07 April 2026
CO26071 | The UN Climate Regime and the US Withdrawal
SYNOPSIS
The Trump administration announced the US withdrawal from the international climate regime earlier this year. One possible explanation lies in the growing influence of the IPCC’s scientific authority in domestic spheres, which may have altered the perceived costs and benefits of continued participation. Despite the US absence, the UNFCCC remains an important platform for international climate cooperation.
COMMENTARY
The US was among the first industrialised countries to ratify the United Nations Framework Convention on Climate Change (UNFCCC) in 1992. This demonstrates the US recognition of its value in addressing collective action problems related to climate issues. More broadly, regime theory suggests that powerful states, such as the US, tend to exert influence on the structure of international cooperation in ways that advance their interests.
Yet, in early 2026, the Trump administration announced the US withdrawal from the UNFCCC and the Intergovernmental Panel on Climate Change (IPCC), along with more than sixty other international institutions, claiming that they no longer served US interests. What has changed since the early years of the climate regime? Does the US withdrawal diminish the relevance of the UNFCCC?
The US and the UNFCCC
The US position in the international climate regime has historically involved compromises. Differences with other major industrialised countries were already evident in the early pre-negotiation phase, notably at the 1989 Noordwijk ministerial meeting, where the US resisted European countries’ proposal for binding emission targets and schedules. It preferred a more flexible approach centred on developing scientific research and national strategies.
Although the eventual design of the UNFCCC as a framework convention reflected a compromise closer to US preferences, subsequent developments often challenged the US position.
The 1997 Kyoto Protocol was a case in point. By imposing legally binding emission-reduction targets only on developed countries, the Protocol conflicted with the US long-standing concerns that climate mitigation measures could harm its economy and undermine its economic competitiveness, especially since developing countries such as China and India were exempt from these targets.
Although the US signed the Protocol in 1998, neither the Clinton nor the subsequent Bush administration submitted it for ratification by the US Senate. This followed the 1997 Byrd-Hagel Resolution, in which the US Senate unanimously rejected the Protocol terms in a 95-0 vote, leading to its non-ratification and the US’ subsequent pullout from the Protocol.
Although it had to compromise on some of its preferences and interests, the United States remained involved with the UNFCCC for more than three decades, even after the Trump administration withdrew from the Paris Agreement in 2017. Why then did the United States ultimately decide to withdraw from the convention itself?
The IPCC Influence and Divided US Climate Views
Conventional explanations might point to interstate bargaining and shifting national interests within the regime, or to changes in domestic political leadership and policy priorities. While climate change has long been a contentious issue in US domestic politics, the second Trump administration has distanced itself from climate matters more aggressively by not only branding it a hoax, but also by taking concrete measures to slow renewable energy expansion. This is evident in the recent compensation offer of nearly US$1 billion to TotalEnergies for abandoning its offshore wind projects and redirecting its investments toward fossil fuel development in the US.
Although the Trump administration’s rejection of climate change frameworks provides the broader context for the withdrawal, it does not fully explain why the US chose to exit the UNFCCC rather than simply adjusting its domestic policies while remaining within the regime.
One possible explanation lies in the growing influence of the IPCC’s epistemic authority in the domestic sphere. The IPCC’s scientific assessments play a central role in informing and shaping international climate cooperation. Over time, the IPCC has established widely recognised benchmarks such as the 1.5°C and 2°C global temperature goals for the end of the century, which have shaped global and national climate policy debates.
The IPCC findings have circulated beyond diplomatic settings and entered the US domestic debates through various channels, including the Congressional Research Service briefs to lawmakers and media coverage. As they became more deeply embedded in domestic spheres, they increasingly influenced policy expectations against which the government is evaluated and heightened the government’s exposure to greater reputational and accountability risks.
Furthermore, among the increasing number of climate litigation cases in the US, the IPCC is frequently referenced, including in cases brought by youth groups against the federal government and in cases involving fossil fuel companies and federal regulatory agencies. This illustrates how internationally produced scientific consensus intersects with longstanding domestic contention over climate issues.
In such an environment, continued participation in the UNFCCC may carry increasing political implications, as it implicitly signals acceptance of certain policy directions based on IPCC assessments, which might garner support from some constituencies while provoking opposition from others domestically. Withdrawing from the UNFCCC and the IPCC thus distances the country from the epistemic authority through which those policy directions are communicated, granting the government greater autonomy to handle domestic climate-related issues.
Does the UNFCCC Still Matter?
As one of the world’s largest greenhouse gas emitters and a historically significant contributor to the development and funding of global climate governance, the US departure inevitably affects both the UNFCCC’s financial resources and its political credibility. While Bloomberg has previously offered to cover the UNFCCC budget shortfall caused by the US, questions remain about the regime’s future relevance in fighting climate change.
At the same time, the US exit could weaken collective momentum. Other countries may see it as more difficult to meet climate mitigation targets without the formal participation of a major emitter in the regime, which may also discourage them from remaining committed to the agenda.
While such concerns are justified, the withdrawal of a single member, even a powerful one, does not necessarily undermine the value of the climate regime, which continues to provide benefits to participating states by facilitating cooperation and interactions, reducing the costs of policy coordination, and providing platforms for information exchange.
The scientific consensus reflected in IPCC reports remains instrumental in informing global discussions on climate mitigation pathways. It serves as a key reference point for countries when formulating and updating their national climate strategies. In other words, the broader institutional framework of the cooperation remains intact despite the US absence.
In addition, it is important to recognise that the UNFCCC is only one component in the broader landscape of global climate governance. Climate action increasingly takes place across multiple institutional levels and networks, including city-level initiatives, regional cooperation mechanisms, financial institutions, and transnational partnerships.
Platforms such as the C40 demonstrate how local governments in different countries collaborate and promote mitigation efforts even when national policies differ. This more polycentric structure of climate governance means that progress on climate action does not depend solely on the participation of any single country within the UNFCCC framework.
For Southeast Asian countries, this suggests that continued engagement with the UNFCCC remains worthwhile. Additionally, regional actors might benefit from supplementing their UNFCCC participation with engagement in other forms of climate cooperation. Such diversification can help ensure that climate action continues to move forward even amid shifts in global political leadership and changes in great power participation.
About the Author
Margareth Sembiring is a Research Fellow at the Centre for Non-Traditional Security Studies (NTS Centre), S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University (NTU), Singapore.
SYNOPSIS
The Trump administration announced the US withdrawal from the international climate regime earlier this year. One possible explanation lies in the growing influence of the IPCC’s scientific authority in domestic spheres, which may have altered the perceived costs and benefits of continued participation. Despite the US absence, the UNFCCC remains an important platform for international climate cooperation.
COMMENTARY
The US was among the first industrialised countries to ratify the United Nations Framework Convention on Climate Change (UNFCCC) in 1992. This demonstrates the US recognition of its value in addressing collective action problems related to climate issues. More broadly, regime theory suggests that powerful states, such as the US, tend to exert influence on the structure of international cooperation in ways that advance their interests.
Yet, in early 2026, the Trump administration announced the US withdrawal from the UNFCCC and the Intergovernmental Panel on Climate Change (IPCC), along with more than sixty other international institutions, claiming that they no longer served US interests. What has changed since the early years of the climate regime? Does the US withdrawal diminish the relevance of the UNFCCC?
The US and the UNFCCC
The US position in the international climate regime has historically involved compromises. Differences with other major industrialised countries were already evident in the early pre-negotiation phase, notably at the 1989 Noordwijk ministerial meeting, where the US resisted European countries’ proposal for binding emission targets and schedules. It preferred a more flexible approach centred on developing scientific research and national strategies.
Although the eventual design of the UNFCCC as a framework convention reflected a compromise closer to US preferences, subsequent developments often challenged the US position.
The 1997 Kyoto Protocol was a case in point. By imposing legally binding emission-reduction targets only on developed countries, the Protocol conflicted with the US long-standing concerns that climate mitigation measures could harm its economy and undermine its economic competitiveness, especially since developing countries such as China and India were exempt from these targets.
Although the US signed the Protocol in 1998, neither the Clinton nor the subsequent Bush administration submitted it for ratification by the US Senate. This followed the 1997 Byrd-Hagel Resolution, in which the US Senate unanimously rejected the Protocol terms in a 95-0 vote, leading to its non-ratification and the US’ subsequent pullout from the Protocol.
Although it had to compromise on some of its preferences and interests, the United States remained involved with the UNFCCC for more than three decades, even after the Trump administration withdrew from the Paris Agreement in 2017. Why then did the United States ultimately decide to withdraw from the convention itself?
The IPCC Influence and Divided US Climate Views
Conventional explanations might point to interstate bargaining and shifting national interests within the regime, or to changes in domestic political leadership and policy priorities. While climate change has long been a contentious issue in US domestic politics, the second Trump administration has distanced itself from climate matters more aggressively by not only branding it a hoax, but also by taking concrete measures to slow renewable energy expansion. This is evident in the recent compensation offer of nearly US$1 billion to TotalEnergies for abandoning its offshore wind projects and redirecting its investments toward fossil fuel development in the US.
Although the Trump administration’s rejection of climate change frameworks provides the broader context for the withdrawal, it does not fully explain why the US chose to exit the UNFCCC rather than simply adjusting its domestic policies while remaining within the regime.
One possible explanation lies in the growing influence of the IPCC’s epistemic authority in the domestic sphere. The IPCC’s scientific assessments play a central role in informing and shaping international climate cooperation. Over time, the IPCC has established widely recognised benchmarks such as the 1.5°C and 2°C global temperature goals for the end of the century, which have shaped global and national climate policy debates.
The IPCC findings have circulated beyond diplomatic settings and entered the US domestic debates through various channels, including the Congressional Research Service briefs to lawmakers and media coverage. As they became more deeply embedded in domestic spheres, they increasingly influenced policy expectations against which the government is evaluated and heightened the government’s exposure to greater reputational and accountability risks.
Furthermore, among the increasing number of climate litigation cases in the US, the IPCC is frequently referenced, including in cases brought by youth groups against the federal government and in cases involving fossil fuel companies and federal regulatory agencies. This illustrates how internationally produced scientific consensus intersects with longstanding domestic contention over climate issues.
In such an environment, continued participation in the UNFCCC may carry increasing political implications, as it implicitly signals acceptance of certain policy directions based on IPCC assessments, which might garner support from some constituencies while provoking opposition from others domestically. Withdrawing from the UNFCCC and the IPCC thus distances the country from the epistemic authority through which those policy directions are communicated, granting the government greater autonomy to handle domestic climate-related issues.
Does the UNFCCC Still Matter?
As one of the world’s largest greenhouse gas emitters and a historically significant contributor to the development and funding of global climate governance, the US departure inevitably affects both the UNFCCC’s financial resources and its political credibility. While Bloomberg has previously offered to cover the UNFCCC budget shortfall caused by the US, questions remain about the regime’s future relevance in fighting climate change.
At the same time, the US exit could weaken collective momentum. Other countries may see it as more difficult to meet climate mitigation targets without the formal participation of a major emitter in the regime, which may also discourage them from remaining committed to the agenda.
While such concerns are justified, the withdrawal of a single member, even a powerful one, does not necessarily undermine the value of the climate regime, which continues to provide benefits to participating states by facilitating cooperation and interactions, reducing the costs of policy coordination, and providing platforms for information exchange.
The scientific consensus reflected in IPCC reports remains instrumental in informing global discussions on climate mitigation pathways. It serves as a key reference point for countries when formulating and updating their national climate strategies. In other words, the broader institutional framework of the cooperation remains intact despite the US absence.
In addition, it is important to recognise that the UNFCCC is only one component in the broader landscape of global climate governance. Climate action increasingly takes place across multiple institutional levels and networks, including city-level initiatives, regional cooperation mechanisms, financial institutions, and transnational partnerships.
Platforms such as the C40 demonstrate how local governments in different countries collaborate and promote mitigation efforts even when national policies differ. This more polycentric structure of climate governance means that progress on climate action does not depend solely on the participation of any single country within the UNFCCC framework.
For Southeast Asian countries, this suggests that continued engagement with the UNFCCC remains worthwhile. Additionally, regional actors might benefit from supplementing their UNFCCC participation with engagement in other forms of climate cooperation. Such diversification can help ensure that climate action continues to move forward even amid shifts in global political leadership and changes in great power participation.
About the Author
Margareth Sembiring is a Research Fellow at the Centre for Non-Traditional Security Studies (NTS Centre), S. Rajaratnam School of International Studies (RSIS), Nanyang Technological University (NTU), Singapore.
