary" path, separated from the road by grass, trees, or an elevated concrete island. 

“The main bottleneck, the main reason why people don’t cycle, is that they don’t feel safe,” Van Rossem notes. “To start, construct separate paths.”

Turn those bike paths into a network

Many cities may have some bike lanes on some streets, but leave cyclists to roll the dice everywhere else. Will conditions still be safe when they turn left or right? Often they have to continue their way without any protected facilities for cyclists. 

“In many cases, cities take fast action, without thinking it through very well,” says Lucas Harms. He leads the Dutch Cycling Embassy, a partnership between the Dutch government and several companies, which promotes Dutch bike knowhow globally. “Don’t build small pieces of bike lane from nothing to nowhere. Think about a network of cycling infrastructure.” 

Utrecht aims to have cyclists within 200 to 300 metres of a connected path anywhere in the city, Van Rossem says. Avoid constructing those paths in sketchy industrial areas, he warns. “A connection through an unattractive area may be fast, but won’t be used a lot.”

Embrace the ‘fietsstraat’, a street where bikes come first


On some streets, drivers have to give up their privileges. (Rick Nederstigt/AFP via Getty Images)

A peculiar Dutch invention called "fietsstraat" (cycling street) holds strong potential for the rest of the world, Kevin Krizek says. He’s a transportation professor from Colorado who spent three years at Radboud University in Nijmegen. 

On cycling streets, cars are “guests”, restricted by a speed limit of 30 kilometres per hour. Drivers are not allowed to pass, so cyclists comfortably dominate the road. In the Netherlands the fietsstraat is usually paved with red asphalt, to resemble a bike path and notify drivers of their secondary status. But creating a cycling street can be easy. “All you need to do is put signs at intersections,” Krizek says. The effect is revolutionary in his view. Drivers have to give up their privileges, and cyclists can take the lead. 

Some Dutch traffic experts worry the cycling street won’t work if a city doesn’t also have a robust cycling culture. In the Netherlands, drivers are aware of the perils of urban cycling because they too use bicycles. Moreover, Dutch cities use sophisticated “circulation plans” to direct cars away from city centres and residential areas, onto a few main routes. 

Without “calming” traffic this way, the cycling street could be a step too far, Harms says. “In a city like New York, where all roads are equally accessible and full, it’s better to separate bicycles and cars,” he says.

Redesign intersections for cyclists' safety

If cyclists have to cross intersections “at the mercy of the Gods”, you’re not there yet, says Harms. When he travels abroad, he often finds clumsily designed crossings. As soon as cars turn, cyclists may fear for their lives. 

Harms recommends placing physical barriers between cars and bikes in places where they must cross. The Dutch build elevated islands to direct traffic into separate sections. The golden rule: cars wait behind bicycles. That way, drivers can see cyclists clearly at all times. Barriers also force Dutch cyclists to turn left in the safest way possible. They cross the street first and wait for their turn again before making their way left.

“You can create that with simple temporary measures,” Harms says. Planters work fine, for example. “They must be forgiving, though. When someone makes a mistake, you don’t want them to get seriously injured by a flower box’s sharp edge.”

Professor Krizek points out how the Dutch integrated cycling routes into roundabouts. Some are small; some are big and glorious, like the Hovenring between Eindhoven and Veldhoven, where cyclists take a futuristic-looking roundabout lifted above the highway. Most of those traffic circles move high volumes of cars and cyclists through intersections efficiently and safely. For a simpler solution, the Dutch manual suggests guiding cyclists to quieter streets – crossing a block up or down may be safer. “Nobody knows how to do intersections better than the Dutch,” says Krizek. 

Ban cars, or at least discourage them


A man rides down from a three-level bicycle parking garage near Amsterdam's main train station. (Timothy Clary/AFP via Getty Images)

The quickest, most affordable way to make a city more bikeable is to ban cars, says Ria Hilhorst, cycling policy advisor for the City of Amsterdam. It will make streets remarkably safe – and will most likely enrage a significant amount of people. 

Amsterdam doesn’t outlaw cars, but it does deliberately make their owners feel unwelcome in the historic city’s cramped streets. Paid parking is hugely effective, for example. Many car owners decide to avoid paying and use bicycles or public transportation for trips into the city. Utrecht, meanwhile, boasts the world’s largest bicycle parking garage, which provides a dizzying 12,500 parking spots.

To further discourage drivers from entering the city’s heart, Amsterdam will soon remove more than 10,000 car-parking spaces. Strategically placed barriers already make it impossible to cross Amsterdam efficiently by car. “In Amsterdam, it is faster to cross the city on a bike than by car,” Harms says. “That is the result of very conscious policy decisions.”

Communicate the benefits clearly

Shopkeepers always fear they will lose clients when their businesses won’t be directly accessible by car, but that’s a myth, says Harms. “A lot of research concludes that better access for pedestrians and cyclists, making a street more attractive, is an economic boost.”

Try replacing one parking space with a small park, he recommends, and residents will see how it improves their community. Home values will eventually rise in calmer, bike-friendlier neighbourhoods without through traffic, Van Rossem says. Fewer cars mean more room for green spaces, for example.

“I often miss the notion that cycling and walking can contribute a lot to the city. One of the greatest threats to public health is lack of exercise. A more walkable and bikeable city can be part of the solution,” says Ria Hilhorst. “But in many countries, cycling is seen as something for losers. I made it, so I have a car and I’m going to use it, is the idea. 

“Changing this requires political courage. Keep your back straight, and present a vision. What do you gain? Tranquility, fewer emissions, health benefits, traffic safety, less space occupied by vehicles.” 

Again, she points to Amsterdam’s history. “It is possible; we were a car city too.”

Karlijn van Houwelingen is a journalist based in New York City.