Existential Risks: What They Are and Why They Matter

Existential risks are not just about large disasters in the near term; they are about threats that could permanently limit or end humanity’s long-term potential. Understanding them is essential if we care about the survival and flourishing of both present and future generations.

What Are Existential Risks?

Researchers use the term existential risk (often shortened to x-risk) for dangers that could either wipe out humanity or irreversibly lock us into a drastically worse future.

• Extinction: Humanity (or its successors) ceases to exist permanently.
• Irreversible collapse: Civilization falls to a level from which recovery to a technologically advanced, flourishing state is effectively impossible.
• Locked-in dystopia: A stable but extremely bad global system (such as permanent totalitarian rule) that we cannot escape.

These risks are a subset of global catastrophic risks—they are global in scale, but also terminal and permanent, affecting all future generations, not just people alive today.

Why Existential Risks Deserve Special Attention

From a moral and strategic perspective, existential risks stand apart from other global problems for several reasons.

• Scale of impact: An existential catastrophe would determine the fate of all future people, potentially foreclosing trillions of lives and achievements.
• Permanence: Unlike temporary setbacks (such as recessions or even major wars), existential disasters prevent recovery or lock in a permanently worse condition.
• Neglectedness: Compared with climate mitigation, public health, or economic policy, direct work on existential risk reduction still receives relatively little funding and attention.
• Irreversibility: Many policy mistakes can be corrected; existential mistakes cannot.

Because galaxies and stars could support life for billions of years, the potential future of humanity is enormous; even a small reduction in the probability of existential catastrophe could have vast expected value.

Ways Researchers Classify Existential Risks

There are several complementary ways to organize existential risks. One influential approach focuses on the type of long-run outcome, while another categorizes risks by their source (natural vs. anthropogenic vs. technological).

By Type of Long-Run Outcome

By Source of Risk

• Natural risks: Asteroid or comet impacts, large volcanic eruptions, or rare cosmic events.
• Anthropogenic risks: Human-caused threats such as nuclear war, severe climate change, engineered pandemics, and misused advanced technologies.
• Structural and governance risks: Failures in global cooperation, value alignment, or institutions leading to long-lasting harmful systems.

Current expert views generally hold that anthropogenic and technological risks are now more significant than natural ones over the coming centuries, because natural baseline risks appear low on annual timescales and we are introducing powerful new technologies rapidly.

Major Categories of Existential Threats

Although the precise probabilities are uncertain, researchers often highlight several clusters of especially concerning risks over the next 100–200 years.

1. Nuclear War and Long-Term Nuclear Winter

Large-scale nuclear conflict between major powers could cause immediate mass casualties and second-order effects such as climatic cooling (“nuclear winter”), food-system disruption, and political collapse.

• Direct impacts: Hundreds of millions of deaths from blasts, fires, and radiation in large arsenals scenarios.
• Climate effects: Studies suggest large quantities of soot lofted into the stratosphere could cool the climate and drastically reduce global crop yields for years.
• Path to existential catastrophe: Combined physical destruction, famine, disrupted governance, and further conflicts could lead to collapse from which recovery is uncertain.

Nuclear war is often classified as a global catastrophic risk that could, in extreme scenarios, rise to an existential level by triggering collapse or secondary disasters that permanently prevent recovery.

2. Climate Change and Environmental Degradation

Anthropogenic climate change is already affecting ecosystems, weather patterns, and human societies.

• Near- to medium-term harms: Sea-level rise, extreme heat, changing precipitation, and increased risk of conflict and displacement.
• Feedback loops: Melting ice sheets, permafrost thaw, and biosphere changes could amplify warming.
• Existential pathways: While mainstream projections typically view climate change as unlikely to cause human extinction directly this century, it could still contribute to existential outcomes via compounded stresses, geopolitical instability, and maladaptive responses (including risky geoengineering).

Environmental damage more broadly—such as biodiversity loss and ecosystem collapse—could also increase vulnerability to other risks, including pandemics and food-system shocks.

3. Global Pandemics and Engineered Biological Risks

The COVID-19 pandemic illustrated how a single pathogen can rapidly affect the entire world. Future biological risks could be more severe, especially if advanced biotechnology enables the deliberate or accidental creation of highly transmissible, highly lethal agents.

• Natural pandemics: Novel zoonotic diseases can emerge from human–animal interactions and globalized travel.
• Engineered pathogens: Synthetic biology might eventually allow small groups to design or modify organisms with greater transmissibility or immune evasion.
• Existential mechanisms: Extreme pandemics could cause near-extinction, or trigger cascading failures across food, energy, and governance systems.

Many experts argue that improving biosecurity, surveillance, and governance of dual-use research now is critical to reduce emerging biological existential risks.

4. Transformative Artificial Intelligence (AI)

Artificial intelligence systems are advancing quickly in capability. Some researchers focus on transformative AI: systems that could automate a large fraction of cognitive work or significantly reshape civilization.

• Misaligned objectives: Powerful AI systems pursuing goals not fully aligned with human values could lead to unintended, large-scale harm.
• Loss of control: Once AI systems can design and deploy more capable successors, humans could lose meaningful control if safety and alignment are not solved in advance.
• Concentration of power: Advanced AI might enable highly effective surveillance or coercion, raising the risk of permanent totalitarianism.

Because AI could amplify both our ability to solve problems and our capacity for harm, it is widely regarded as one of the central emerging existential risks of this century.

5. Global Governance Failures and Permanent Dystopias

Some existential threats emerge less from a single technology and more from how societies are structured and governed.

• Permanent totalitarianism: Stable, globally enforced oppression, possibly supported by advanced surveillance and control technologies.
• Norm erosion and value drift: Future societies might adopt norms that tolerate severe suffering, oppression, or exploitation on a massive scale, and embed these in lasting institutions.
• Coordination failures: Inability of states to cooperate on shared risks (e.g., arms races in unsafe technologies) can magnify the risk that one actor’s error or misuse has global consequences.

These scenarios can result in existential outcomes even without human extinction, by locking in a civilizational trajectory that is permanently and severely worse than what is possible.

6. Natural Cosmic and Geophysical Catastrophes

Earth has experienced massive impacts and geophysical events in the deep past, including the asteroid impact associated with the extinction of the non-avian dinosaurs.

• Asteroid and comet impacts: Very large impacts could cause global firestorms, long-term atmospheric dust loading, and collapse of food systems.
• Supervolcanic eruptions: Rare explosive eruptions (e.g., Yellowstone-scale) could inject large amounts of aerosols into the stratosphere, cooling the planet and damaging agriculture.
• Other cosmic risks: Extremely rare events such as nearby gamma-ray bursts or extreme solar storms could have large effects but are thought to be low probability on human timescales.

Current evidence suggests that, per year, natural existential risks are significantly lower than many anthropogenic ones, though they remain important to monitor and mitigate.

How Likely Are Existential Risks?

Quantifying existential risk is difficult, because there is little historical data and many risks involve unprecedented technologies.

• Deep uncertainty: Expert estimates often rely on structured judgment rather than direct statistical extrapolation.
• Non-additivity: Risks may interact—for example, geopolitical tensions can raise both nuclear and biosecurity risks.
• Subjective estimates: Some scholars argue that total existential risk over the next century is non-trivial (on the order of several percent or higher), though numbers vary widely.

Regardless of the exact figure, the combination of massive stakes and non-negligible probability implies that reducing existential risk is a major global priority from many ethical perspectives.

Strategies to Reduce Existential Risks

Existential risk reduction spans technical, institutional, and cultural interventions. Some approaches address specific threats, while others aim to strengthen our overall resilience and governance capacity.

Targeted Risk Mitigation

• Nuclear risk reduction
  • Arms control, verification, and reduction of stockpiles.
  • Improved command-and-control and crisis communication to reduce accidental or escalatory war.
• Climate and environmental action
  • Rapid decarbonization and adaptation to unavoidable change.
  • Protection of critical ecosystems and biodiversity.
• Biosecurity
  • Stronger laboratory safety and oversight of dual-use research.
  • Global pathogen surveillance, rapid vaccine platforms, and emergency response capacity.
• AI safety and governance
  • Research on alignment, robustness, interpretability, and control of powerful AI systems.
  • National and international frameworks for responsible deployment, auditing, and incident response.

Strengthening Global Resilience

In addition to preventing specific risks, we can make civilization more robust to shocks.

• Resilient infrastructure: Diversified energy, food, and communication systems that can continue operating under stress.
• Redundancy and slack: Strategic reserves of food, medical supplies, and key industrial inputs.
• Emergency governance capacity: Legal and institutional tools for rapid, coordinated response without undermining long-run freedoms.
• Cultures of safety: Norms in science, industry, and government that prioritize risk-awareness and transparent reporting of near misses.

Improving Long-Run Governance and Values

Some of the most important levers are about how we make decisions collectively.

• International cooperation: Mechanisms for states to coordinate on shared threats, share information, and manage arms races.
• Institutional design: Building bodies that can monitor emerging technologies, conduct horizon scanning, and advise policymakers over decades, not just electoral cycles.
• Ethical reflection: Public and expert discourse on what a good long-term future looks like, and how to incorporate the interests of future generations into present decisions.

How Individuals Can Contribute

Even though existential risks operate at a global scale, individuals have meaningful ways to help.

• Career choice: Working directly in biosecurity, AI safety, climate policy, nuclear security, or global governance can have significant impact.
• Research and advocacy: Contributing to academic work, policy analysis, or public communication that improves understanding of x-risks.
• Targeted philanthropy: Supporting organizations that conduct high-quality research or implement interventions to reduce existential risk.
• Civic engagement: Voting, public commenting, and community organizing around responsible technology and global cooperation.

Because these issues are cross-cutting and interdisciplinary, there is room for contributions from diverse backgrounds—science, engineering, law, policy, philosophy, economics, and more.

Frequently Asked Questions (FAQs)

Q1: Are existential risks just science fiction?

No. While some scenarios feature prominently in fiction, the underlying issues—such as nuclear war, climate change, engineered pandemics, and advanced AI—are the subject of serious study by scientists, governments, and international organizations.

Q2: Isn’t focusing on the far future a distraction from current problems?

Not necessarily. Many measures that reduce existential risk—such as strengthening health systems, improving governance, and securing nuclear materials—also benefit people alive today. Moreover, because the future could contain vast numbers of people, safeguarding it can be morally very important.

Q3: Which existential risk is the biggest?

Experts disagree, and precise ranking is difficult. However, advanced artificial intelligence, engineered biological risks, and great-power conflict involving nuclear weapons are often cited as especially concerning this century, while extreme climate or environmental scenarios may amplify these risks or create additional pathways to catastrophe.

Q4: How can anyone estimate the probability of events that have never happened?

Researchers combine theoretical modeling, expert elicitation, near-miss case studies, and analogies to known processes to form structured judgments. These estimates are uncertain and should be continually updated as new evidence appears, but they are still useful for prioritizing action.

Q5: If natural existential risks are small, why worry about them?

Even low annual probabilities accumulate over long timescales, and some mitigation steps—such as asteroid tracking and planetary defense—are relatively inexpensive compared with their potential benefits. At the same time, most researchers prioritize anthropogenic risks, which appear more pressing this century.

Written by

Medha Deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts. Medha specializes in the areas of beauty, health, sports, and wellness and is committed to ensuring that the content on the website is…