A groundbreaking study from the University of Graz has unveiled a highly precise global surface temperature record, providing unprecedented clarity on the urgency and progression of climate change. This new dataset and analytical framework rigorously quantify temperatures up to 2024 and extend projections into the coming decades. Crucially, it offers a refined assessment of whether our collective efforts align with the Paris Agreement’s ambitious targets to keep global warming “well below 2 °C” and ideally within 1.5 °C above pre-industrial levels. The findings suggest that climate thresholds may be reached significantly earlier than previously projected, demanding urgent reevaluation of climate strategies worldwide.
The 2015 Paris Agreement marked a historic international commitment to mitigate the severe consequences of climate change by setting explicit temperature limits. To assess progress, scientists typically track global surface warming averaged over two decades. Prior to this study, the Intergovernmental Panel on Climate Change (IPCC) forecasted crossing the 1.5 °C threshold between 2030 and 2035. However, the University of Graz’s research team, led by climate physicist Gottfried Kirchengast, challenges this timeline. Their meticulously constructed global temperature benchmark now indicates that the critical 1.5 °C increase will be surpassed as early as 2028, with a margin of uncertainty of approximately two years either side.
Central to this research is the development of a new global warming record that integrates a multitude of international datasets and addresses historical uncertainties, particularly concerning surface air temperature over oceans. Traditionally, global warming monitoring over oceans relied on subsurface sea water temperatures, measured by drifting buoys, rather than the air immediately above the surface. This approach created calibration challenges and introduced systematic discrepancies, limiting accuracy. By implementing advanced data harmonization and correction techniques, the Graz team has resolved this long-standing uncertainty, revealing that the actual surface air temperature increase is about six percent greater than conventional records indicated.
The precision of this new global temperature record allows researchers to disentangle human-induced warming influences from natural variability, such as those caused by El Niño events or volcanic eruptions. This ability is transformative for climate science, enabling annually updated predictions of global temperature averages well ahead of time; for instance, the team was able to forecast the 2025 global mean temperature as early as August in the preceding year. Such predictive insight equips policymakers and scientists with actionable intelligence to evaluate how current emission trajectories impact climate goals.
An innovative aspect of the analysis is the proposal of a standardized, four-tier compliance scale to evaluate quantitatively how closely global warming trajectories align with the Paris climate targets. Unlike prior qualitative assessments, this scale offers a clear and objective metric that can be incorporated into political and legal frameworks facilitating transparency and accountability. Kirchengast and his colleagues advocate for this methodology to be institutionalized by authoritative bodies such as the World Meteorological Organization (WMO) and the IPCC, ensuring uniformity in monitoring and reporting among signatory nations.
This elevated clarity also addresses ambiguities inherent in the Paris Agreement’s phrasing, which called for keeping warming “well below 2 °C.” The researchers suggest concretizing this language by defining the upper limit more precisely as “below 1.7 °C,” thereby setting a measurable threshold that can be reliably tracked and enforced. This semantic refinement is vital to clarify international commitments and align them with scientifically robust reference data, making temperature goals verifiable in real time and providing a concrete foundation for accountability.
The dataset, extending back to 1850, is supplemented by model-based projections through 2034 and scenario analyses extending up to 2050. These forecast different pathways: one representing ambitious climate mitigation efforts resulting in net-zero CO₂ emissions around mid-century, and another reflecting continued emission levels with no reductions. The trajectories underscore stark contrasts in global temperature outcomes, vividly illustrating the high stakes of immediate climate action. The model compliant with Paris Agreement goals predicts a significantly moderated warming curve, while the business-as-usual scenario portends a dreaded overshoot exceeding 2 °C, with profound implications for ecosystems and human societies.
By delivering this comprehensive and traceable record, the University of Graz team pioneers a new era in climate monitoring, enhancing the scientific toolkit available for global stakeholders confronting the climate crisis. The open-access availability of these data through the Graz Climate Change Indicators – ClimateTracer portal underscores the commitment to transparency and broad utilization. This resource equips researchers, planners, and policymakers worldwide with authoritative temperature benchmarks vital for evidence-based decision-making.
From a technical standpoint, the research extensively employs advanced statistical methodologies in data reconciliation and filtering to cope with diverse and heterogeneous datasets covering instrumental observations, satellite readings, and climate model outputs. The rigorous calibration against multiple reference points boosts confidence in the results, reduces historical bias effects, and fosters reproducibility. This multidisciplinary approach combining physics, climatology, and data science represents the state-of-the-art in climate metrics development.
The urgency implicit in surpassing the 1.5 °C warming threshold earlier than expected elevates the imperative for enhanced climate policy coordination. The study’s ability to provide near-real-time temperature predictions fosters an adaptive governance regime responsive to evolving climate indicators. It empowers international bodies and national governments with an empirical compass guiding emission reduction policies adjustments, technological deployment, and finance flows targeted at sustainable transition pathways.
In conclusion, this research not only refines our understanding of past and present global warming but fundamentally reshapes the pathway for future climate compliance monitoring. By rooting Paris Agreement goals in a scientifically rigorous and transparent framework, it bridges the gap between political ambition and quantifiable reality. This nexus facilitates informed discourse, strengthens public confidence in climate policies, and galvanizes accelerated actions necessary to avert catastrophic temperature rise. The time for measurable, verifiable, and enforceable climate targets has arguably never been more pressing.
The paper detailing these findings will be published imminently in the journal Communications Earth & Environment, reflecting a milestone in climate change science. The research was conducted under the auspices of the Field of Excellence Climate Change Graz at the University of Graz, with contributions from the Atmospheric Remote Sensing and Climate System Research Group at the Wegener Center. The authors have declared no competing interests, underscoring the objective and transparent nature of their work.
For those interested in exploring the new global temperature dataset or utilizing the ClimateTracer web tools, the University of Graz provides open access portals fostering collaborative and interdisciplinary climate research across the globe. This democratization of data serves as a catalyst for innovation and a shared global accountability mechanism essential for confronting the multifaceted challenges of anthropogenic climate change.
Subject of Research: Not applicable
Article Title: A traceable global warming record and clarity for the 1.5 °C and well-below-2 °C goals.
News Publication Date: 2-Jun-2025
Web References:
- https://www.nature.com/articles/s43247-025-02368-0
- https://climatetracer.earth
- https://climate-change.uni-graz.at/en/
- https://wegcenter.uni-graz.at/en/arsclisys
- https://wegcenter.uni-graz.at/en/
References: DOI: 10.1038/s43247-025-02368-0
Image Credits: © University of Graz – Wegener Center
Keywords: Global warming record, Paris Agreement compliance, surface air temperature, climate projections, traceable benchmark, climate data harmonization, IPCC, climate mitigation scenarios, ClimateTracer, statistical climate analysis, temperature threshold, anthropogenic warming
