Climate harm attribution and causation

🔥 𝐓𝐡𝐞 𝐜𝐨𝐮𝐧𝐭𝐫𝐲 𝐦𝐨𝐬𝐭 𝐡𝐨𝐬𝐭𝐢𝐥𝐞 𝐭𝐨 𝐜𝐥𝐢𝐦𝐚𝐭𝐞 𝐩𝐨𝐥𝐢𝐜𝐲 𝐢𝐬 𝐩𝐚𝐲𝐢𝐧𝐠 𝐭𝐡𝐞 𝐡𝐢𝐠𝐡𝐞𝐬𝐭 𝐩𝐫𝐢𝐜𝐞 𝐟𝐨𝐫 𝐜𝐥𝐢𝐦𝐚𝐭𝐞 𝐜𝐡𝐚𝐧𝐠𝐞. A new study in Nature Magazine by researchers at the Stanford Doerr School of Sustainability puts a dollar figure on who is causing climate damage and who is bearing it. The answer, for the United States, is both. 📊 Between 1990 and 2020, US emissions caused $10.2 trillion in global economic damage, making the US the single largest source of climate harm. But the US also suffered $16.2 trillion in losses over the same period, more than any other country. Roughly a third of the damage caused by US emissions, around $3 trillion, fell on the US itself. 🔑 The US economy is so large that even modest percentage reductions in GDP from warming translate into enormous absolute losses. As lead author Marshall Burke puts it: "US emissions have really hurt US output." And the damage extends far beyond American borders: US emissions alone caused $1.4 trillion in losses to the EU, $500 billion to India, and $330 billion to Brazil. 🧩 The finding that should concern policymakers most is the compounding effect. One tonne of CO2 emitted in 1990 caused $180 in global economic damage by 2020. That same tonne will cause an additional $1,840 in damage through 2100. Future damages from past emissions are ten times larger than the damages already incurred. The bill keeps growing, and every year of delay makes it steeper. The researchers frame emissions as unpaid waste disposal. We generate CO2 the way households generate garbage, except we have never paid anyone to deal with it. The bill keeps accruing interest. And these are conservative estimates: the authors exclude biodiversity loss, sea level rise, and several categories of extreme weather events from their calculations. ⚠️ The study also traces damage to corporate emitters. Saudi Aramco's emissions between 1988 and 2015 caused $3 trillion in damages by 2020. If that CO2 stays in the atmosphere through 2100, the projected damage rises to $64 trillion. ExxonMobil's past emissions produced $1.6 trillion in damages by 2020, with $29 trillion more projected through the end of the century. 𝐘𝐨𝐮 𝐜𝐚𝐧 𝐰𝐢𝐭𝐡𝐝𝐫𝐚𝐰 𝐟𝐫𝐨𝐦 𝐚 𝐜𝐥𝐢𝐦𝐚𝐭𝐞 𝐚𝐠𝐫𝐞𝐞𝐦𝐞𝐧𝐭. 𝐘𝐨𝐮 𝐜𝐚𝐧𝐧𝐨𝐭 𝐰𝐢𝐭𝐡𝐝𝐫𝐚𝐰 𝐟𝐫𝐨𝐦 𝐭𝐡𝐞 𝐜𝐨𝐧𝐬𝐞𝐪𝐮𝐞𝐧𝐜𝐞𝐬. Article available here: https://lnkd.in/eEk-ddbN #ClimateChange #Sustainability #ESG #LossAndDamage #CorporateStrategy

For the first time researchers linked the emissions of major carbon emitters to the worsening of 213 heatwaves between 2000-2023. The new article in 'Nature' finds that the emissions of 14 of the largest carbon majors - incl. Exxon, Saudi Aramco, Gazprom - significantly contributed to more than 50 heatwaves that otherwise would have been almost impossible. In other words: about 25% of heatwaves between 2000-23 can be directly linked to the GHG emissions of individual carbon majors (more on the attribution method in the paper). Overall, the emissions from the world’s 180 largest carbon emitters contributed to about half of the increase in intensity of heatwaves. This is an important study, also for legal reasons. With the recent ICJ Advisory Opinion, we are likely to see more climate lawsuits and compensation claims. The findings could provide fresh evidence to support relevant claims. Earlier this year, another paper (again in 'Nature') found that Saudi Aramco and Gazprom alone have each caused a bit more than $2 trillion in heat damage over decades. These studies show: science is turning up the heat on liability... === Article in 'Nature' (Open Access): https://lnkd.in/dewxjnfh Summary: https://lnkd.in/dyizpY9a

With the urgency of halving emissions by 2030, as per the IPCC's recommendation, it is worrying to say the least that corporate responsibility for carbon emissions in 2025 is still marked by a gap between ambitious pledges and actual progress, driven by weak commitments, greenwashing, and inconsistent reporting instead of action. But is that all about to change? A landmark climate case in Germany, in which a Peruvian farmer is suing energy giant RWE for its share of contribution to increased flood risk at his property, is set to be decided later this month. So can climate science attribute economic damage to major polluters? Well possibly yes, thanks to advancements in Attribution Science (altho there are limitations!): The methodology: researchers Justin Mankin (Dartmouth College) and Christopher Callahan (Stanford University) have developed a technique that simulates global average temperatures from 1991 to 2020, with and without emissions from specific fossil fuel companies. They account for both extraction and end-use emissions (e.g., burning fuels by consumers). By mapping global temperature changes to local warming patterns, they focus on the five hottest days annually, which correlate with economic losses from reduced crop yields, increased mortality, and lower labour productivity. Their findings: their analysis attributes $12–49 trillion in global GDP losses over three decades to emissions from major fossil fuel companies, with the top five (Saudi Aramco, Gazprom, Chevron, ExxonMobil, BP) each linked to over $1 trillion in losses. For example, Chevron’s emissions are estimated to have caused $4–61 billion in US GDP losses during a 2012 heatwave. The validation: Experts like Kevin Reed (Stony Brook University) and Friederike Otto (Imperial College London) praise the study as a robust “end-to-end attribution” approach, marking it as a pioneering effort to connect specific emitters to specific damages. Otto suggests that broader adoption by other research groups could refine and strengthen the science. The paper: https://lnkd.in/ezV53Hxa

📢 𝗧𝘄𝗼-𝘁𝗵𝗶𝗿𝗱𝘀 𝗼𝗳 𝗴𝗹𝗼𝗯𝗮𝗹 𝘄𝗮𝗿𝗺𝗶𝗻𝗴 𝗰𝗮𝘂𝘀𝗲𝗱 𝗯𝘆 𝘄𝗼𝗿𝗹𝗱’𝘀 𝗿𝗶𝗰𝗵𝗲𝘀𝘁 𝟭𝟬% Check out our new attribution study in Nature Climate Change led by Sarah Schöngart and co-authored by Zebedee Nicholls, Setu Pelz, Carl-Friedrich Schleussner, and myself. https://lnkd.in/d2Scxtgy 🔎 We link data on emissions #inequality over the period 1990–2020 to regional warming and resulting climate extremes using an emulator-based framework. We find that: ▪️ 𝗧𝘄𝗼-𝘁𝗵𝗶𝗿𝗱𝘀 (𝗼𝗻𝗲-𝗳𝗶𝗳𝘁𝗵) 𝗼𝗳 𝘄𝗮𝗿𝗺𝗶𝗻𝗴 𝗶𝘀 𝗮𝘁𝘁𝗿𝗶𝗯𝘂𝘁𝗮𝗯𝗹𝗲 𝘁𝗼 𝘁𝗵𝗲 𝘄𝗲𝗮𝗹𝘁𝗵𝗶𝗲𝘀𝘁 𝟭𝟬% (𝟭%) of the global population, meaning that their individual contributions are 6.5 (20) times the average per capita contribution to global warming. ▪️For extreme events, the 𝘁𝗼𝗽 𝟭𝟬% (𝟭%) 𝗰𝗼𝗻𝘁𝗿𝗶𝗯𝘂𝘁𝗲𝗱 𝟳 (𝟮𝟲) 𝘁𝗶𝗺𝗲𝘀 𝘁𝗵𝗲 𝗮𝘃𝗲𝗿𝗮𝗴𝗲 𝘁𝗼 𝗶𝗻𝗰𝗿𝗲𝗮𝘀𝗲𝘀 𝗶𝗻 𝗺𝗼𝗻𝘁𝗵𝗹𝘆 𝟭-𝗶𝗻-𝟭𝟬𝟬-𝘆𝗲𝗮𝗿 𝗵𝗲𝗮𝘁 𝗲𝘅𝘁𝗿𝗲𝗺𝗲𝘀 𝗴𝗹𝗼𝗯𝗮𝗹𝗹𝘆 and 6 (17) times more to Amazon droughts. ▪️Our granular impact analysis shows that 𝗹𝗼𝘄-𝗶𝗻𝗰𝗼𝗺𝗲 𝗿𝗲𝗴𝗶𝗼𝗻𝘀 𝗶𝗻𝗰𝘂𝗿 𝘁𝗵𝗲 𝗯𝗿𝘂𝗻𝘁 𝗼𝗳 𝘁𝗵𝗲 𝗵𝗮𝗿𝗺 𝗰𝗮𝘂𝘀𝗲𝗱 𝗯𝘆 𝗲𝗺𝗶𝘀𝘀𝗶𝗼𝗻𝘀 concentrated among wealthier populations worldwide. While emissions inequality has long been recognized, our study is the first to 𝗾𝘂𝗮𝗻𝘁𝗶𝗳𝘆 𝗵𝗼𝘄 𝘁𝗵𝗶𝘀 𝗶𝗻𝗲𝗾𝘂𝗮𝗹𝗶𝘁𝘆 𝘁𝗿𝗮𝗻𝘀𝗹𝗮𝘁𝗲𝘀 𝗶𝗻𝘁𝗼 𝗱𝗶𝘀𝗽𝗿𝗼𝗽𝗼𝗿𝘁𝗶𝗼𝗻𝗮𝘁𝗲 𝗮𝗰𝗰𝗼𝘂𝗻𝘁𝗮𝗯𝗶𝗹𝗶𝘁𝘆 for global temperature rise and extreme climate events. The findings have significant implications for climate justice, underscoring the stark disparities in responsibility for climate impacts. They provide a strong evidence base for 𝗰𝗼𝗺𝗽𝗲𝗻𝘀𝗮𝘁𝗼𝗿𝘆 𝗽𝗼𝗹𝗶𝗰𝘆 𝗺𝗲𝗮𝘀𝘂𝗿𝗲𝘀 𝗮𝗻𝗱 𝗲𝗺𝗶𝘀𝘀𝗶𝗼𝗻 𝗿𝗲𝗱𝘂𝗰𝘁𝗶𝗼𝗻 𝗲𝗳𝗳𝗼𝗿𝘁𝘀 targeting the world’s highest emitters. Nature Magazine, ETH Zürich, International Institute for Applied Systems Analysis (IIASA)

New research quantifies trillions in economic losses directly attributable to emissions from individual fossil fuel companies. After two decades of debate about whether climate litigation could hold emitters accountable, researchers have developed an attribution framework that connects fossil fuel producers to quantifiable economic impacts. By combining emissions data, peer-reviewed attribution methods, and advances in climate economics, scientists can trace the path from corporate emissions to regional economic losses with unprecedented precision. Chevron's emissions alone likely caused between $791 billion and $3.6 trillion in heat-related economic losses between 1991 and 2020. Collectively, emissions from 111 major carbon producers resulted in approximately $28 trillion in global economic damage from extreme heat. These damages disproportionately affect tropical regions that contributed least to emissions, with some areas experiencing GDP per capita reductions exceeding 1%. This end-to-end attribution framework transforms climate litigation by providing courts with scientific evidence meeting "but for" causation standards. While scientific barriers to climate liability have fallen, legal hurdles remain, including questions about which periods should be considered for emissions accounting. The research team advocates for creating a transparent scientific initiative to provide peer-reviewed attributions and expert testimony for courts evaluating climate claims. By Christopher Callahan & Justin Mankin

New climate attribution study out today links carbon emissions from the world's largest fossil fuel and cement producers - the 'carbon majors' - with dangerous and oftentimes deadly heat waves, which are becoming hotter and much more likely to occur as the planet warms. The study, which examined 213 heat waves around the world between 2000 and 2023, found that half of their increase in intensity is attributable to the carbon majors. These firms have also contributed to significant increases in the likelihood of extreme heat events, including some that would have been virtually impossible in a world without climate change. Results also show that even the smaller emitters played a role in the occurrence of some heat waves. The findings could be especially relevant for informing climate accountability initiatives such as litigation. "We can expect this research will be quite relevant in a legal context," Sonia I. Seneviratne, professor at ETH Zurich, told me. Extreme heat is the deadliest type of weather-related hazard. Another new study published Wednesday (by Rupert Stuart-Smith and colleagues) finds that nearly 1,700 heat-related deaths in Zurich, Switzerland, between 1969 and 2018 are attributable to human-induced climate change. The study also estimates that the carbon emissions of the six highest-emitting investor and state-owned companies globally caused, on average, at least one additional death per summer in Zurich since 2004. Researchers say it is clear that fossil fueled-climate change is driving more dangerous and deadly extreme weather impacts and that urgent action is needed to transition away from fossil fuels. "This work is just one more reminder for decisionmakers that we need to phase out fossil fuels as soon as possible," Yann Quilcaille said. https://lnkd.in/emzaMbWQ

I’m really happy to share our recently published paper on detection and attribution of climate change impacts in natural-human systems across the Andes in South America, in Nature Communications Earth & Environment: https://lnkd.in/eJPrNYT8   Our study attributes observed changes in climatic variables, cryosphere, water, hazards, ecosystems, food security, human health, migration, tourism and culture to anthropogenic climate change – to different extents, accounting for multiple drivers of change. It thus provides evidence of observed (mainly negative) substantial impacts of anthropogenic climate change across a ca 8000 km long North-South transect of the Andes region. Particularly noteworthy, and unique for the Andes, is the assessment of cascading impacts from climate to cryosphere to ecosystems and eventually affecting human systems, and their attribution to anthropogenic climate change. My favorite is Figure 4 – have a look at it! We also included local and indigenous knowledge in the analysis. The study contributes to improved evidence of climate change impacts in the region which is essential to take urgently needed action on climate change adaptation and mitigation.   The paper is led by Ana Ochoa Sánchez and a product of the Mentoring and Training Programme in IPCC processes for Early Career Mountain Researchers, supported by the University of Zurich, Mountain Research Initiative (MRI), Helvetas, and ICIMOD, funded by the Swiss Agency for Development and Cooperation (SDC), where we trained a number of great early career researchers from developing countries during the past 6th Assessment Cycle of the IPCC. This was a great experience, and our colleagues are now ready to make a great contribution to the 7th Assessment Cycle of IPCC, by assessing the state of science and building highly needed bridges between science and policy. Ana Elizabeth Ochoa Sánchez, Dáithí Stone, Fabian Drenkhan, Daniel Mendoza, Ronald Gualán Geographisches Institut UZH, University of Zurich, NIWA, Universidad del Azuay

🌊 Environmental Law Enthusiasts 📌 Polluter Pays: Climate Loss & Damage in South Africa Did you know that the April 2022 KwaZulu‑Natal floods—South Africa’s most catastrophic natural disaster in collective terms of lives lost and infrastructure destroyed—have been scientifically linked to climate change, with attribution studies showing the event was twice as likely due to human‑induced greenhouse gas emissions? The Polluter Pays report by the Centre for Environmental Rights is a groundbreaking exploration of how law can be mobilised to hold the world’s largest emitters—the so‑called Carbon Majors—liable for climate‑related loss and damage. It reframes climate disasters not as “acts of God,” but as foreseeable harms rooted in corporate negligence and systemic impunity. ⚖️ Key Legal Insights 1️⃣ Polluter Pays Principle: Rooted in international environmental law, it demands that those responsible for pollution bear the costs of remediation. Applied to climate change, this principle could underpin claims against fossil fuel giants. 2️⃣ Delictual Liability: South African law provides avenues to argue wrongfulness, fault, and causation. Attribution science now strengthens causation arguments by quantifying the extent to which emissions intensified extreme events. 3️⃣ Jurisdiction & Standing: The memorandum explores how South African courts could assert jurisdiction over foreign emitters, and how communities, NGOs, or even municipalities might establish standing to sue. 4️⃣ Parent Company Liability: Multinational structures cannot shield ultimate controllers from accountability. The report highlights how parent companies may be held liable for subsidiaries’ climate harms 📉 Human & Economic Toll 1️⃣ 443 lives lost, 48 missing. 2️⃣ 26,000 dwellings destroyed, 600 schools damaged, 84 health facilities impaired. 3️⃣ Estimated R17 billion in economic losses, excluding unquantified trauma, disrupted education, and social dislocation. 💡 My Takeaway as a Legal Analyst This report is a clarion call for climate litigation in South Africa. It demonstrates how constitutional rights (Section 24: the right to an environment not harmful to health or well‑being) intersect with global climate justice frameworks. It invites us to imagine a jurisprudence where emitters are compelled to finance adaptation, resilience, and reparations for communities most affected. 📣 The Path Forward Climate justice requires moving beyond moral appeals to enforceable legal obligations. The Polluter Pays principle must evolve into actionable claims—transforming climate loss and damage from a humanitarian tragedy into a matter of corporate liability. #ClimateJustice #PolluterPays #SouthAfricanLaw #LossAndDamage #CarbonMajors #EnvironmentalLaw #CER #LegalStrategy #JustTransition #ConstitutionalRights #ClimateLitigation #KZNFloods

State responsibility with respect to climate damage. A lot here! Some points to note: - general customary law rules of state responsibility apply. They are not excluded by the climate treaties. Therefore the responsibility of states for breaches of obligations under the climate treaties is to be determined by applying well established rules of state responsibility under customary international law. - a breach might consist in a failure of a state to take appropriate action to protect the climate system from the effects of GHG emissions including through approval of fossil fuel projects and provision of fossil fuel subsidies - States must exercise regulatory due diligence to regulate the activities of private actors contributing to climate change as a matter of due diligence. This might be breached if the state fails to take necessary regulatory or legislative measures to limit the quantity of GHGs from the activities of private actors like companies which are under the state's jurisdiction or control. - Attribution and causation are more complex in the context of climate change but not impossible to apply. Climate change is caused by cumulative emissions but it is scientifically possible to determine each state's contribution taking into account historical and current emissions. - each state injured by breach of another state(s) international obligations may separately invoke the responsibility of every state that has caused climate harm through its actions or emissions. If several states are responsible, the responsibility of each state may be separately invoked. - Concurrent causes of climate harm are not sufficient to exempt states from the obligation to make reparation in respect of an internationally wrongful act

NEW: Two important attribution studies were published today. I covered both for Carbon Brief. 1️⃣ The first shows that the worlds wealthiest people are the main drivers of worsening climate extremes. It find that the wealthiest 10% are “responsible” for 65% of the 0.61C rise in global average temperatures over 1990-2020. This group contributed 7X more to the rise in monthly heat extremes around the world than the global average. The study also calculates country-level emissions. For example, it finds that emissions from the wealthiest 10% of people in the US alone heat extremes across “vulnerable regions” around the world to double. There are lots of cool details in this study – especially in its methods. Check out my article here: https://lnkd.in/eN2cQwsj 2️⃣ The second study finds that younger generations will face "unprecedented lifetime exposure" to climate extremes. Case study: The authors calculate people living in Brussels in a pre-industrial climate would experience 3 heatwaves in their lives. They would have a 1-in-10,000 chance of experiencing 6 heatwaves. Anything above this is "unprecedented". The authors find that a child born in 2020 in Brussels will experience an unprecedented 11 heatwaves in their lives – even if global warming is limited to 1.5C. Globally, the study finds that over half of children born in 2020 – around 62 million people – will face “unprecedented lifetime exposure” to heatwaves, even if warming is limited to 1.5C. The authors carry out this analysis for five other climate extremes – crop failure, wildfires, droughts, floods and tropical cyclones. Check out these results in the piece: https://lnkd.in/eAzNezRT (There are some great graphics in this piece from the accompanying report by Save the Children too!) 🌍 It was especially cool to see this research come out today, as I spent last week at #EGU25 chatting to attribution experts about how quickly this cutting-edge field is advancing, and how it is already being used in the world of litigation.