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263. Humans and Forests: An Entangled Relationship

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MuseLetter #396 / March 2026 by Richard Heinberg Share Tweet Forward Read current MuseLetter online | Download printable PDF version here (PDF, 199 KB) The Future of Forests Our species’ origin and destiny are entangled with the roots and branches of trees. We evolved in and around trees, and we’ve learned to breed and plant them for their fruit, nuts, wood, and blossoms, taking their seeds with us as we migrated—hence the English walnut, native to Persia, and the Georgia peach, native to China. It’s a relationship that has carried us around the globe, often in boats or carts made from trees.

While human communities have benefitted immensely from trees, tree communities (i.e., forests) haven’t always fared so well in the bargain. In this article, we’ll trace the ups and downs of this relationship and inquire why it has grown more one-sidedly abusive in recent decades. Unsurprisingly, many recent challenges to the health of forests have emerged because of climate change—even as forests are proving to be one of the planet’s primary climate-stabilizing systems.

Finally, we’ll explore what we can do to defend and restore forests in the face of global warming and other threats. Along the way, we’ll dip into some of the most intriguing recent scientific findings about trees and forests. The Ghosts of Forests Past During recent millennia, the world’s forests have changed in size, composition, and sometimes location. Consider central Europe: During glacial times, the region was mostly treeless; but starting about 10,000 years ago, with higher temperatures and melting ice came the flourishing of dense oak, lime, and hazel forests, forming a mosaic pattern across the landscape. During this period, human settlements gradually expanded, adding farms, gardens, and pastures to the mosaic. As centuries passed, and as agriculture and metal smelting proliferated, more trees were cut for wood, for fuel, and to clear land for planting annual crops and for pasturing animals. Forests contracted and sometimes expanded according to human priorities. However, by the 16th century, holznot (German for “wood shortage”) had become a persistent problem—one that contributed to the widespread adoption of coal and, later, other fossil fuels. Today the ancient central European forest is nearly gone, and its remnants are under threat.

North America saw a similar evolution. In 1800, the region of what is now the southeastern United States was covered by a vast, 93-million-acre expanse of old-growth longleaf pine stretching from Virginia to
Texas. This arboreal ecosystem had been carefully tended for centuries by Native peoples, who used managed burning to create clearings among towering, fire-adapted trees. Early explorers recorded extraordinary plant and animal biodiversity in a dense, mature silvan landscape. But by 1820 the forest was facing rapid clearing for settlement, agriculture, and roads, a process that accelerated greatly with the advent of steam locomotives, which initially burned wood for fuel while also lugging timber to distant cities.  

Altogether, nearly one-third of the world’s forests have been lost over the last 10,000 years, with forest cover on habitable land shrinking from 57 percent to 38 percent (forests formerly covered 40 percent of Earth’s total land surface, while today they cover 30 percent). The pace of loss accelerated greatly in the last century, with half of all historic deforestation occurring after 1900.


Figure source: OurWorldInData.org, (CC-BY) Hannah Ritchie and Max Roser, 2025.

Although global deforestation rates peaked in the 1980s and later slowed, they remain high, especially in tropical regions, due to logging and agriculture. But, in the current century, a new threat is emerging that could result in the loss of over half the area of the world’s remaining forests by 2100 from wildfire, drought, flood, and heat stress. Forests as Climate Victims Recent research suggests that climate change will have a range of impacts on forests, most of them destructive. It’s widely understood that tree species that have adapted to conditions prevalent over the past few thousand years will need to migrate toward the poles to thrive in a warmer world. However, forests are lagging up to 200 years behind the necessary rate of migration, raising the prospect of widespread forest collapse. Further, the composition of most forests is shifting toward faster-growing, less resilient tree species. A 2020 study showed that forests are becoming younger and shorter—largely due to the climate crisis but also to the human introduction of non-native trees—and this is reducing their overall carbon storage capacity. They’re also becoming simpler, populated by fewer species. Unfortunately, the species that appear to be losing out are ones that grow more slowly and anchor forest ecosystems, supporting diverse webs of life—especially in the tropics, where biodiversity is highest. When fast-growing trees dominate a forest, storms, drought, and pests can cause more damage. Slower-growing, long-lived trees often have deeper roots, sturdier trunks, and denser wood that help forests resist drought and pests. Further, pollinator insects, birds, and mammals are often adapted to slow-growing trees.

Finally, due to climate change and shifts in forest composition, wildfires are getting worse, currently burning more than twice as much tree cover annually as they did 20 years ago. Carbon emissions from forest fires increased by 60 percent globally between 2001 and 2023, with boreal forest emissions nearly tripling, according to NASA research. Particularly in the tropics, forests are facing tipping points where they may become carbon sources rather than sinks due not just to wildfires but also intensified droughts and reduced soil carbon stability.  Forests as Climate Heroes As all this is happening, we are learning more about forests’ role in stabilizing the global climate. Trees provide shade, cool the local environment through transpiration, moderate global water cycles, and remove carbon from the atmosphere. Through these four benefits, forests offer perhaps our best realistic hope for minimizing the climate crisis. You’ve surely noticed that it’s cooler to sit under a tree than to stand in blazing sunlight. That’s why cities with more trees enjoy lower surface temperatures in summer months. Forests provide the same service on a vast scale, and as forests are cut, local surface temperatures rise significantly. Forests also cool the land through transpiration. Trees draw water from the soil up to their leaves, where it evaporates. Much of the energy needed to evaporate the water comes from heat in the air; as that heat energy is transferred to water, the air cools. This is the same mechanism that makes you feel colder when you step out of a pool. A single tree in a tropical forest can cool local land and air equivalent to the work of two household air conditioners, evaporating up to 150 gallons of water per day. Forest canopies cover a large surface area, which can evaporate millions or billions of gallons a day. When forests in tropical regions are cut down, this evaporative cooling stops, and the land surface warms. This is happening with the enormous Amazon rainforest, and the consequences will be global. Borneo is seeing a similar pattern. In 2018, researchers surveyed people in 477 villages, and found that the villagers clearly understand that deforestation on the island is resulting in hotter temperatures that threaten the health of their families. With all that evaporation going on, you might think forests would have a net drying effect on the surrounding land. But the opposite is true. Forests create their own rain and fog, regulating water cycles to keep soils moist year-round. Meanwhile, tree roots minimize erosion and provide habitat for beneficial soil organisms. Forests reduce weather extremes (including droughts and floods) and maintain conditions that benefit not only trees themselves, but the entire web of life in sylvan ecosystems.

Trees also remove carbon and store it in their roots, trunks, branches, and leaves. Altogether, the world’s forests store roughly 860 billion tons of carbon in their biomass, deadwood, litter, and soil. As a critical carbon sink, they actively absorb a net 7.6 billion tons of CO2 annually—about 1.5 times more than the United States emits each year. The authors of a recent meta-study offered this summary: “The substantial body of research we review reveals that forest, water, and energy interactions provide the foundations for carbon storage, for cooling terrestrial surfaces, and for distributing water resources. Forests and trees must be recognized as prime regulators within the water, energy, and carbon cycles.”  The Intelligence and Resilience of Trees As we’re learning more about the vital role trees play in maintaining stable, habitable environments, we’re also beginning to appreciate trees’ intelligence, sociality, and resilience. Research reveals that trees form complex, interdependent networks that enable them to both cooperate and compete. While some scientists maintain that “intelligence” implies conscious thought in brains—which plants, of course, don’t have—Canadian forestry scientist Suzanne Simard argues that the complex, agency-driven behavior of trees constitutes a form of intelligence. Trees express this intelligence through communication, memory, and resource sharing. Trees communicate both below and above the ground. Under the soil surface, they connect their roots via fungi, allowing them to share nutrients. Research suggests this network (the “Wood Wide Web”) can, in some cases, transfer nutrients from older “mother trees” to younger seedlings. Trees also send chemical and electrical signals root-to-root, prompting neighbors to prepare for threats like disease or drought. Above ground, trees release volatile organic compounds (VOCs) into the air when attacked by pests such as caterpillars, signaling nearby trees to strengthen their defenses by producing tannic or phenolic compounds. In addition to communicating, trees sense their environments in ways we’re just beginning to understand. Recent studies suggest trees can react to the sound of running water or the vibrations of pollinator wings. Simard and German forester and author Peter Wohlleben posit that trees can learn from past experiences, such as droughts, and make decisions about resource allocation. Dying trees even seem to know the future: before they expire, they warn their offspring to start making new root connections. Much of this recent forest research focuses on the role of large, old trees acting as hubs in arboreal networks, nurturing young trees and maintaining forest stability. Simard contends that mother trees are anchors of forest communities, and are remembered by other trees after they die. What We Can Do for a Forested Future The intelligence of trees creates and maintains resilient arboreal communities. If we humans are to survive, we must similarly build and restore our own resilient communities. We can learn from trees as we continue to benefit from them. But for that to happen, humanity must begin treating the forest as more than just a monetarily valuable resource. Given the current accelerating rate of destruction, our top priority must be to defend native forests and the mother trees that anchor them. Globally, the most dedicated forest defenders are Indigenous peoples, who according to some estimates currently protect 80 percent of the world’s biodiversity. In the Brazilian Amazon, Indigenous communities’ efforts to assert collective land rights have reduced deforestation by 66 percent. In Sumatra, Farwiza Farhan (co-founder of HAkA, an NGO protecting the Leuser Ecosystem) has confronted illegal palm oil companies to protect old-growth forests. In Zambia, Honorary Forest Officers (HFO) protect the Imanda mushitu forest from illegal logging and inspire the next generation of conservationists. In Nigeria, Forest Guards risk their safety to stop poachers and loggers, offering a first line of defense against forest destruction. Beyond forest defense, our next priority must be reforestation. While major global reforestation projects like Africa’s 8,000km Great Green Wall and the Bonn Challenge (aiming to restore 350 million hectares) attract significant funding, community-driven efforts in the Amazon, Madagascar, and Indonesia often achieve their goals with lower cost; such efforts depend on the work of dedicated campaigners like Leah Namugerwa of Uganda, a youth climate activist. However, it’s essential to consider where we should be planting trees in a warming world. This can start with forecasting the likely future climate regime for areas targeted for reforestation efforts and then planting trees that will thrive in that climate; in effect, helping forests migrate. A 2026 study found that strategic planting with future climate considered, such as in Canada’s boreal forest edge, could significantly boost carbon removal.  More thought must also be given to the kinds of trees being planted. Commercially driven reforestation efforts often focus on fast-growing species that yield straight, easily milled timber. However, this results not in a forest ecosystem but in a tree plantation. In recent decades, tree plantations have been growing in total acreage while native forests have been shrinking, though native forests are far better for climate change remediation and maintenance of biodiversity. We should be planting more slow-growing native trees, in mixed patterns that reproduce healthy, self-sustaining ecosystems—and that requires creating habitat for animal species that have evolved with native forests. Like all other organisms, trees depend on relationships: with other plant species, and with pollinators and seed spreaders. Holistic reforestation programs in Nevada, Oregon, and Idaho, as well as proponents of “mini-forests,” are taking steps in this direction. In 2023, about 84 billion dollars were spent globally on reforestation and forest protection. This year, roughly 700 billion dollars are likely to be spent just on AI data centers. Humanity would get by just fine without AI, as we have done for 99.999 percent of our history. But without trees, humans may not persist. The future of forests and that of humanity will be intertwined, like our pasts. The decisive question facing us is: Will it be a balanced relationship that can endure, or an extractive one doomed to failure?

123. The Evolution of Modernity

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by Richard Heinberg

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  • The human world of the early 21st century is dominated by science, cities, and high technology. However, both our modern way of life and our way of thinking about the world sprang up only within the past several centuries. Today’s humans are biologically the same as people who lived 10,000 years ago; but our current habits, expectations, and beliefs are almost entirely tied to machines, infrastructure, energy sources, and artificial materials that have only recently come into existence. Compared to our hunter-gatherer forebears, we might as well be from another planet.

We take modernity for granted, as the fish presumably takes for granted the water in which it swims. But our own metaphorical water is increasingly troubled. Survival-level problems are appearing with more frequency and intensity, including climate change, resource depletion, the disappearance of wild nature, and the toxification of the biosphere. If society cannot extricate itself from this worsening turbulence, our species may not persist much longer.

What’s outside the fishbowl we call modernity? And how did we humans get into it in the first place?

Progress or Polycrisis

Most people who live in industrialized nations now believe that humans are superior to the rest of nature. It is assumed that by using science and reason, along with giant helpings of technology, we can banish scarcity and ignorance. Modernity is thought to be the implicit goal of billions of years of biological evolution. And some of us imagine techno-humans to be the seed pods resulting from this great flowering, capable of spreading life and intelligence into the rest of the universe.

There have long been critics of modernity such as Chief Seattle (“When the green hills are covered with talking wires and the wolves no longer sing, what good will the money you paid for our land be then.”). However, in the last few years a critical discourse about modernity has emerged in books, blogs, and academic literature, notably in the works of three authors—Vanessa Andreotti, Tom Murphy, and Dougald Hine (more names deserve mention, including Robin Wall Kimmerer, Daniel Quinn, Anna Lowenhaupt Tsing, Jeremy Lent, and Joanna Macy, but the aforementioned three will serve our immediate purposes).

Vanessa Andreotti, in her book Hospicing Modernity: Facing Humanity’s Wrongs and the Implications for Social Activism, focuses on the modern mindset, which she characterizes as a collection of “expired stories” from which spring racism, colonialism, and wanton destruction of nature. She contrasts this modern mindset with Indigenous ways of knowing, which not only made societies more sustainable, but gave their members a sense of organic connection with their surroundings and with one another.

Tom Murphy, author of the blog “Do the Math,” sometimes describes himself as a recovering astrophysicist. In essays dating back to 2011, he shows that techno-solutions to climate change and other survival-level predicaments aren’t working and can’t work at scale. Murphy has concluded that only a fundamental shift in how humans inhabit the planet can enable our species to continue. While his starting point differs from Andreotti’s, he has come to share the latter’s outlook on modern versus Indigenous human cultures. Note: Murphy recently shared the story of his intellectual journey on the Crazy Town podcast.

Dougald Hine is the author of At Work in the Ruins: Finding Our Place in the Time of Science, Climate Change, Pandemics, and All the Other Emergencies. In it, he explains why he has stopped focusing on climate change in his environmental writing. Although global warming is a survival-level problem, it cannot meaningfully be addressed without engaging in a deep critique of modernity. Like Andreotti and Murphy, Hine calls upon us to reawaken Indigenous attitudes toward nature.

For these authors, modernity is the cause of the current polycrisis and the impending Great Unraveling. Modernity is likely to comprise a brief and intensely destructive moment in Earth history, because the way we live is unsustainable not just in its details, but in its inherent design. Despite our pretentions and aspirations to be free of natural limits, we humans remain, and always will be, part of nature and subject to it. We pollute and deplete it at our own peril.

Are Humans Great or Terrible?

Implicit in this bifurcation of ways of looking at modernity are two views of Homo sapiens. If modernity is a magnificent achievement, it’s assumed that this is because humans are inherently great and are expressing that greatness through technology. In this view, we humans are more than just clever animals; we are evolving to become gods—as some writers have explicitly claimed.

The critics of modernity describe the current phase of human history not as an expression of intelligence and virtue, but as a cataclysmic mistake: for the sake of momentary comforts, conveniences, and profits, we are generating existential problems that could imperil not just civilization, but planetary life-support systems. One might well conclude from this that humans are terrible.

However, that pessimistic assessment of the worth of our species may be a misreading of both the situation and of the modernity critics. If we consider humans to be animals embedded in ecosystems, then whatever we do is part of nature and evolution. Biological evolution gave us big brains and opposable thumbs. Then cultural evolution via language and toolmaking took over, initiating a rapid self-reinforcing feedback process that has accelerated until the present. Modernity is the first instance in evolutionary history where a species has developed tools and language to expand its range and potential resources, thereby depleting not just its immediate region but global stores of fish, game, trees, soil, and minerals, while overfilling global waste sinks, notably the planetary atmosphere. However, the essential pattern of a species overexploiting its environment, increasing its population until it exhausts available resources and waste sinks, and then dying off, is common in nature. Humans are products of evolution, and whatever qualities drove us to provoke climate change and all the other predicaments of modernity are inherent in evolution itself.

Money, technology, social complexity, and war—human cultural traits that seem to separate us from other creatures—emerged via evolution. Natural selection is a process of improvising and testing; it doesn’t have a goal in mind. Once nature’s improvisation turned in the direction of language and toolmaking, modernity may have become inevitable. While all human groups didn’t follow the path that led eventually to the extreme exploitation that characterizes modern industrial civilization, the existence of even one group with the environmental preconditions, cultural history, and audacity to pursue the path of technological hyper-innovation and empire building made modernity virtually unavoidable. Most other groups were then swept along, first via colonization and later through economic globalization.

While techno-utopians envision humanity taking charge of Earth and then moving on to the stars, critics of modernity, when contemplating the future of our species, are more likely to look for clues in nature. When a species finds a new food source and multiplies, it eventually reaches limits of that food source; its population overshoots a sustainable level and crashes. This overshoot/die-off population cycle is particularly common among invasive species, which often negatively impact native species. However, once invasive species have been around for long enough, they and surrounding native species typically co-adapt—sometimes to the long-term detriment of at least some of the natives, sometimes to that of the invader. If the invaders are predatory, they eventually learn to take only some of their potential prey. If the invaders are prey species, they learn new survival strategies, perhaps including camouflage.

Similar boom-and-bust cycles have happened in human societies. Many societies experienced Golden Ages when resources seemed abundant and when comfort, convenience, and knowledge increased for a significant portion of the population. These Golden Ages were typically followed by Dark Ages of resource scarcity, poverty, and loss of high culture. All that’s different today is that we’ve achieved a global Golden Age based on the use of fossil fuels (which enable us to extract resources in larger quantities and move them longer distances); as fossil fuels dwindle and the consequences of burning them degrade ecosystems, a global Dark Age will likely follow. But its degree of darkness will depend on how willingly and successfully humanity adapts to limits.

Perhaps it’s helpful to think of the historical process of human cultural adaptation to environmental limits in slightly different terms. In the distant past, when a particular human group reached a limits crisis (usually with food), it had two options: indigenize or colonize. To indigenize meant adapting the group’s population size and consumption behavior to levels that could be sustained given existing resources. To colonize meant moving elsewhere, taking over other groups’ resources, or inventing ways to access resources that previously were inaccessible. No doubt circumstances and group history (and therefore mindset) predisposed each group toward one or the other strategy. Modernity marks the historical moment when the colonizers have taken over the whole world. But, having done so, they find themselves in a bind: there’s nowhere else to colonize, the resources held by Indigenous peoples have mostly already been looted, and unexploited new resources (perhaps including thorium or geologic hydrogen) are few and of questionable utility or accessibility. The only real long-term solution is for the colonizers to indigenize.

Evolution, Big Mistakes, and Human Agency

Critics of modernity are not the first people to question our evolutionary urge to colonize. For millennia, Indigenous thinkers, as well as some philosophers from the world’s dominant civilizations, have offered guidance on how to adapt to limits—psychologically as well as practically. In most if not all cases, the impulse to temper our human urge toward greed and outward expansion arose due to a humbling previous descent into scarcity that came from overharvesting resources.

During the last 60,000 years, humans fanned out across the globe, encountering ecosystems new to them. In each unfamiliar place they encountered, they tended to kill large animals that provided a high return on hunting effort. Many of these animals—including mammoths, mastodons, ground sloths, and three species of camels—were driven to extinction, and people had to resort to harvesting smaller game whose hunting required more work. Gradually, people who stayed in one place for many generations learned to leave enough plants and animals unharvested so that these species could reproduce and flourish.

Anthropologists Colding and Folke, in their studies of Indigenous peoples, found six kinds of tribal taboos regulating the harvest of vulnerable species. These are “segment taboos,” which forbade individuals of a certain age, sex, or social class from harvesting a resource; “temporal taboos,” which banned the use of a subsistence resource during certain days, weeks, or seasons; “method taboos,” which restricted overly efficient harvesting techniques that might deplete the stock of a resource; “life-history taboos,” that forbade the harvesting of a species spawning or nesting; “specific-species taboos,” which protected a species at all times; and “habitat taboos,” which forbade human exploitation of species within particular reefs or forests that served as biological reserves or sanctuaries.

Indigenous people weren’t automatically eco-wise simply because they were pre-modern. They inhabited worlds that had already been over-exploited, resulting in conflict and privation. The lessons of moderation were hard-won and eventually resulted in locally rooted cultures that assumed responsibility for the maintenance of nature’s balance, that made modest demands on ecosystems, and that recycled everything. Some indigenous societies, such as the Aboriginal peoples of modern-day Australia, developed practical, tested knowledge for living in balance with the more-than-human world that persisted for tens of thousands of years.

Some later colonizers likewise achieved ecological wisdom after having devastated their environments. By roughly 500 BC, ancient Greece was deforested and its topsoil was largely depleted. This was the context in which Greek stoic and cynic philosophers arose, advising a simple, peaceful, and virtuous life in harmony with nature (Epicurus: “Poverty, brought into conformity with the law of Nature, is great wealth.”).

Among the world religions, Buddhism has perhaps the most ecological message: other organisms, like us humans, are on the path to enlightenment, so don’t harm them if you can avoid doing so. Practice self-restraint and curb your appetites. Many environmentalists are attracted to Buddhism (which, despite its non-violent rhetoric, was spread throughout southern Asia via holy wars). Again, the context in which this religion of moderation emerged was ecological devastation. Anthropologist Marvin Harris offers this summary:

“By 600 BC, . . .  the population had risen into the millions, towns and cities had sprung up, the entire Gangetic plain had become deforested, there was a shortage of pasture and fodder . . . and warfare was incessant.”

Today, as environmental devastation descends upon us all, ecological wisdom is again germinating—this time among climate change activists, students of ecology, and, unsurprisingly, people learning from Indigenous ways. Perhaps today’s critics of modernity are evolution’s growing tip, exploring a way toward the recovery of humanity and the biosphere.

We modern people prize boiled-down bromides we can easily recall, and we like to think we’re in charge of our fate. An honest critique of modernity discourages both mental tendencies. Details matter, the world is rife with nuance, and our agency is limited. However, if there is one simple bit of advice we might do well to remember, it’s this: stay humble. Much of what we think we know is wrong, and the rules of the game of survival are changing. The colonizing rules, which seemed to work so well for a while, at least for some, have propelled us into the evolutionary cul-de-sac called modernity. Going just a little further toward that dead end, via still more economic growth and technological innovation, will provide no solution. A response that reaches back to our very self-identity as humans is required.