🌍⚖️ Sébastien Duyck
@duycks.bsky.social
Senior Attorney - #ClimateJustice & right to healthy environment at
the Center for International Environmental Law @ciel.org | demystifying international law, one emoji at a time | Focused on #ClimateJusticeAtTheICJ | Dad * Opinions my own
the Center for International Environmental Law @ciel.org | demystifying international law, one emoji at a time | Focused on #ClimateJusticeAtTheICJ | Dad * Opinions my own
40/ And it's a wrap.
The plaintiffs are now exiting the courthouse. Stay tuned for additional information on the case and the decision of the judges in this #ClimateLitigation case.
🌅Let the era of impunity come to an end and rule of law be upheld.
The plaintiffs are now exiting the courthouse. Stay tuned for additional information on the case and the decision of the judges in this #ClimateLitigation case.
🌅Let the era of impunity come to an end and rule of law be upheld.
September 3, 2025 at 9:58 AM
40/ And it's a wrap.
The plaintiffs are now exiting the courthouse. Stay tuned for additional information on the case and the decision of the judges in this #ClimateLitigation case.
🌅Let the era of impunity come to an end and rule of law be upheld.
The plaintiffs are now exiting the courthouse. Stay tuned for additional information on the case and the decision of the judges in this #ClimateLitigation case.
🌅Let the era of impunity come to an end and rule of law be upheld.
33/ 🐾 Alpine Groundhogs are true hibernators, sleeping deeply for approximately 200 days each year.
🐾 They use loud, shrill whistles to alert their colony to the presence of predators.
🐾 Their large incisors grow continuously, allowing them to process their diet.
📸 Photo credit: Estebandh
🐾 They use loud, shrill whistles to alert their colony to the presence of predators.
🐾 Their large incisors grow continuously, allowing them to process their diet.
📸 Photo credit: Estebandh
September 3, 2025 at 9:24 AM
33/ 🐾 Alpine Groundhogs are true hibernators, sleeping deeply for approximately 200 days each year.
🐾 They use loud, shrill whistles to alert their colony to the presence of predators.
🐾 Their large incisors grow continuously, allowing them to process their diet.
📸 Photo credit: Estebandh
🐾 They use loud, shrill whistles to alert their colony to the presence of predators.
🐾 Their large incisors grow continuously, allowing them to process their diet.
📸 Photo credit: Estebandh
32/ Rather than to summarise the ongoing litany of appalling arguments and to preserve your (and my) sanity, let us turn our attention to fascinating facts concerning Alpine Groundhogs, one of the national symbols of Switzerland...
📸 Photo credit: Niklas Jeromin
📸 Photo credit: Niklas Jeromin
September 3, 2025 at 9:24 AM
32/ Rather than to summarise the ongoing litany of appalling arguments and to preserve your (and my) sanity, let us turn our attention to fascinating facts concerning Alpine Groundhogs, one of the national symbols of Switzerland...
📸 Photo credit: Niklas Jeromin
📸 Photo credit: Niklas Jeromin
22/ In today's hearing, replace "energy" with "cement" and you would have a good overview of the flawed playbook used by Holcim's legal team to demand impunity for their client.
September 3, 2025 at 8:28 AM
22/ In today's hearing, replace "energy" with "cement" and you would have a good overview of the flawed playbook used by Holcim's legal team to demand impunity for their client.
21/ ⚖️ 🇩🇪 The 𝑆𝑎ú𝑙 𝐿𝑢𝑐𝑖𝑎𝑛𝑜 𝐿𝑙𝑖𝑢𝑦𝑎 𝑣. 𝑅𝑊𝐸 judgement is highly relevant as German utility company RWE used a very similar defence which was finally rejected point by point by the German judges as a result of a 10-year long judicial process.
🔍 Here are some highlights from this recent decision ⬇️
🔍 Here are some highlights from this recent decision ⬇️
September 3, 2025 at 8:22 AM
21/ ⚖️ 🇩🇪 The 𝑆𝑎ú𝑙 𝐿𝑢𝑐𝑖𝑎𝑛𝑜 𝐿𝑙𝑖𝑢𝑦𝑎 𝑣. 𝑅𝑊𝐸 judgement is highly relevant as German utility company RWE used a very similar defence which was finally rejected point by point by the German judges as a result of a 10-year long judicial process.
🔍 Here are some highlights from this recent decision ⬇️
🔍 Here are some highlights from this recent decision ⬇️
16/ ⚖️ In its 2024 seminal decision 𝐾𝑙𝑖𝑚𝑎𝑠𝑒𝑛𝑖𝑜𝑟𝑖𝑛𝑛𝑒𝑛 𝑣. 𝑆𝑤𝑖𝑡𝑧𝑒𝑟𝑙𝑎𝑛𝑑 🇨🇭, the European Court of Human Rights stressed the importance of domestic courts in climate-related litigation and the importance of access to justice.
September 3, 2025 at 7:53 AM
16/ ⚖️ In its 2024 seminal decision 𝐾𝑙𝑖𝑚𝑎𝑠𝑒𝑛𝑖𝑜𝑟𝑖𝑛𝑛𝑒𝑛 𝑣. 𝑆𝑤𝑖𝑡𝑧𝑒𝑟𝑙𝑎𝑛𝑑 🇨🇭, the European Court of Human Rights stressed the importance of domestic courts in climate-related litigation and the importance of access to justice.
14/ 👨⚖️ 🎉 In October 2023, a different judge from the same tribunal granted legal assistance to the plaintiffs, recognizing that their legal arguments were not devoid of any chances of success & rejecting the arguments of Holcim's legal team.
September 3, 2025 at 7:45 AM
14/ 👨⚖️ 🎉 In October 2023, a different judge from the same tribunal granted legal assistance to the plaintiffs, recognizing that their legal arguments were not devoid of any chances of success & rejecting the arguments of Holcim's legal team.
11/🧑⚖️📑 Article 49 of the Swiss Code of Obligations complements this legal basis, stressing that those whose personality rights have been infringed can claim compensation (incl. through financial compensation).
September 3, 2025 at 7:35 AM
11/🧑⚖️📑 Article 49 of the Swiss Code of Obligations complements this legal basis, stressing that those whose personality rights have been infringed can claim compensation (incl. through financial compensation).
10/ 🧑⚖️📑 The legal basis is Article 28 of the Swiss Civil Code, protecting the personality rights of individuals from infringements by other persons or entities and providing a right to remedy.
What the plaintiffs seek: the application -in the context of climate harms- of this fundamental principle.
What the plaintiffs seek: the application -in the context of climate harms- of this fundamental principle.
September 3, 2025 at 7:29 AM
10/ 🧑⚖️📑 The legal basis is Article 28 of the Swiss Civil Code, protecting the personality rights of individuals from infringements by other persons or entities and providing a right to remedy.
What the plaintiffs seek: the application -in the context of climate harms- of this fundamental principle.
What the plaintiffs seek: the application -in the context of climate harms- of this fundamental principle.
9/📌 What is specific to this case (compared to human rights-based climate litigation for instance) is its horizontal nature, typical to civil law claims: individual plaintiffs are seeking redress from another private person who contributed to the harm they suffered.
September 3, 2025 at 7:25 AM
9/📌 What is specific to this case (compared to human rights-based climate litigation for instance) is its horizontal nature, typical to civil law claims: individual plaintiffs are seeking redress from another private person who contributed to the harm they suffered.
5/ 🏭 The defendant: Holcim, one of world's largest climate polluters.
According to the Climate Accountability Institute, Holcim is responsible for 0.42% of global industrial CO2 since 1750 - more than twice Switzerland's footprint.
More information: callforclimatejustice.org/wp-content/u...
According to the Climate Accountability Institute, Holcim is responsible for 0.42% of global industrial CO2 since 1750 - more than twice Switzerland's footprint.
More information: callforclimatejustice.org/wp-content/u...
September 3, 2025 at 7:04 AM
5/ 🏭 The defendant: Holcim, one of world's largest climate polluters.
According to the Climate Accountability Institute, Holcim is responsible for 0.42% of global industrial CO2 since 1750 - more than twice Switzerland's footprint.
More information: callforclimatejustice.org/wp-content/u...
According to the Climate Accountability Institute, Holcim is responsible for 0.42% of global industrial CO2 since 1750 - more than twice Switzerland's footprint.
More information: callforclimatejustice.org/wp-content/u...
4/ ✊ The plaintiffs are islanders from the Pari Island, Indonesia 🇮🇩: Arif Pujianto, Ibu Asmania, Pak Bobby & Edi Mulyono.
Their island & means of subsistence face existential threat - but mitigation & adaptation measures cld prevent further harms.
Read more: callforclimatejustice.org/en/plaintiffs/
Their island & means of subsistence face existential threat - but mitigation & adaptation measures cld prevent further harms.
Read more: callforclimatejustice.org/en/plaintiffs/
September 3, 2025 at 6:56 AM
4/ ✊ The plaintiffs are islanders from the Pari Island, Indonesia 🇮🇩: Arif Pujianto, Ibu Asmania, Pak Bobby & Edi Mulyono.
Their island & means of subsistence face existential threat - but mitigation & adaptation measures cld prevent further harms.
Read more: callforclimatejustice.org/en/plaintiffs/
Their island & means of subsistence face existential threat - but mitigation & adaptation measures cld prevent further harms.
Read more: callforclimatejustice.org/en/plaintiffs/
⚡ ⚖️ 🌐 happening now: #ClimateLitigation court hearing in Zug, Switzerland 🇨🇭, in 𝐴𝑠𝑚𝑎𝑛𝑖𝑎 𝑣. 𝐻𝑜𝑙𝑐𝑖𝑚.
This civil law case seeks to hold one of the largest carbon major accountable for climate harms.
🧵 live reporting from the Court house, with summary of legal arguments and key elements of context👇
This civil law case seeks to hold one of the largest carbon major accountable for climate harms.
🧵 live reporting from the Court house, with summary of legal arguments and key elements of context👇
September 3, 2025 at 6:35 AM
⚡ ⚖️ 🌐 happening now: #ClimateLitigation court hearing in Zug, Switzerland 🇨🇭, in 𝐴𝑠𝑚𝑎𝑛𝑖𝑎 𝑣. 𝐻𝑜𝑙𝑐𝑖𝑚.
This civil law case seeks to hold one of the largest carbon major accountable for climate harms.
🧵 live reporting from the Court house, with summary of legal arguments and key elements of context👇
This civil law case seeks to hold one of the largest carbon major accountable for climate harms.
🧵 live reporting from the Court house, with summary of legal arguments and key elements of context👇
4/ 🏝️ Without urgent action, much of Pari Island could be underwater by 2050. Rising seas, worsening disasters, and dying coral reefs are already threatening livelihoods and casting a shadow over the future prospects of the Pari Islanders.
September 2, 2025 at 12:52 PM
4/ 🏝️ Without urgent action, much of Pari Island could be underwater by 2050. Rising seas, worsening disasters, and dying coral reefs are already threatening livelihoods and casting a shadow over the future prospects of the Pari Islanders.
⚡ ⚖️ 🌐 upcoming #𝐂𝐥𝐢𝐦𝐚𝐭𝐞𝐋𝐢𝐭𝐢𝐠𝐚𝐭𝐢𝐨𝐧: Asmania v. Holcim
Crucial hearing upcoming in Switzerland, this could set a precedent for holding climate polluters accountable.
📅 Wed, 3 Sept 2025 – starting at 8:30 am CEST
📍 Cantonal Parliament of Zug🇨🇭
👇 A brief thread🧵
Crucial hearing upcoming in Switzerland, this could set a precedent for holding climate polluters accountable.
📅 Wed, 3 Sept 2025 – starting at 8:30 am CEST
📍 Cantonal Parliament of Zug🇨🇭
👇 A brief thread🧵
September 2, 2025 at 12:52 PM
⚡ ⚖️ 🌐 upcoming #𝐂𝐥𝐢𝐦𝐚𝐭𝐞𝐋𝐢𝐭𝐢𝐠𝐚𝐭𝐢𝐨𝐧: Asmania v. Holcim
Crucial hearing upcoming in Switzerland, this could set a precedent for holding climate polluters accountable.
📅 Wed, 3 Sept 2025 – starting at 8:30 am CEST
📍 Cantonal Parliament of Zug🇨🇭
👇 A brief thread🧵
Crucial hearing upcoming in Switzerland, this could set a precedent for holding climate polluters accountable.
📅 Wed, 3 Sept 2025 – starting at 8:30 am CEST
📍 Cantonal Parliament of Zug🇨🇭
👇 A brief thread🧵
67/ 🔜Please do not miss our high-level panel tomorrow to unpack key learnings from this historic judicial ruling and what lays ahead!
📅July 24., 5:30pm CEST
📝online registration: bit.ly/ICJresponse
#AOLetsGo #ClimateJusticeAO
📅July 24., 5:30pm CEST
📝online registration: bit.ly/ICJresponse
#AOLetsGo #ClimateJusticeAO
July 23, 2025 at 4:08 PM
67/ 🔜Please do not miss our high-level panel tomorrow to unpack key learnings from this historic judicial ruling and what lays ahead!
📅July 24., 5:30pm CEST
📝online registration: bit.ly/ICJresponse
#AOLetsGo #ClimateJusticeAO
📅July 24., 5:30pm CEST
📝online registration: bit.ly/ICJresponse
#AOLetsGo #ClimateJusticeAO
65/ The registrar now reads the conclusions in French... Note that all of the Court's conclusions were unanimous, providing the maximum weight to these legal conclusions.
July 23, 2025 at 4:06 PM
65/ The registrar now reads the conclusions in French... Note that all of the Court's conclusions were unanimous, providing the maximum weight to these legal conclusions.
31/ The Court take a no-nonsense approach to reading the key elements of Article 4 of the Paris Agreement, which explicitly requires:
📈progression over time
💪highest possible ambition
🌡️adequate contribution to the achievement of the temperature goal at the light of equity
📈progression over time
💪highest possible ambition
🌡️adequate contribution to the achievement of the temperature goal at the light of equity
July 23, 2025 at 2:04 PM
31/ The Court take a no-nonsense approach to reading the key elements of Article 4 of the Paris Agreement, which explicitly requires:
📈progression over time
💪highest possible ambition
🌡️adequate contribution to the achievement of the temperature goal at the light of equity
📈progression over time
💪highest possible ambition
🌡️adequate contribution to the achievement of the temperature goal at the light of equity
28/🪧✊Ten yrs ago in negotiations leading to the Paris Agreement, vulnerable States & civil society mobilized to secure a reference to the 1.5c temperate limit in the agreement, building on the IPCC findings. 👉The Court made clear today that this is now the only relevant limit.
July 23, 2025 at 1:55 PM
28/🪧✊Ten yrs ago in negotiations leading to the Paris Agreement, vulnerable States & civil society mobilized to secure a reference to the 1.5c temperate limit in the agreement, building on the IPCC findings. 👉The Court made clear today that this is now the only relevant limit.
25/ Through this clear statement, the Court puts to rest - hopefully once and for all - the bad faith legal argument used by polluters to claim that the climate agreements protect them from accountability for climate harms.
🪦R.I.P. Lex Specialis argument in climate justice cases
🪦R.I.P. Lex Specialis argument in climate justice cases
July 23, 2025 at 1:52 PM
25/ Through this clear statement, the Court puts to rest - hopefully once and for all - the bad faith legal argument used by polluters to claim that the climate agreements protect them from accountability for climate harms.
🪦R.I.P. Lex Specialis argument in climate justice cases
🪦R.I.P. Lex Specialis argument in climate justice cases
24/ The Court dismisses this argument unequivocally, noting that there is no contradiction between the UN climate agreements and other norms of international law, on the contrary: other legal frameworks are explicitly cited in the UN climate agreement!
July 23, 2025 at 1:45 PM
24/ The Court dismisses this argument unequivocally, noting that there is no contradiction between the UN climate agreements and other norms of international law, on the contrary: other legal frameworks are explicitly cited in the UN climate agreement!
23/ The doctrine of "lex specialis" affirms that when two norms of law contradict one another, the most specific prevails...
Polluting States argued before this Court (& other judicial forums) that this implies that the #ParisAgreement creates a regime of exception.
Polluting States argued before this Court (& other judicial forums) that this implies that the #ParisAgreement creates a regime of exception.
July 23, 2025 at 1:45 PM
23/ The doctrine of "lex specialis" affirms that when two norms of law contradict one another, the most specific prevails...
Polluting States argued before this Court (& other judicial forums) that this implies that the #ParisAgreement creates a regime of exception.
Polluting States argued before this Court (& other judicial forums) that this implies that the #ParisAgreement creates a regime of exception.
19/ ... other international treaties incl. the Ozone Convention and the Desertification Convention. The applicable legal framework further encompasses legal norms and principles of "customary international law" (the Court is mandated by its status to consider such legal norms...)
July 23, 2025 at 1:34 PM
19/ ... other international treaties incl. the Ozone Convention and the Desertification Convention. The applicable legal framework further encompasses legal norms and principles of "customary international law" (the Court is mandated by its status to consider such legal norms...)
18/ The Court lists legal norms that played a key role in its analysis of States' legally binding obligations: starting with the 🇺🇳UN Charter and including "most strictly relevant applicable law" comprising the three UN climate treaties but also encompassing...
July 23, 2025 at 1:28 PM
18/ The Court lists legal norms that played a key role in its analysis of States' legally binding obligations: starting with the 🇺🇳UN Charter and including "most strictly relevant applicable law" comprising the three UN climate treaties but also encompassing...
8/ Jurisidiction (= is the Court competent to address the question): the Court accepts that the questions are legal in nature and that there is no compelling reason for it not to respond to the UNGA = the Court confirms that it will address these legal matters.
July 23, 2025 at 1:10 PM
8/ Jurisidiction (= is the Court competent to address the question): the Court accepts that the questions are legal in nature and that there is no compelling reason for it not to respond to the UNGA = the Court confirms that it will address these legal matters.