The Anthropocene marks relentless and increasingly grave environmental degradation as the Earth faces tipping points for climate change, biodiversity and survival. To address these ills, scientists say we can learn valuable lessons from the past.
“As our planet emerges into a new epoch in which humans dominate the Earth system, it is imperative that societies initiate a new phase of responsible environmental stewardship,” researchers write in the journal Nature Ecology & Evolution.
“Maintenance of the Earth’s current ecological trajectory threatens not only countless other species but also critical ecosystem services that support human societies.
“Here we argue that information from the past has a valuable role to play in enhancing the sustainability and resilience of our societies.”
As well as learning from past mistakes, Nicole Boivin and Alison Crowther, both affiliated with Germany’s Max Planck Institute and the University of Queensland, stress how historical success stories can be integrated with contemporary solutions.
In doing this, they say that archaeology, history and palaeoecology offer a vast resource that we should tap into to build on efforts to create a better future and a “good Anthropocene”.
“We have at our fingertips a huge amount of information about how humans in the past have tried to solve many of the same problems we face today,” says Crowther. “Many of these solutions have been tried and tested over millennia; we know which ones worked and which ones failed, and why.”
The review explores how historical data can be mined to improve biodiversity, conservation, fire management, carbon sequestration, soil sustainability, food security and agricultural sustainability, as well as mitigating pollution, building more sustainable cities and boosting resilience to climate change.
For conservation, archaeology and palaeoecology offer insights into ecological baselines to understand how change occurred naturally before humans plundered onto the scene.
“Work in restoration ecology requires understanding of the degree of change that has occurred from baseline conditions, the natural, climate-driven shape of ecosystems prior to human intervention,” write Boivin and Crowther.
In some instances, they note, past human activity added value to the planet, such as Canada’s Garry oak ecosystem, the formation of which has been attributed to indigenous peoples’ burning regime.
“Accordingly, conservationists are increasingly embracing novel ecosystems and recognising that ecosystems created via long-term human management are equally valid targets for conservation.”
Archaeology also tells us about past removal of species and successes or failures of efforts to reintroduce them, which can help us understand those species’ ranges and endemic status.
In Australia and elsewhere, Indigenous and prehistoric fire-management practices are increasingly recognised by forest and land managers as effective ways to create fire-resilient communities and ecosystems – a burning issue with looming threats of longer, hotter dry spells and more intense fires.
Agricultural practices also pose a major problem as “humans today control a vast and disproportionate share of the planet’s resources,” contributing to climate change, biodiversity and habitat loss and groundwater depletion.
Modern agriculture destroys forests and ecosystems and humans’ unbridled population growth threatens food security. For this we can again turn to indigenous cultures for insights.
Some of their practices include sustainable irrigation, terracing and systems such as raised-field agriculture. The latter, once used across South and Central America before the Spanish came along, has been attributed to better drainage, soil aeration, moisture retention and fertility.
Already, people have tried to rehabilitate prehistoric agricultural methods, for example in the Peruvian Andes where pre-Hispanic terraces have been reintroduced. Many lessons can be learned from these efforts, note Boivin and Crowther, such as the importance of engaging local communities and observing markets.
Other insights come from the eastern Amazon up to 4500 years ago, such as complex agroforest practices – rather than modern unsustainable monocrops – that grew multiple crops while creating edible forests.
Archaeology can also help explore ancient resilient crops such as millet, a heat-tolerant cereal that colonists replaced with thirsty, labour-intensive maize.
“By reviving local crops and other forms of local agriculture we can better address the food crises that we face globally with population growth and climate change,” says Crowther.
All of this relies on healthy soil, she and Boivin note. “Soil lies at the base of all human subsistence systems,” they write, “and soil retention and improvement were key foci of human activity in many regions of the world for thousands of years.”
Historically, humans created soils that were rich in organic matter, had better capacity to hold nutrients and moisture and were “remarkable” at sequestering carbon. Soil enrichment methods included adding algae to Maya gardens in Mesoamerica, and seaweed to topsoils surrounding the Baltic Sea, in Europe. African savannah soils were unintentionally enriched by prehistoric animal droppings.
We can also learn from past patterns of air pollution, a major health hazard that confronts us and reportedly impacted historical populations; how levels are estimated and how it accumulates and breaks down, for instance.
Ancient tropical cities in places such as Mesoamerica, Southeast Asia and the Amazon offer insights for sustainable cities. In Maya culture, for instance, households and domestic gardens were interspersed with agriculture in the city itself.
“These proximate food staple sources probably contributed to the longevity of many Maya cities,” write Boivin and Crowther.
Another example of urban agriculture they note is Byzantine Constantinople, which sustained people even during prolonged sieges.
“These early dispersed agrarian cities offer more sustainable, food-secure models of urbanism that are less dependent on fossil fuel and more resilient to food-supply shocks resulting from, for example, pandemics, conflict or climate change.”
Such cities also featured cultivation by smallholders, empowering local communities to control their activities and foster food security. Importantly, they included impressive water-conservation technologies.
Last but certainly not least, the researchers say we can learn from the past to build greater climate-change resilience, a topic that has long captivated archaeologists who seek to understand past human responses to climate changes. Peruvian archaeology, for instance, offers a window into El Niño patterns.
The authors urge that archaeology, in particular, be embraced by and take part in multi-disciplinary efforts to address modern challenges, as well as engaging with policy makers, Indigenous peoples and other stakeholders such as farmers, conservationists, rangers and local communities.
“We must work towards solutions that bring together the best of the past, present and future, integrating traditional and modern approaches to find the best way forward.”