In recent years, the world has witnessed a staggering increase in the frequency and severity of heatwaves, with these extreme temperature events breaking records across continents and drastically impacting ecosystems, economies, and public health. A groundbreaking study led by Professor Sonia Seneviratne of ETH Zurich offers compelling scientific evidence that human-driven climate change has not only made heatwaves more common but has also significantly amplified their intensity on a global scale between 2000 and 2023. This research, published in the prestigious journal Nature, systematically attributes more than 200 heatwaves worldwide to the carbon emissions of the largest fossil fuel and cement producers, laying bare the substantial role of these “carbon majors” in escalating the heat crisis.
Heatwaves have become a defining feature of the emerging climate landscape, transforming once-rare temperature spikes into near-annual events that challenge infrastructure and threaten lives. From the unprecedented scorching heat waves that gripped Europe in the summer months of recent years to the drought-stricken forests succumbing to wildfires across multiple continents, the evidence increasingly points to a direct linkage between anthropogenic carbon output and these extreme weather phenomena. Unlike previous climate assessments that often focused on emissions at the national level or individual consumption habits, Seneviratne’s team took a novel approach by isolating and quantifying the influence of corporate carbon producers, termed carbon majors, thereby narrowing down accountability to specific industrial actors.
The study meticulously analyzed 213 heatwaves that occurred globally over 23 years, spanning six continents with the notable underrepresentation of Africa and South America due to data scarcity and underreporting challenges. Despite these limitations, the results revealed a troubling trend: the likelihood of heatwaves has increased exponentially due to greenhouse gas emissions. Particularly noteworthy is the finding that between 2000 and 2009, climate change made heatwaves approximately 20 times more likely compared to pre-industrial periods, while between 2010 and 2019, this figure surged to a staggering 200 times more likely, underscoring an accelerating climate crisis linked directly to human activity.
Central to the study’s findings is an unprecedented attribution framework that tracks how the emissions from the 180 largest fossil fuel and cement companies — collectively responsible for about 60% of cumulative anthropogenic CO2 emissions since 1850 — contribute to these extreme heat events. This approach incorporates advanced climate modeling that simulates scenarios both including and excluding emissions from individual carbon majors, thereby isolating their specific imprint on the global temperature rise. This rigorous methodology allows researchers to precisely quantify each company’s role in increasing the probability and severity of heatwaves, providing empirical data essential for both scientific understanding and policy development.
Significantly, the research highlights that responsibility is not evenly distributed among carbon majors. A group of just fourteen companies stands out, collectively contributing as much to global warming as the remaining 166 combined. Among the largest contributors are state-owned and investor-owned fossil fuel giants in the former Soviet Union, alongside China’s coal producers and Middle Eastern oil and gas behemoths like Saudi Aramco, Gazprom, and ExxonMobil. The emissions attributable to these entities alone have induced over 50 heatwaves each, events that would have been virtually impossible without the added warming originating from their operations.
While the dominant role of these major carbon producers is clear, the study also reveals the significant aggregated impact of smaller players within this cohort. Even the emissions from the smallest entity studied, the Russian coal producer Elgaugol, are linked to the increased occurrence of sixteen heatwaves. This nuance emphasizes the pervasive influence of fossil fuel production networks as a whole and challenges narratives that excuse smaller emitters from climate accountability. By revealing how even incremental carbon outputs have cascading effects on climate extremes, the study reinforces the urgency of addressing emissions at all scales.
The implications extend far beyond scientific circles; they touch on the heart of global climate governance and corporate responsibility. Professor Seneviratne and her colleagues underscore that major carbon producers have been cognizant of the environmental risks of fossil fuel combustion since as early as the 1980s. Despite this knowledge, many companies have actively employed disinformation campaigns and robust lobbying efforts to delay meaningful climate action, perpetuating a high-carbon business model at the expense of planetary health. This strategic obstruction has undoubtedly exacerbated the current climate emergency, raising ethical, legal, and political questions about culpability and reparations.
Perhaps most striking is the study’s potential application within the legal domain. By providing a clear scientific basis for linking specific carbon producers to individual heatwave events, the research opens pathways for judicial systems to apply the “polluter pays” principle more decisively in holding corporations accountable for climate damages. Such litigation could redefine responsibility frameworks, forcing emitters to internalize externalities and incentivize accelerated decarbonization efforts. This represents a pivotal shift from collective blame to targeted enforcement, signaling an evolution in climate justice mechanisms around the globe.
Beyond the immediate focus on heatwaves, the ETH Zurich research team envisions expanding this attribution methodology to encompass other extreme weather events such as heavy rainfall, persistent droughts, and wildfires. By systematically mapping the fingerprints of carbon majors across a broader spectrum of disasters, scientists can offer policymakers and the public an increasingly granular understanding of how industrial emissions translate directly into tangible human and environmental harms. This ambition marks a new frontier in climate attribution science, leveraging rigorous data analyses to confront the scale and distribution of climate risks.
The broader climatological community has largely approached attribution studies on an event-by-event basis, limiting the ability to identify overarching patterns or distribute attribution among individual actors. This study’s novelty lies in aggregating multiple events into a coherent analytical framework that quantifies the relative contributions of individual carbon producers over time. The systematic review approach not only establishes stronger causal links but also enriches interdisciplinary discourse by marrying science, policy, and ethics into a unified narrative confronting the climate crisis.
Ultimately, this research contributes to an urgent global conversation about not just how climate change is reshaping the planet, but who carries responsibility for these existential threats. It challenges policymakers, corporate leaders, and society at large to rethink the scale of accountability and the mechanisms by which justice can be served. As global temperatures continue to climb and heatwave events become ever more catastrophic, such scientific examinations will be indispensable for guiding mitigation strategies and shaping equitable climate governance in the coming decades.
The unprecedented heatwaves documented between 2000 and 2023 are more than a symptom of rising temperatures; they are a manifest consequence of decades-long industrial emissions driven by a powerful coalition of carbon majors. With every record shattered and every ecosystem threatened, the world recognizes that solving the climate crisis requires accounting for both systemic contributors and individual culpability. This study’s rigorous attribution of heatwave intensification to carbon majors thus represents not only a scientific milestone but a clarion call for urgent and decisive action against climate change.
Subject of Research: Not applicable
Article Title: Systematic attribution of heatwaves to the emissions of carbon majors
News Publication Date: 10-Sep-2025
Web References: 10.1038/s41586-025-09450-9
References: Research led by ETH Zurich Professor Sonia Seneviratne, published in Nature
Keywords: climate change, heatwaves, carbon majors, fossil fuel emissions, climate attribution, global warming, extreme weather, climate responsibility, ETH Zurich
