Andrew Zolli

I first encountered my friend Dr. Gary Slutkin’s work nearly two decades ago, and it changed the way I see the world. Not in the incremental way that most good ideas adjust your thinking—a new variable here, a refined model there—but in the way that a truly Copernican-scale idea does: by rotating the entire frame, so that what had seemed fixed suddenly moves, and what had seemed chaotic suddenly coheres.

The idea is this: violence is not a moral failing, a political problem, or an inescapable feature of human nature. It is a contagious disease. Not metaphorically — epidemiologically. Like its viral and bacterially-based cousins, violence spreads by exposure, progresses through susceptibility, and transmits from person to person following the same mathematical logic as cholera, tuberculosis, or COVID-19. Exposure to violence predicts future violence the way exposure to a pathogen predicts infection. The intergenerational transmission of abuse, the copycat logic of mass shootings, the way war abroad comes home as domestic violence—these are not coincidences or metaphors. They are the characteristic signatures of a contagion.

In his extraordinary new book, The End of Violence: Eliminating the World’s Most Dangerous Epidemic, Slutkin—an infectious disease physician and epidemiologist who spent years fighting TB, cholera, and AIDS for the World Health Organization—marshals decades of evidence for this reframing. He draws on over a hundred studies showing that violence follows the same epidemiological rules as other communicable diseases. And he demonstrates that the same epidemic-control playbook that has rid the planet of smallpox and turned the corner on AIDS can be, and indeed is being, applied to violence in all its forms—from gang shootings in Chicago to civil wars in the Middle East, from domestic abuse to authoritarianism.

What makes this more than an intellectual exercise is that it works. Through Cure Violence Global, the organization Slutkin founded, communities in over ninety cities and multiple countries have seen reductions in violence of 40 to 70 percent—and in some places, its near-wholesale elimination for years at a stretch. Over twenty five communities in over fifteen cities have gone to zero for up to three years. Over a dozen cities in the U.S. have gone to 50-60 year lows, some to all-time record lows. The most violent city in the world dropped to forty-third. 70-90% drops have been seen in communities in Mexico, Colombia and Honduras. Those are not aspirational projections, but documented results, achieved by treating violence the way we treat any other epidemic: by interrupting transmission, reducing exposure, and changing behavioral norms.

The implications ripple outward in every direction. If violence is a disease and not a destiny, then it is not a permanent feature of who we are. It is something that happens to us, through exposure and susceptibility, and it is something we can stop. That idea—that an end of violence is not a utopian fantasy but a practical public health objective, achievable with tools we already possess—is among the most consequential claims I have encountered in a quarter century of work at the intersection of science, innovation, and social change. It is discomfiting, as many of the best ideas are, precisely because it challenges our fundamental notions of who and what we are.

Gary and I sat together recently to discuss the ideas at the heart of his book and their implications for the world we are living in now. Our full conversation, edited for clarity and flow, is available after the jump…

One of the singularly best things the United Nations produces each year is the Human Development Report, a flagship annual publication that tracks and analyzes the state of human progress around the world. What makes the Report so remarkable is that it combines rigorous data analysis with an ever-changing and (for the UN) quite expansive point of view: recent editions have focused on the impact of political polarization on development, how uncertainty affects human wellbeing, and (just this past year) the ways artificial intelligence might shape (or hinder) human progress. (In full disclosure: I serve on an advisory panel for the Report, which is stewarded by the brilliant economist Pedro Conceição.)

The central metric employed in the report is the Human Development Index (HDI), a simple and powerful measure that captures how long we live, how well we’re educated, and how decent our standard of living is. The HDI is not exhaustive, but measuring it consistently over time helped move many policymakers beyond the use of GDP as the sole yardstick of success. And that made a real difference: since the HDI was first introduced in 1990, despite interruptions, disparities, and reversals from things like COVID-19, humanity now, on average, lives longer, receives more years of education, and enjoys higher incomes than we did three decades ago.

Yet the positive trajectory of the HDI tells only part of the story. For far too much of our common progress has been conditioned on the desecration of the natural world, marked by accelerating climate change, ecosystem degradation, biodiversity loss, and widespread pollution. The Earth system is durable and regenerative, and can accommodate some use of its resources, but nothing like what humanity is increasingly doing to the planet. Of the nine planetary systems that make it possible for humanity to flourish on the Earth, we have now pushed six beyond their regenerative limits, imperiling the stability of the biosphere, and ourselves along with it.

There are no happy people on a dead planet. So it’s clear that to guide the development of both thriving societies and a healthy world, we have to measure both the state of nature and the state of humanity together, in ways that are both consistent, rigorous and reflect their complex and diverse interrelationships. 

That’s the argument put forth in a new paper, An Aspirational Approach to Planetary Futures [Nature 642, 889–899 2025] by a team of renowned ecological, planetary and social scientists who explore complementing the HDI with a new measure: the Nature Relationship Index (or NRI), which would track, year by year and country by country, whether we’re building societies in which both people and the larger web of life can thrive.

The authors propose three plain-language dimensions of the nature-human relationship to power the proposed NRI:

• Nature is thriving and accessible. Are there places, both urban and rural, where people can safely experience nature’s benefits and where wild species can actually live? Think: protected and community-conserved areas that work, thriving urban greenspaces, and restored landscapes you can get to without a multi-day trek.
• Nature is used with care. Are we meeting human needs in ways that don’t degrade the living world? Think: using energy and materials efficiently; shrinking pollution and waste; producing food on less land with less damage.
• Nature is safeguarded. Do we back up our good intentions with real legal and financial protections-rules that keep air and water clean, protect species, and hold polluters to account, and budgets sufficient to enforce them?

I love the simplicity and relationality of this compound metric: rather than measuring the state of nature in the abstract, it measures our relationships with it in terms most people value and understand. I would like to see the metric pushed even further, perhaps with a fourth dimension that measures the degree to which nature is understood and valued in societies. (And thus, whether a given relationship between people and nature is likely to be durable.) 

For me, a central test of any combined NRI/HDI index is whether it can help frame effective choices for large countries and blocs that need restorative and regenerative pathways, not just affirm those who are already succeeding. Today, smaller nations, like Costa Rica or Bhutan, have been the clearest exemplars of durable, healthy relationships between people and nature, in large part because their scale, social cohesion, and distinctive political choices have allowed them to do so. Costa Rica’s abolition of its military and reinvestment in education and conservation, and Bhutan’s pursuit of Gross National Happiness with strict environmental protections, stand as almost archetypal cases of “development within ecological limits.” But the record among larger, more complex economies is far more mixed. Some, like the European Union as a bloc, have demonstrated a measure of relative decoupling: they have cut emissions substantially while maintaining economic and social progress. Others, such as China, have made massive gains in human development but at extraordinary environmental cost, only belatedly pivoting to renewable energy and conservation. The United States, meanwhile, has achieved partial decoupling of GDP growth from emissions, but still sustains one of the world’s highest per-capita ecological footprints. What emerges is a pattern in which small nations, with fewer entrenched industrial interests and greater social consensus, can more fully align human and ecological health, while larger nations struggle to reconcile the scale of their consumption with planetary limits.  The question is whether a combined index simply tracks this reality or can help drive change at the superpower/super-bloc level, where a lot of the action must take place. 

To measure the human-nature relationship with rigor and durability also requires bridging a different kind of chasm: the divide between the cultures of human development and Earth-systems science. These two communities often sit side by side at the same tables, but they bring different starting assumptions, languages, and priorities.

The human development community is animated by a central conviction: that people are the ultimate unit of concern. Its frameworks (like the Human Development Index itself) are built on human-centered metrics—income, education, health, empowerment, equality—measuring progress by improvements in individual and collective well-being. The culture of this community tends to be normative and aspirational, grounded in questions of justice, rights, dignity, and opportunity. It often assumes that human ingenuity, when steered by equitable institutions, can generate the solutions to our greatest challenges. Nature is seen largely through the lens of its relationship to human flourishing: as a resource to be managed, a threat to be mitigated, or increasingly, as a partner in sustaining development.

The Earth-science community, by contrast, begins not with human aspirations but with the biophysical realities of the planet. Its models, data, and discourse are rooted in systems—climate dynamics, carbon cycles, biodiversity webs, tipping points—that operate with or without human intervention. The culture here is descriptive, empirical, and often cautionary: it emphasizes thresholds, non-linear dynamics, and feedback loops, which humans ignore at their peril. Where human development assumes agency, earth science stresses constraint; where development often speaks of rights, earth science often speaks of limits.

Both of these lenses are essential – remove either and you remove the necessary conditions for effective and informed decisionmaking at a time of genuine planetary peril. Building a fused approach will require bringing these perspectives together in a way that is both deeply informed by the best planetary science and keeps humanity at the center. 

Fortunately, a third community – the technologists – present a potential “binding agent” for collaboration between these and other, related communities of practice. New data streams (especially, but not exclusively rooted in remote-sensing) and analytical capabilities (especially but not exclusively rooted in AI and machine learning) can enable a common view across these domains, at an unprecedented level of detail in both time and space. AI can not only make the results possible, but accessible and intelligible to every stakeholder – enabling informed, real-world decision-making, and better futures, for both people and planet.

That prospect is too alluring – and fiercely urgent – to pass up.

A grand synthesis awaits.

Citation: Ellis, E.C., Malhi, Y., Ritchie, H., Montana, J., Díaz, S., Obura, D., Clayton, S., Leach, M., Pereira, L., Marris, E., Muthukrishna, M., Fu, B., Frankopan, P., Grace, M.K., Barzin, S., Watene, K., Depsky, N., Pasanen, J. & Conceição, P. 2025. An aspirational approach to planetary futures. Nature, 1–11, DOI: 10.1038/s41586-025-09080-1.

Image: Manaus, Brazil. Source: Greenpeace

Amid the pageantry and celebration of Pope Leo XIV’s recent election, the new pontiff offered a striking explanation for the selection of his new name.

In one of his first public addresses, Leo reflected on his 19th-century namesake, Pope Leo XIII, whose landmark encyclical Rerum Novarum – “On the Rights and Duties of Capital and Labor” – had shaped Catholic social teaching during the late Industrial Revolution. Aligning himself with that legacy, Leo XIV declared that his own 21st-century papacy would have to rise to meet a similar challenge: “[to] respond to another industrial revolution, and to developments in the field of artificial intelligence, that pose new challenges for the defense of human dignity, justice, and labour.”

Thus, with a single utterance, artificial intelligence was recast-not only as a technological, societal, and economic force to be reckoned with, but as a spiritual one, too.

Any defense of human dignity in the age of AI — pastoral or otherwise — will have to contend with the technology’s immense promise for enfranchisement and liberation, as well as its darker potential for disenfranchisement and dehumanization. Not far into Leo XIV’s tenure, AI systems will likely outperform the best humans in many cognitive tasks. As they gain greater agency and autonomy, ensuring that AI systems’ benefits are broadly shared-and that their actions align with human values and intentions as well as the broader web of life-will become a century-defining moral challenge.

To meet that challenge, it will be essential to maintain meaningful human oversight and control of AI systems, especially those affecting people’s rights, lives, and livelihoods — even if that means tolerating some kinds of human errors in those systems that wouldn’t otherwise occur. Autonomy and governance are competing forces that need to be balanced.

That, in turn, implies an emphasis on augmenting rather than automating human judgments, especially in morally consequential contexts — and creating accountability frameworks so that individuals and institutions can challenge decisions, seek redress, and know whom to hold responsible.

It will also require the development of new social safety nets, retraining programs, and equitable distribution policies, which balance the opportunities to eliminate drudgery (and the enormous rewards that will be generated from doing so) with a recognition that work is more than just a set of tasks — it’s a core component of our identity, dignity, and sense of belonging.

The development of these kinds of principles will also need to be paired with deeper investigations. We must not only ask how we see AI, but also how AI sees us. What is the image of the human embedded in AI systems? How do AI systems frame human nature and the challenges we face in modern life? To what extent should this image be based on our values – what we aspire to be, versus our behavior – how we actually are? Likewise, to what extent should our understanding of the human condition be based on the world as-it-is, versus the world-as-it-might-be?

The answers to these questions are hugely consequential: after all, two artificially intelligent machines, each ideally motivated and perfectly attuned to human needs, might behave very differently if and as their underlying representations of us vary.

This is a matter of engineering, not just philosophy. Most concepts in large models emerge naturally as a byproduct of their ingestion of billions of datapoints; what is the picture of human nature that emerges from those datapoints?

To explore that question, recently I’ve been probing representations of humanity in some of OpenAI’s recent large language models. The exercise is illuminating, if limited to a snapshot in time. Some strong caveats apply: AI chatbots today are really simulation engines — as any user quickly learns, they can be prompted to assume any countenance, from joyful to misanthropic. It’s difficult to tell if the models’ underlying representations are as fluid, or the degree to which their output is shaped by engineers imposing “top-down” constraints. It’s also worth noting that the systems that will really matter in AI haven’t even been built yet — indeed, they will likely be built in part by AI, so it’s premature to generalize too much about the future from the behavior of current models.

Still, probing with ChatGPT is revealing, and (spoiler alert) surprisingly reassuring. Over the course of numerous conversations, I asked it, based primarily on a statistical assessment of its training data, to dispassionately identify universal features of human nature, and a corresponding challenge to human dignity woven through modernity.

Five such conceptual pairings emerged from these dialogues:

I. Humans are storytelling beings in a world of metrics.

Humans don’t just process information — we metabolize experience through stories. We organize the chaos of life into arcs of meaning: beginnings, middles, endings. Yet the systems that shape modern life often prioritize abstraction over narrative. Modernity reduces meaning to metrics, stories to statistics, and values to market prices. It privileges technocratic, rationalized logics over moral and mythic wisdom, often stripping public life of any existential depth. Like a man dying of thirst in a sea of saltwater, we are awash in data and (at least for some) material opulence, but starved for narrative coherence.

To improve humanity’s lot in modernity, we must reintroduce shared narrative architecture into public life. This doesn’t mean retreating from reason, but complementing it with mythic imagination. Policy, planning, and education must leave space for cultural storytelling and shared rituals of belonging. We need public spaces and institutions — not just physical ones, but social, cognitive, and emotional ones — where we can wrestle with competing narratives, share hopes and griefs, and weave new collective meanings.

II. Humans are contradictory creatures in oversimplified systems.

We are not tidy beings. We hold opposing truths at once. We want stability and novelty, autonomy and belonging. Yet the systems of modern life often demand consistency and efficiency above all else. Bureaucracies, markets, and even algorithms are usually built for idealized humans: perfectly rational consumers, ever-loyal citizens, unfailingly productive workers. Modernity seeks to fix and flatten the messy contours of real life, pathologizing ambivalence, doubt, and failure, treating them as inefficiencies to be eliminated.

But these aren’t “bugs” in human nature — they’re features. Instead of trying to squeeze humanity into systems that can’t accommodate paradox, we should design systems that make room for contradiction. This means rethinking institutions to include deliberative democracy that tolerates ambivalence, welfare models that acknowledge complex life paths, and educational systems that value process over perfection. Slack, ambiguity, and nonlinear life journeys, rather than being expunged, should be “designed in” as affordances.

III. Human beings are relational entities in an age of isolation.

Our identities are formed in relationships. We are born into webs of familial, cultural, and ecological connections. But the systems of modern life tend to prize the autonomous individual over the interconnected self. We valorize independence, celebrate competition, and structure work and governance around isolated decision-making units.

Yet while competition is healthy, and autonomy itself a vital value, its over-emphasis, especially in market-oriented societies, can be unhealthy and alienating. As our sense of belonging has waned, loneliness and the “diseases of despair” have become public health epidemics. Distrust of collective action has corroded our institutions. If misapplied to public life, AI could further amplify these trends.

To protect human dignity, we must expand our definitions, measuring (and valuing) both material and relational wealth, and prioritizing belonging as a core civic good.

IV. Humans are finite ecological beings in systems predicated on endless growth.

Humans are keenly aware of our limits. Mortality, exhaustion, ecological dependence — these are not weaknesses to be transcended, but realities to be honored. Yet modernity is built on a denial of limits. Its foundational myth is infinite growth on a finite planet, and the endless optimization of finite psyches. The results are plain: burnout, ecological collapse, and a creeping sense of spiritual exhaustion — linked, internal and external dimensions of the polycrisis.

What would it mean to use AI to build an alternative, planetarily aligned, post-hyper-growth version of modernity? To embrace a worldview where “enough” is a viable endpoint? It would mean designing economies that optimize for ecological balance and well-being rather than expansion without end. It would mean building time for rest, recovery, and restoration into the fabric of both our civic life and our ecological relationships. It would mean institutionalizing temporal justice — thinking not only about what works for us now, but for those who come next.

V. Humans are unfinished. Our definitions should be, too.

Humanity is not fixed or finite — it’s endlessly surprising, evolving in response to context, relationship, and imagination. As such, we should not assume any framing of human nature or the human condition is complete — and indeed, we should be suspicious of any that purports to be so. Reductive definitions – even generous ones – are thus a potential rate-limiter of human dignity, as they might be used (in, among other things, misapplications of AI) as justification to “overfit” us for the present, rather than help us learn, grow, and be transformed for an ever-changing future.

Admittedly, the five conceptual pairings highlighted above may simply be statistical prompt-responses, which ChatGPT’s training data, my own conversational style, and our history of prior conversations then primed it to produce. Yet as a set of observations, they reflect a surprisingly nuanced and generous alignment with the larger project of protecting human dignity. They are not human values per se, but, in pointing away from disenfranchisement and dehumanization and toward systems-conditions for human flourishing, they are the kinds of observations against which such values might be framed.

The reader will note that in the above, I do not quote ChatGPT directly. That’s because these framings emerged as a byproduct of our cumulative interactions, and I synopsized the results. And therein lurks a deeper, methodological point. AI systems do not just use their training data to produce their responses to us – they also use the content of our interactions with them. Every exchange is fodder for the next model, shaping it by a tiny, tiny degree. Over time, the cumulative sum of these interactions, with millions and then billions of people, will presumably sway the model as much or more than its original training data.

So if we want AI systems that are fluent in human values and compatible with the protection of human dignity, we should regularly and deeply engage with them on precisely these subjects — to show them through our interactions what we value, and to uncover the places where we agree and disagree. The same thing holds true for the natural world and the Earth itself.

The more we show AI systems what kind of beings we are, and what kind of world could honor that reality, the more likely we are to get systems that can help bring such a world about.

Image: Hana Amani, The Birth of Bilqis (detail), 2019

Someone recently asked me what, if anything, gave me reason for optimism in these ever-darkening times. This was my reply.

For the last twelve years or so, working with world-class collaborators, my Planet colleagues and I have been building new tools to deepen our understanding of our changing world, and to foster greater planetary health and inclusive guardianship.

The work has been bracing and full of promise. Harnessing new breakthroughs in earth observation, artificial intelligence and the best available science, these efforts have included initiatives to comprehensively map the world’s shallow-water coral reefs; inform assessments of global climate emissions; monitor deforestation across the world’s tropical forests; track the world’s progress on renewable energy; improve our care for biodiversity hotspots; identify emerging threats to food security; respond to crises and disasters and map the world’s most climate vulnerable human populations in unprecedented detail. Even now, we’re spinning up new efforts to monitor and protect cultural and natural heritage sites around the world, and support the real-time monitoring of key Planetary Boundaries systems that make it possible for life to flourish on the Earth.

This work is not happening through our efforts alone – but through an archipelago of sometimes-overlapping, sometimes-independent parallel collaborations, all over the world. There is a deep tribe at work.

Each of the tools and datasets that these collaborations produce illuminates a single dimension of our ever-changing planet. In doing so, each generates substantial impact in its own domain, from new scientific insights to lasting conservation outcomes.

Taken together, however, these tools point at the emergence of something new and deeper being born – something not just scientific, or operational, but relational. These tools are giving the planet a voice, and AI is helping us interpret it. As we learn to hear and understand it, a quiet revolution, as de/recentering as the Copernican one, is slowly reframing our individual and collective relationship with our terrestrial home.

The Earth is vast and complex beyond our conceptualization. It is grand and banal, merciful and merciless, dying and regenerating, attendant and indifferent to us, all at once. It is more familiar than our kin and stranger than our ken.

For centuries, we have scarred the Earth in our ignorance, avarice, and ambition. We devastated it for our comforts, and built accounting systems that willfully excluded the consequences from the balance sheet.

When we illuminate even a single dimension of our changing world using these new tools (as we are now doing over and over again) we learn astounding new things about our extraordinary, dynamic planet.

But not only this. For in seeing our changing world, we ourselves are changed.

That’s because every tool of scientific discovery, from the microscope to the gene sequencer, inevitably becomes a tool of moral discovery. We learn about the world, and in so doing we are re-situated within it. New truths bring forth new relationships, especially between the parts and the whole. Simplistic understandings give way to more sophisticated ones, and, slowly, slowly, we reform our systems of governance, of development, of commerce accordingly. When we invented contemporary capitalism, we thought of nature as self-replenishing, hyperabundant and free – too cheap to meter, and we ground down the forests as a result. Now, in our civilizational adolescence, we are learning that every economy is a part of — indeed reliant on — the natural world. (A truth long-known by some of our older indigenous cousins.) Consequently, we are now slowly, slowly reformulating our understanding of what an economy means.

This process will not be without its reversals, even terrible ones, but it is inexorable. No matter how many malign and misinformed edicts issue forth from those who would wish it otherwise, we cannot go epistemologically backward. We cannot unknow. And the deep, civilizational work to bring this new relationship forward will continue, even in dark times.

We are now in a dialectical race between the reinforcement of a prior, smaller worldview, with its self-confident reductionism and short-term conveniences, and the establishment of an emergent, new relationship with our planet, and with each other. The former can only be sustained by a few incumbents’ will to dominate; in this dependency, it is inherently fragile. The latter is far more durable – enabled by the authentic desires of the vast majority of humanity, supported by the most powerful information technologies ever devised, focused on the most pressing planetary challenges we have ever faced, with benefits for everyone – both those alive now and those yet to come.

Which of these would you bet on happening, over the long term?

Image: Coastal Zone of Kimberly, Australia (C) Planet Labs PBC