Excerpted from “Minding the Climate: How Neuroscience Can Help Solve Our Environmental Crisis” by Ann-Christine Duhaime, t he Nicholas T. Zervas Distinguished Professor of Neurosurgery at Harvard Medical School and former director of pediatric neurosurgery at the Massachusetts General Hospital.

From cave paintings to “Beowulf” to classical symphonies to the Mars Rover to decoding the human genome, the human brain has an extraordinary track record of creativity and problem-solving. We evolved with unparalleled ability to identify and successfully tackle challenges to our survival, an advantage that underlies our unique ability to inhabit and exponentially populate every corner of the earth.

But our extraordinary brains don’t solve all problems equally well. Our evolutionary history equipped us to perceive, prioritize, and find solutions for some kinds of problems more easily than for others, and there are some for which we are ill-suited novices. In all our pursuits, we are guided by an extraordinary internal mechanism that evaluates, second to second, our actions in relation to a shifting panoply of human rewards. This complex mechanism, honed by millions of years of history but flexible by nature, assigns value to our choices and guides us with electrochemical currencies that are exquisitely designed under the influence of evolutionary pressure to be fleeting. It is the understanding of that mechanism and how it intersects with our human decisions relevant to climate change that we will pursue in this exploration.

Science, industry, technology, politics, economics, extractavism — climate change is about all these things and many more. It is as wide as the world and as deep as history in its causes and in its scope. But ultimately, climate change is about human behavior. The human brain represents both the cause and the potential solution to this “grand challenge.” Scientific details of predictive models can be debated in this unprecedented arena, but the reality of climate change and the pre-eminent role of human activity are widely accepted around the world. Environmental decline gravely affects society’s most vulnerable populations already; it is well along in its inexorable dismantling of ecosystems and populations worldwide.

If our brains are so able and adaptable, why, then, is it that on average we struggle to acknowledge and respond effectively to an accelerating environmental dismantling, one that comes with critical time limits, and has been recognized as steadily worsening for over half a century? The cause of the problem is not obscure: High-income industrialized countries contribute more than anyone else in the world to global greenhouse gas accumulation and other aspects of environmental decline via ever-increasing consumption. Despite this, our individual and collective behaviors have been slow to change in response to the increasingly urgent consequences of the way we live and the decisions we make individually, institutionally, and politically. To understand the paradox of our inactivity in this outward-facing, global-scale problem of climate change we need to look inward, at how our brains work. Within these insights — about how the human brain perceives and approaches specific types of challenges, particularly those requiring a re-evaluation of choices guided by the human reward system — lies potential for change, and some cause for hope.

Technological fixes, including new energy sources and engineered mitigation approaches, clearly are essential to slow the acceleration of greenhouse gas accumulation; these are the focus of intense efforts in research laboratories around the world. Prioritizing and adopting these novel technologies will require overt and large-scale changes in behavior, including revolutions in infrastructure, institutions, and economies. But changing large-scale institutions will take time, and based on the current best climate change predictions, unlimited time is what we don’t have before we make essential changes in our behavior.

During the critical decades in the first half of the 21st century, before we can overhaul our physical and economic infrastructure so that technology can bail us out, keeping climate change within a range that has a chance of averting the worst catastrophic synergies requires a bridge to decreased consumption that can be adopted quickly, widely, cheaply, and easily. A significant body of research suggests that relatively straightforward measures that already exist to reduce waste, to substitute different behaviors for accomplishing tasks in the residential and workplace spheres, and to consume less in specific categories by those in high-income countries may be the most effective — and perhaps the only realistic — way to bridge this carbon output gap. It won’t solve the problem, say these scholars, but instituting such measures can result in sufficient climate stabilization to maintain a relatively resilient and recognizable world. Furthermore, these changes don’t need to drastically reduce our quality of life. But they do require change.

Climate change in particular plays to our weaknesses. Much has been written about our difficulties in perceiving climate change, due in part to inconsistencies in the information we receive and also stemming from the well-studied tendency to “discount” events that are perceived to occur far in the future or in geographically distant places. These heuristic errors, when we “shortcut” complex decisions involving uncertainty to make them easier to address, have played an important role in our quandary. There are additional key features of climate change for which our inherited neural equipment has limited perception. This occurs because, in short, from the brain’s point of view, the behaviors required for this first-of-its-kind problem just aren’t very rewarding .

A strong case can be made that we have faced other big challenges that required major overhauls of the social order and behavioral norms. In the history of the United States, attitude and behavior changes in response to industrialization, racial inequality, and women’s rights spread socially in fits and starts, stumbling gradually toward a critical mass supporting a new normal. Global pandemics have spurred dramatic changes in daily life, as well as remarkable pivots in targeted science and technology. Though these problems are difficult and still nowhere near approaching remission, they have features that we are equipped to recognize, and we generally can link responsive individual, moral, and political actions to potential solutions. For climate change action, discounting and other psychological shortcuts slow our progress. But barriers also arise from a discordance between how our brains were designed by evolution to weigh decisions based on survival pressures during a different time in history, compared to the behavior changes required for this unique crisis today. We can take action to avert the worst possible outcomes, but the solutions, especially in the time frame required, do not come naturally to us. Our brains may be more readily equipped to make us feel effective and positive by sending money to flood victims than we feel by engaging in the kinds of behavior changes that would help prevent the cause of their suffering. Still there may be ways to pick up the pace if we know why these changes are especially difficult and can implement strategies proven to make them easier.

But change is not purely rational. Why don’t people seatbelt their kids? Why don’t all motorcyclists wear helmets? Why don’t addicts just quit? Why can’t we do what we need to do to stop destroying our planet while we still have the chance?

Many fields of study have tried to answer questions about difficult behavior change, from public health, economics, and psychology to government and policy. For climate change, making different decisions with differently weighted priorities is required not just at the level of individuals in their private and work lives but also in their leadership and political roles and as influencers of contagious social movements. It requires change in prioritization for people making decisions as managers of companies, planners in industry, financiers and economists, media influencers, voters, officeholders, and policymakers. But regardless of the scale of influence, the basic unit of behavior change happens person by person.

So here we focus our attention on the neural mechanisms by which the recipient of new information or new circumstances changes the calculations by which decisions are made, to better understand what elements go into change, and which tend to have the greatest influence, at the individual or group scale. While many researchers have chronicled the reasons people have trouble perceiving the importance of climate change, a smaller number have studied what works best to actually change behavior to facilitate choices with a more direct impact on the climate problem itself. Even fewer have applied a neuroscience lens to understand whether the behavior changes needed may be facilitated by working with, rather than against, the brain’s functional design. What is it about how the brain is designed to work that makes this problem difficult for us, and how can we best use that information to help move us in a more effective direction?

Much of the research on behavior change relevant to the environment comes from the field of psychology, with investigators often working in concert with economists and researchers from other disciplines. While classic psychology experiments study behavior observed within a specific time and circumstance, related and overlapping approaches in neuroscience investigate how the nervous system works at the level of cells, molecules, and genes. Psychology describes behavior in specific situations, while neuroscience provides complementary insights into how consistent or malleable behavior may be, based on the plasticity and adaptability inherent in the brain’s very design. Whether shifts in behavior are likely to be an effective tool in the climate change battle can be answered only by knowing the environmental impact of specific behaviors, the flexibility of people to make different choices, and the likelihood that enough people might be influenced to change their behavior in a particular direction.

Neuroscience historically has not turned much of its attention to climate change, but the field is steeped in the study of behaviors that are relevant to this problem. Clinicians practicing in neuroscience-based specialties deal routinely with disorders that involve adaptive and abnormal goal-directed behaviors, the influence of experience and neural plasticity on brain function, and other manifestations of the intersection of brain and behavior. Building on painstaking work in basic neuroscience, they treat drives that are “out of balance” — excessive in addictions, dysfunctional after damage to motivation and reward networks — and require strategies for behavior change. As one striking example, patients with Parkinson’s disease whose medication doses or deep brain stimulators to control tremors are turned up too high may become compulsive gamblers or shoppers. These disorders shed light on the circuitry and modulation of healthy and “pathologic” brain networks that influence the drive to consume.

In other contexts, clinicians observe daily the amazing resiliency of the human complement of drives and motivations honed also by millions of years of nervous system evolution. Humans are rewarded by agency — the sense of accomplishment afforded by successfully completing a task. But perceiving agency from climate change action is a more difficult neural challenge.

Other brain-mediated rewards are similarly critical to the human story. Social rewards are among the most powerful ever identified. And children are especially rewarded when fulfilling their innate drive to explore, learn, and experience. Even after major surgery, what children want most is to go to the playroom and seek out toys; distraction by novelty (most recently, by iPads in the recovery room) has been shown to be more effective than narcotics for reducing pain. There are data demonstrating that exposure to nature is rewarding but that this reward differs in fundamental ways from that of acquisition and consumption. We will explore these neural traits in more detail to learn what factors facilitate different types of behavior change, including those that might have environmental consequences.

This book arose from a particular journey through the topic of environmentally relevant behavior from the perspective of a brain-focused clinician-scientist, specifically in the field of neurosurgery. Not surprisingly, people in this field tend to think everything is about the brain — but is that useful? From a brain-centric point of view, behavior-related problems like climate change reflect the design of the equipment we use to interact with and influence the world. Solutions may be enhanced by taking into account an explosion of new insights from neuroscience on how this equipment works at a fundamental level, and how it is or isn’t suited to the various responses at hand.

From the lens of neuroscience, decisions are arbitrated by the brain’s reward system, with inputs from a wide variety of internal and external influences. The brain’s decisions and priorities are not predetermined by genes or some unalterable program, and they differ from person to person. Our neural equipment is exquisitely designed to respond to changing conditions — but with certain predispositions and limitations. Understanding the evolutionary design and workings of the brain’s reward system in decision-making can help us understand the choices humans tend to make in the environmental realm — and most importantly, how malleable these choices may be. While we have some common tendencies to behave in certain ways, we also are engineered to be different from one another by design, as this works best for societal problem-solving and survival. In addition, our neural design includes the trait of being highly adaptable to specific types of new circumstances — though there are some strategies that can be called on to make us adapt more easily. Which behaviors contribute the most to environmental harm? What works and doesn’t work to change behavior, and why? How fixed or flexible is the decision-making apparatus of the human brain? How does the way we live in current times intersect with our inherited equipment to make things even worse? And finally, if the reward system is an important mediator for behavior affecting climate change, we should be able to create a test case for this hypothesis. Specifically, can we successfully influence decision-makers at an institutional level to make pro-environmental behavior more likely, by making it more rewarding?

We have gotten out of fixes in the past with ingenuity and technology. In pandemics, epidemiologists talk of “flattening the curve” — slowing things down enough so that worst-case scenarios don’t overwhelm our capacity to cope. We appear to be caught in a similar time crunch to change our behavior over decades, in the hope of giving science and technology, politics, and economics some breathing room to find more long-range solutions, considering the time it will take to get individuals and governments to cooperate and institute large-scale changes. But even on smaller scales, behavior change is hard, and we need all the insights we can bring to the problem.

Published by Harvard University Press. Copyright © 2022 by the President and Fellows of Harvard College. Used by permission. All rights reserved.