Is climate change an existential crisis caused by human activities
Executive summary
Scientific and policy reports in 2025 describe human-caused greenhouse gas (GHG) emissions as the primary driver of recent warming and warn of accelerating harms to health, ecosystems and economies; major assessments say impacts are already widespread and risks rise with each fraction of a degree [1] [2] [3]. Some commentators and institutions frame the situation as approaching existential thresholds—for example, risks of tipping points beyond 1.5°C and a “hothouse Earth” pathway—while at least one U.S. government report questions the scale and immediacy of national policy impacts on the global climate [4] [5] [6].
1. Human activity is identified as the main cause of recent warming
Leading scientific summaries in 2025 continue to attribute current climate change largely to human-driven alterations of the climate system—especially rising GHG concentrations and ocean heat content—which have reached record or near-record levels and are linked to more frequent extreme weather, sea-level rise and retreating ice [2] [1]. Reports cited in 2025 explicitly state that the “consequences of human-driven alterations of the climate are no longer future threats but are here now” [1].
2. How serious: near-term harms to people, health and livelihoods
Health-focused assessments describe concrete, near-term harms: the Lancet Countdown and WHO partners report worsening health indicators, with millions of lives affected through heat exposure, food insecurity and disease risks; the Lancet finds multiple health indicators at record levels and ties many impacts directly to fossil-fuel-driven emissions [3] [7] [8]. The UN and allied analyses similarly warn that unchecked warming will undermine development, intensify resource conflicts and displace people [9] [2].
3. Existential framing and tipping-point risks
Some scientific commentary and syntheses frame climate change as an existential or near-existential risk because of the possibility of large Earth-system “tipping points”—for example, risks to the Amazon or major ice sheets—that could trigger self-reinforcing warming and very large, hard-to-reverse changes [4] [5]. These sources argue that exceeding 1.5°C raises both immediate harms and the odds of crossing thresholds that would dramatically amplify impacts, potentially locking in outcomes far more severe than incremental warming [4] [5].
4. Quantifying the trajectory: where models and pledges leave us
Analyses of national pledges and policy implementation in 2025 show the world remains on track for substantial warming: UNEP’s Emissions Gap work projects around 2.3–2.8°C depending on implementation, and analysts warn that every fraction of a degree avoided reduces risks and dependence on uncertain removal technologies [10]. The World Resources Institute and other trackers say current action falls short of keeping the Paris goals within reach and that remaining carbon stocks—especially in forests—are vulnerable [11].
5. Disagreement within policy and government circles
Not all official voices adopt the same existential framing. A Department of Energy report released in 2025 characterizes climate change as real but argues U.S. policy alone will have only small, delayed detectable effects on the global climate and questions claims that climate is the “greatest threat” to humanity [6]. This highlights an explicit policy disagreement: many global scientific and health organizations emphasize urgent global mitigation and adaptation, while some national reports stress trade-offs and limited national leverage [3] [6].
6. What “existential” means—and why definitions matter
The term “existential” is used in media and expert commentary to denote very different thresholds—from severe, widespread suffering and systemic collapse in regions to global civilization-scale collapse. The 2025 literature links existential concerns primarily to the risk of irreversible Earth-system feedbacks and very high-end warming scenarios (e.g., “hothouse Earth”), not to immediate total annihilation of humanity; sources stress growing, potentially irreversible harms even well below the most extreme scenarios [4] [5] [1].
7. Policy implications and contested priorities
Most health, scientific and UN-linked sources call for rapid mitigation, adaptation finance and protection of vulnerable populations to reduce mortality and systemic risk [7] [2] [3]. Conversely, critiques emphasizing different policy priorities argue for balancing energy access and economic concerns, warning against overstating national impacts of unilateral action [6]. Readers should note these competing agendas: climate scientists and health organizations press urgency to avoid high-end risks, while some policy analyses foreground economic development and national-scale cost-benefit calculations [3] [6].
8. Bottom line and limits of available reporting
Available 2025 reporting consistently identifies human greenhouse-gas emissions as the principal driver of recent warming and documents substantial, increasing harms to health, ecosystems and economies [1] [2] [3]. Some expert voices elevate the language to “existential” because of tipping-point risks and potential runaway feedbacks, while at least one government report disputes the immediacy or magnitude of national policy effects—an explicit policy disagreement in the record [4] [6]. Available sources do not mention a single, universally agreed definition of “existential” in this context; readers should therefore weigh both the scientifically documented, present harms and the contested judgments about long‑term, global-level catastrophe [1] [3] [4].