The need for such a system has become increasingly urgent. Climate change is not experienced as a single, uniform phenomenon. A warming atmosphere can intensify heat stress, alter rainfall, increase the likelihood of drought, raise wildfire danger, reduce snow cover, amplify coastal flooding and influence ocean conditions. Each of these physical changes can affect people, ecosystems, infrastructure and economies in different ways. Yet scientific assessments, impact databases and adaptation plans frequently categorize these events according to separate traditions. One study may focus on temperature extremes, another on crop losses, and a third on health outcomes, without providing a consistent method for linking them.

The new taxonomy is rooted in concepts developed by the Intergovernmental Panel on Climate Change, particularly the idea of “climatic impact-drivers.” These are physical climate conditions that can influence natural or human systems. They include variables such as mean temperature, extreme heat, precipitation, wind, humidity, ocean chemistry, sea level and the duration or timing of climate events. The crucial point is that a climatic impact-driver is not automatically an impact or even a hazard. Its consequences depend on where it occurs, how intense or persistent it is, what is exposed to it and how vulnerable that exposed system may be.

That distinction gives the framework its technical power. A physical driver, such as unusually high temperature, can become a hazard when it reaches a level capable of causing harm. The hazard may then interact with exposure—for example, people living in a dense urban area or crops growing during a sensitive stage of development. Vulnerability, determined by factors such as age, health, income, infrastructure quality, ecological condition or adaptive capacity, shapes the eventual risk. In this structure, risk is not simply “the climate event.” It emerges from the interaction between the physical event and the characteristics of the system in its path.

The authors’ taxonomy operationalizes these relationships by providing a structured way to describe climate impacts across multiple levels. Instead of treating an impact as an isolated label, the system can represent the chain connecting a changing physical condition to a specific consequence. A heatwave, for instance, may be recorded not only as an extreme temperature event but also according to its duration, timing, geographic extent and intensity. The framework can then connect that event to heat-related illness, reduced labor productivity, crop damage, electricity demand or ecosystem stress, while distinguishing among the different pathways that produce each outcome.

This kind of organization could transform the way evidence from different fields is combined. Climate modelers often work with physical indicators, such as the number of days above a temperature threshold or the frequency of intense rainfall. Public-health researchers may track hospital admissions, mortality or disease transmission. Agricultural scientists measure yield losses, soil moisture and crop development. Engineers evaluate infrastructure failure, while ecologists monitor species distribution and ecosystem function. A shared taxonomy can act as a translation layer among these disciplines, helping researchers determine whether apparently different studies are examining related drivers, comparable hazards or entirely different parts of the climate-risk chain.

The framework may also help prevent a common error in climate communication: presenting every damaging event as a direct and interchangeable consequence of global warming. Attribution requires precision. Climate change may increase the probability or severity of a heatwave, but the number of people harmed can depend on housing, healthcare access, working conditions, urban design and public warnings. Similarly, heavier rainfall can raise flood risk, while the actual damage depends on drainage systems, land use, river management and the location of buildings. By separating drivers from exposure, vulnerability and impacts, the taxonomy makes those causal links visible rather than collapsing them into a single headline.

For decision-makers, that clarity could be especially valuable. Adaptation measures are most effective when they target the mechanism creating the risk. Early-warning systems, cooling centers and changes to labor schedules may reduce the health consequences of extreme heat. Improved drainage, flood barriers and restrictions on development in high-risk zones may address intense precipitation and flooding. Drought-resistant crops, water conservation and irrigation management may reduce agricultural vulnerability. A taxonomy that identifies the relevant driver and impact pathway can help governments and organizations match interventions to specific risks instead of relying on broad, nonspecific climate categories.

The researchers also present the taxonomy as a foundation for more consistent data systems. Climate impacts are increasingly recorded in scientific assessments, insurance models, disaster databases, corporate disclosures and national adaptation plans. If these resources classify events differently, important patterns can remain hidden. Standardized terminology could improve the interoperability of datasets, allowing analysts to compare impacts across regions and sectors while retaining information about local conditions. It could also support automated tools that search large scientific databases, identify emerging risks and connect physical climate projections with evidence about health, infrastructure, food systems and ecosystems.

The taxonomy does not eliminate uncertainty, and it cannot predict every future consequence of climate change. Climate risks are dynamic: exposure changes as cities grow, populations move, economies develop and ecosystems respond. Vulnerability can decrease through investment and preparedness, or increase through inequality, environmental degradation and institutional failure. Physical drivers can also interact, producing compound events such as heat combined with drought, extreme rainfall following wildfire or coastal flooding occurring alongside heavy river discharge. The value of the proposed system is that it offers a disciplined way to describe these complexities. As climate impacts accelerate and decisions become more urgent, a shared scientific language may prove almost as important as the projections themselves.

Subject of Research: Climate impact taxonomy linking IPCC physical climate drivers, hazards, exposure, vulnerability and risks.

Article Title: A climate impact taxonomy operationalizing IPCC physical driver and risk concepts

Article References: Werning, M., Byers, E., Andrijevic, M. et al. A climate impact taxonomy operationalizing IPCC physical driver and risk concepts. Nature Climate Change (2026). https://doi.org/10.1038/s41558-026-02717-7

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41558-026-02717-7

Keywords: climate change, climate impacts, climate risk, climatic impact-drivers, IPCC, hazards, exposure, vulnerability, adaptation, taxonomy, climate assessment, extreme weather

The research, published in Nature Climate Change, addresses a long-standing challenge in climate communication. IPCC assessment reports contain an enormous body of evidence on climate processes, impacts, vulnerability, adaptation, and mitigation, but these areas are often presented in separate sections and at different levels of analysis. A policymaker assessing flood protection, for example, may need to navigate information about extreme precipitation, sea-level rise, exposure, infrastructure vulnerability, urban development, and adaptation limits across multiple chapters and reports. The new taxonomy offers a common structure for bringing those elements together, creating a direct pathway from a changing climate variable to a specific risk and then to possible responses.

At the center of the framework are the 35 climatic impact-drivers identified by the IPCC. These drivers describe physical changes in the climate system that can affect natural and human systems. They include gradual trends, such as increasing average temperatures, ocean warming, sea-level rise, and changes in precipitation, as well as extreme events, including heatwaves, intense rainfall, floods, droughts, wildfires, and tropical cyclones. By organizing these drivers systematically, the taxonomy helps users distinguish between the underlying climate signal and the consequences that emerge when that signal interacts with ecosystems, infrastructure, economies, and communities.

The taxonomy then links the climatic impact-drivers to eight representative key risks recognized in IPCC science. These risks encompass threats to ecosystems, human health and wellbeing, food and water security, infrastructure and critical services, cities and settlements, and other systems essential to society. The connections are not simply a list of hazards. Each one reflects a chain of cause and effect: a physical climate change can alter environmental conditions, those changes can affect an exposed system, and vulnerability can determine whether the result becomes a serious risk. The framework therefore provides a way to understand why the same hazard can produce very different outcomes in different places.

Each driver-risk connection is supplemented with information intended for practical use. The entries identify the scale at which impacts are likely to occur, the sectors or systems affected, examples of adaptation responses, and relevant links to mitigation. They also point users toward the IPCC chapters where the underlying scientific evidence is discussed. This design allows the taxonomy to function as both a navigation system and a knowledge map. A user interested in extreme heat and human health, for instance, could identify the relevant risk, examine the populations and systems most exposed, review adaptation options such as heat-health warning systems or urban cooling measures, and trace the information back to the scientific literature.

“This work is less about producing new climate science and more about making existing information actionable,” says lead author Michaela Werning, a researcher in the IIASA Energy, Climate, and Environment Program. She explains that the complexity and scope of IPCC reports can make them difficult to navigate, particularly for users who need to make decisions rather than conduct a comprehensive scientific review. By directly linking measurable climatic impact-drivers with risks and possible responses, the taxonomy is intended to provide a more accessible entry point without separating practical guidance from the scientific assessments on which it is based.

The analysis reveals several important patterns in the global landscape of climate risk. More than half of the hazard-risk combinations compiled by the researchers primarily unfold at regional scales. This finding highlights why climate impacts cannot be understood solely through global averages. Regional geography, infrastructure, ecosystems, socioeconomic conditions, and patterns of exposure can strongly influence the consequences of a given climatic change. A heatwave may intensify health risks in a densely populated city with limited green space, while drought may threaten food production in one region and hydropower generation in another. The regional emphasis also reinforces the need for adaptation strategies tailored to local conditions rather than copied uniformly across countries.

The taxonomy further shows an almost even division between gradual climate changes and extreme events. This balance challenges the tendency to associate climate adaptation mainly with disasters that arrive suddenly and visibly. Extreme heat, floods, storms, and fires require emergency preparedness and rapid response, but long-term changes in temperature, precipitation, sea level, and ecosystem conditions can quietly reshape risks over decades. Communities must therefore invest in both immediate resilience and long-range planning. Building codes, water management systems, agricultural practices, land-use decisions, health services, and infrastructure investments may need to account for climate conditions that are steadily moving beyond the range experienced in the past.

The timing of risk escalation provides another warning. Just under half of the driver-risk combinations assessed in the taxonomy are expected to reach high levels of risk at approximately 1.5°C of global warming, while a similar share reaches high risk only beyond 2°C. These thresholds are not universal tipping points; risk develops along different pathways depending on the hazard, location, exposure, vulnerability, and capacity to adapt. Nevertheless, the pattern demonstrates why mitigation and adaptation cannot be treated as alternatives. Rapid reductions in greenhouse gas emissions can limit the magnitude of future climate change, while adaptation can reduce the damage associated with impacts that are already unavoidable or worsening. The framework also identifies areas where evidence remains limited, helping researchers prioritize future studies and improve the reliability of climate-risk assessments.

The authors envision the taxonomy being used by climate service providers, adaptation planners, policymakers, and scientists. It could support customized risk dashboards, help planners compare response options, and clarify how emission reductions influence future risks across sectors. Its developers stress that the current version is a prototype and that its value will depend on continued testing, feedback, and refinement by both researchers and practitioners. “No single team has the expertise to cover the full breadth of climate impacts on its own,” says coauthor Alexander Nauels, a senior research scholar in IIASA’s Integrated Climate Impacts Research Group. The team is inviting users to challenge and improve the framework so that it can evolve into a shared language for climate action. As climate impacts become more frequent and decisions must be made under increasing uncertainty, that common language could help close one of the most important gaps in climate science: the distance between knowing what is happening and knowing what to do next.

Subject of Research: A climate impact taxonomy linking IPCC climatic impact-drivers, representative key risks, adaptation options, mitigation links, affected systems, and relevant scientific evidence.

Article Title: A climate impact taxonomy operationalizing IPCC physical driver and risk concepts

Web References: https://www.nature.com/articles/s41558-026-02717-7; https://www.iiasa.ac.at

References: Werning, M., Byers, E., Andrijevic, M., Schleussner, C.-F., Monteith, S., Aldrete Lopez, L., Lemaire, V., Matsumae, E., Thomas, A., and Nauels, A. (2026). “A climate impact taxonomy operationalizing IPCC physical driver and risk concepts.” Nature Climate Change. DOI: 10.1038/S41558-026-02717-7

Keywords: climate change, climate impacts, climate risks, adaptation, mitigation, IPCC, climatic impact-drivers, extreme heat, floods, drought, wildfire, sea-level rise, climate science, climate policy, resilience, climate services