Systematic attribution of heatwaves to the emissions of carbon majors – Nature

Report on the Attribution of Extreme Heat Events to Climate Change and Carbon Major Emissions

Executive Summary: Climate Change, Corporate Accountability, and the Sustainable Development Goals

This report details a systematic analysis of 213 historical heatwaves from 2000-2023, establishing a direct causal link between anthropogenic climate change and the increased intensity and frequency of these extreme weather events. Crucially, the analysis extends attribution to 180 major carbon producers (carbon majors), quantifying their specific contributions. These findings provide critical evidence for understanding the profound threats to the United Nations Sustainable Development Goals (SDGs), particularly SDG 13 (Climate Action), SDG 3 (Good Health and Well-being), and SDG 16 (Peace, Justice and Strong Institutions). The research demonstrates that climate change, driven by identifiable actors, has made extreme heatwaves significantly more likely, with emissions from carbon majors contributing to approximately half of the observed increase in heatwave intensity. This establishes a scientific basis for corporate accountability in the context of climate-related damages and strengthens the case for accelerated climate action to protect vulnerable populations and achieve the 2030 Agenda.

1. Systematic Attribution of Heatwaves: A Growing Threat to Global Goals

1.1. Increased Frequency and Intensity

The analysis confirms that human-induced climate change has intensified all 213 heatwaves studied between 2000 and 2023. This trend directly threatens the achievement of multiple SDGs by exacerbating environmental and societal stress.

• Impact on SDG 3 (Good Health and Well-being): Increased heatwave intensity poses severe risks to human health, leading to heat stress, cardiovascular complications, and increased mortality.
• Impact on SDG 11 (Sustainable Cities and Communities): Urban areas are particularly vulnerable to extreme heat, challenging the goal of creating safe and resilient human settlements.
• Impact on SDG 2 (Zero Hunger): Extreme heat can lead to crop failure and water scarcity, undermining food security for vulnerable populations.

The growing influence of climate change is evident in the escalating probability of these events:

1. 2000–2009: The median heatwave became approximately 20 times more likely compared to a preindustrial climate.
2. 2010–2019: The median heatwave became approximately 200 times more likely.
3. Overall Finding: One-quarter of all analyzed heatwave events were determined to be virtually impossible without the influence of anthropogenic climate change.

2. Attribution to Carbon Majors: Quantifying Responsibility for Climate Impacts

2.1. The Causal Chain from Emitters to Events

This report establishes a quantitative causal chain from the emissions of specific corporate and state-owned entities to the increased risk of extreme heat events. This analysis is fundamental to SDG 16 (Peace, Justice and Strong Institutions) by providing an evidentiary basis for accountability and climate litigation.

2.2. Contribution of Major Emitters

The study traces historical emissions from 180 of the largest fossil fuel and cement producers, linking their activities directly to global temperature rise and subsequent climate impacts.

• Share of Emissions: The emissions from these 180 carbon majors represent 57% of total cumulative anthropogenic CO₂ emissions since 1850.
• Contribution to Global Warming: Of the approximate 1.30°C increase in Global Mean Surface Temperature (GMST) by 2023, 0.67°C is directly attributable to the emissions of these carbon majors.
• Impact on Heatwave Intensity: Emissions from carbon majors are responsible for approximately half of the total increase in heatwave intensity observed since the preindustrial era (1850-1900).

2.3. Significance of Individual Contributions

The analysis demonstrates that even smaller carbon majors have a substantial impact on climate stability, reinforcing the principle of shared but differentiated responsibilities required to achieve SDG 13 (Climate Action).

• The emissions of every individual carbon major, from the largest to the smallest, were found to have substantially increased the probability and intensity of all 213 heatwaves.
• Depending on the specific carbon major, its individual emissions were sufficient to enable the occurrence of between 16 and 53 heatwaves that would have been virtually impossible in a preindustrial climate.

3. Discussion and Implications for the 2030 Agenda

3.1. Strengthening Climate Action and Justice

The systematized framework for Extreme Event Attribution (EEA) presented in this report provides robust scientific evidence that can inform policy, support legal action, and drive corporate accountability. This directly supports the implementation of global frameworks for sustainable development.

• SDG 13 (Climate Action): The findings underscore the urgent need for rapid and deep emissions cuts from all sectors, particularly from the major emitters identified.
• SDG 16 (Peace, Justice and Strong Institutions): By filling the “evidentiary gap,” this research provides critical data for climate litigation and strengthens calls for corporations and nations to be held accountable for their contributions to climate change and its associated damages.
• SDG 17 (Partnerships for the Goals): This work highlights the necessity of collaboration between scientists, legal experts, and policymakers to ensure that scientific evidence is effectively integrated into governance and justice systems.

3.2. Limitations and Future Applications

While this assessment is comprehensive, it is limited by incomplete disaster reporting in global databases and the exclusion of certain climate forcers like aerosols. Future work could expand this framework to other climate hazards such as droughts, floods, and sea-level rise, further clarifying their impacts on the full spectrum of Sustainable Development Goals. Extending the analysis to quantify heat-related mortality and economic damages would provide an even clearer picture of the costs of inaction and the responsibilities of major emitters.

1. Which SDGs are addressed or connected to the issues highlighted in the article?

1. SDG 3: Good Health and Well-being

   The article connects to SDG 3 by discussing heatwaves, which are extreme weather events with severe public health consequences. The study analyzes heatwaves reported in the EM-DAT international disaster database, which are included due to “significant economic losses or casualties, a declaration of state of emergency or a call for international assistance.” This directly relates to protecting human health from climate-related risks.

2. SDG 11: Sustainable Cities and Communities

   The article addresses SDG 11 by focusing on the impact of climate-related disasters on human settlements. It analyzes 213 heatwaves across 63 countries, defining the events by their spatial characterization to represent “how the disaster was experienced by the local populations.” This highlights the vulnerability of communities to climate extremes and the need for resilience.

3. SDG 12: Responsible Consumption and Production

   This goal is central to the article’s analysis of “carbon majors,” which it defines as “fossil fuel and cement producers.” By tracing anthropogenic emissions back to these 180 specific corporate entities, the study directly addresses the production patterns that drive climate change and calls for corporate accountability for their environmental impact.

4. SDG 13: Climate Action

   SDG 13 is the primary focus of the article. The entire study is an “extreme event attribution (EEA)” that “assesses how climate change affected climate extremes.” It quantifies the increased intensity and likelihood of heatwaves due to human-induced global warming, providing direct scientific evidence for the urgency of climate action.

5. SDG 16: Peace, Justice and Strong Institutions

   The article explicitly links its findings to SDG 16 by highlighting their relevance for “climate policy, litigation and wider efforts concerning corporate accountability.” It states that the results “contribute to filling the evidentiary gap to establish accountability” and can be used in “climate-related legal proceedings,” thereby strengthening justice and institutional mechanisms for addressing climate change.

2. What specific targets under those SDGs can be identified based on the article’s content?

• SDG 3: Good Health and Well-being

  • Target 3.d: Strengthen the capacity of all countries, in particular developing countries, for early warning, risk reduction and management of national and global health risks. The article’s analysis of heatwave intensity and frequency provides critical information for understanding and managing the growing health risks associated with climate change.

• SDG 11: Sustainable Cities and Communities

  • Target 11.5: By 2030, significantly reduce the number of deaths and the number of people affected and substantially decrease the direct economic losses relative to global gross domestic product caused by disasters… The study is based on heatwaves from the EM-DAT disaster database, which are cataloged precisely because of their significant “casualties” and “economic losses.”

• SDG 12: Responsible Consumption and Production

  • Target 12.6: Encourage companies, especially large and transnational companies, to adopt sustainable practices and to integrate sustainability information into their reporting cycle. The article’s core purpose is to attribute emissions and climate impacts to 180 “carbon majors,” directly encouraging accountability and a shift toward more sustainable practices.

• SDG 13: Climate Action

  • Target 13.1: Strengthen resilience and adaptive capacity to climate-related hazards and natural disasters in all countries. The article quantifies the increasing intensity and likelihood of heatwaves, which are climate-related hazards, providing a scientific basis for strengthening resilience.
  • Target 13.3: Improve education, awareness-raising and human and institutional capacity on climate change mitigation, adaptation, impact reduction and early warning. The study itself is a tool for raising awareness and building institutional capacity, particularly for legal institutions, by providing “evidentiary” support for climate litigation.

• SDG 16: Peace, Justice and Strong Institutions

  • Target 16.3: Promote the rule of law at the national and international levels and ensure equal access to justice for all. The article directly supports this target by stating its results can be used to “fill in evidentiary gaps” in “climate-related legal proceedings,” thereby strengthening the role of law and justice in addressing climate damages.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

• For SDG 13 (Climate Action) and SDG 11 (Sustainable Cities and Communities)

  • Change in heatwave intensity: The article measures the increase in temperature (e.g., “+0.3 °C to +2.9 °C”) for each heatwave compared to a preindustrial climate. This serves as a direct indicator of the worsening impact of climate-related hazards (Target 13.1).
  • Probability Ratio of heatwaves: The study calculates how many times more likely a heatwave has become due to climate change (e.g., “about 20 times more likely over 2000–2009, and about 200 times more likely over 2010–2019”). This measures the increasing risk from climate hazards (Target 13.1).
  • Number of casualties and economic losses from disasters: The article uses the EM-DAT database, which records disasters based on casualties and economic losses, directly aligning with official indicators for Target 11.5 (Indicator 11.5.1 and 11.5.2).

• For SDG 12 (Responsible Consumption and Production)

  • Cumulative CO2 and CH4 emissions from specific producers: The article quantifies the historical emissions traced to 180 “carbon majors.” It states these entities “represent 57% of the total cumulative anthropogenic CO2 emissions.” This data can be used as an indicator to track the production-side responsibility for climate change (Target 12.6).
  • Contribution of carbon majors to global warming: The study calculates the specific contribution of carbon majors to the increase in Global Mean Surface Temperature (GMST), finding that “0.67 °C is due to the emissions of all carbon majors.” This provides a clear metric for corporate impact (Target 12.6).

• For SDG 16 (Peace, Justice and Strong Institutions)

  • Use of scientific evidence in climate litigation: While not a formal metric, the article’s explicit aim to “fill in evidentiary gaps” for “climate litigation” implies that the number of legal cases successfully using such scientific attribution studies could serve as an indicator of progress in ensuring access to climate justice (Target 16.3).

4. Table of SDGs, Targets, and Indicators

Source: nature.com