Northern peatlands, some of the planet’s most carbon-rich ecosystems, may present a significant and heretofore underappreciated complication to global efforts aimed at controlling climate change, new research suggests. This complexity becomes particularly critical in scenarios where global temperatures temporarily surpass the internationally accepted 1.5°C threshold before retreating. The study, led by the International Institute for Applied Systems Analysis (IIASA) alongside collaborators at East China Normal University, reveals that while these vast wetland regions continue to sequester carbon dioxide (CO₂), they also emit substantial quantities of methane (CH₄), a greenhouse gas with a far stronger warming effect than CO₂ over shorter timescales.
Peatlands, characterized by their waterlogged soils rich in partially decomposed organic matter, cover a surprisingly small fraction of the Earth’s land surface but hold about one-third of the planet’s soil carbon reservoir. Over millennia, low decomposition rates combined with persistent wet conditions have led to the accumulation of thick peat layers, locking carbon away and acting as vital natural sinks. However, these same saturated conditions foster anaerobic microbial processes that generate methane, making peatlands a significant global source of this potent gas.
The research team employed the OSCAR Earth System Model, a cutting-edge computational tool designed to simulate Earth’s carbon and climate dynamics with high fidelity, including complex biogeochemical feedbacks. By integrating detailed peatland processes into the model, the scientists could evaluate how peatland carbon and methane fluxes respond to warming in both steady-state and temperature overshoot trajectories. Their analysis uncovered a pivotal and troubling insight: while warming stimulates greater CO₂ uptake by peatlands, the concurrent increase in methane emissions effectively negates much of this benefit, particularly when temperatures exceed 1.5°C temporarily.
This methane-driven feedback mechanism means that peatlands, often omitted or simplified in climate projections and carbon budgets, may counteract efforts to reduce atmospheric greenhouse gas concentrations more than previously recognized. As temperatures rise, anaerobic peatland microbes become more active, accelerating methane release. Given methane’s heat-trapping capacity—approximately 28–34 times greater than CO₂ over a 100-year period and even more potent on shorter timescales—these emissions substantially undermine the cooling effect of CO₂ sequestration.
The findings sound a cautionary note for climate policymakers who rely on projected carbon removal targets to design mitigation pathways. In scenarios where the Earth’s temperature transiently overshoots 1.5°C before returning to targets, the enhanced methane emissions from northern peatlands introduce a hidden carbon-climate feedback, requiring roughly an additional 10% of carbon removal than current estimates account for. This discrepancy could critically impair international efforts to meet the Paris Agreement goals and maintain global climate stability.
Biqing Zhu, an IIASA researcher and co-lead author of the study, emphasizes that natural ecosystems like peatlands exert complex influences on climate trajectories that are often overlooked in policy and modeling frameworks. “Our results highlight that peatlands, which may seem marginal in their direct effect on peak warming, can substantially complicate cooling efforts after an overshoot event through their methane emissions,” Zhu explains. “This underscores the urgent need to incorporate these feedbacks explicitly into climate strategies to avoid underestimating the scale and cost of achieving net-zero emission targets.”
The study also illustrates the importance of temporal dynamics in Earth system feedbacks. Peatland methane emissions are more sensitive to temperature changes in the near term, which means that even short periods of elevated temperatures can lock-in persistent emissions that resist immediate reversal as temperatures decline. This temporal lag creates a challenge for climate mitigation because warming overshoot—even if temporary—could trigger irreversible feedbacks destabilizing the Earth’s carbon cycle.
Furthermore, the research points out a vexing policy dilemma. While peatlands provide essential ecosystem services beyond carbon storage, including biodiversity support, water regulation, and cultural values, their management must now also consider the amplified methane output under warming scenarios. This complexity demands interdisciplinary collaboration between ecologists, climate scientists, and policymakers to formulate adaptive management plans that balance conservation goals with climate risks.
International cooperation and continued investment in Earth system science are vital, the authors argue, to refine predictive models and reduce uncertainties surrounding peatland carbon-climate feedbacks. Enhanced field observations, remote sensing, and process-based studies will enable better quantification of methane flux sensitivity to warming, hydrological regimes, and land-use perturbations. Such efforts are crucial to developing nuanced climate policies that robustly integrate natural system feedbacks and overshoot risks.
In summary, this new IIASA-led work reveals a formidable challenge: northern peatlands—long heralded as essential carbon sinks—may paradoxically amplify climate risks through increased methane emissions during transient warming overshoot events. This duality, of simultaneous carbon sequestration and methane release, complicates the global carbon budget and heightens the urgency of limiting warming pathways that exceed the 1.5°C guardrail. Accurately incorporating peatland feedbacks could define the difference between feasible climate stabilization and unanticipated warming persistence.
As climate models evolve to embrace these multifaceted Earth system responses, the research community and policymakers face a clear mandate: to anticipate and manage the hidden risks posed by natural systems under climate stress. Peatlands exemplify how intricately interwoven biological processes govern the future trajectory of global warming, requiring an integrated approach that transcends conventional carbon-centric mitigation frameworks and embraces the full spectrum of greenhouse gas dynamics.
Only by acknowledging and addressing these subtle but significant feedbacks can humanity hope to design climate strategies resilient against unexpected reversals. The warming of northern peatlands represents a potent natural amplifier of global temperature overshoot, transforming a temporary breach of climate targets into a prolonged challenge with deep implications for the planet’s future climate stability.
Subject of Research:
Impact of northern peatlands on global climate change, specifically the role of methane emissions in global temperature overshoot scenarios.
Article Title:
Warming of northern peatlands increases the global temperature overshoot challenge.
News Publication Date:
1 July 2025
Web References:
https://doi.org/10.1016/j.oneear.2025.101353
https://iiasa.ac.at/models-tools-data/oscar
References:
Zhu, B., Qiu, C., Gasser, T., Ciais, P., Lamboll, R.D., Ballantyne, A., Chang, J., Chaudhary, N., et al. (2025). Warming of northern peatlands increases the global temperature overshoot challenge. One Earth. DOI: 10.1016/j.oneear.2025.101353
Keywords:
Northern peatlands, methane emissions, carbon sequestration, global warming, temperature overshoot, Earth system feedbacks, climate change mitigation, OSCAR Earth System Model, greenhouse gases, carbon cycle, climate policy, peatland ecosystems
