US politics has long shaped global climate action and science – how much will Trump’s opposition matter?
US president-elect Donald Trump has indicated that he will again withdraw his country from the Paris agreement and perhaps the UN climate process altogether. The uncertainty this has created was palpable in the negotiation rooms and hallways of the Cop29 climate summit in Baku, Azerbaijan, where I wrote this.
I have studied the Intergovernmental Panel on Climate Change (IPCC) and its global assessments of scientific knowledge for over 15 years and have followed how its most recent reports are being used in official climate negotiations. As I document in my book, the US and its domestic politics has influenced the organisation of global climate science, and the climate agreements that depend on it, since the IPCC was established in 1988.
From the outset, proposals from the US were influential in the design of a specifically “intergovernmental” body to provide the world with climate science, rather than one lead by scientists themselves. This gave governments a central role in the organisation and its assessment process. Most notably, governments had line-by-line approval of the most read component of the thousand page IPCC reports: the much shorter Summary for Policymakers.
In the second round of the IPCC’s assessment reports in the 1990s, climate scepticism in the US would shape how one of the most important sentences was received – sowing uncertainty that facilitated president George W. Bush’s rejection of the Kyoto protocol, a precursor to the Paris agreement.
In 1996, the IPCC concluded that “the balance of evidence suggests that there is a discernible human influence on global climate”. Controversy around the scientific veracity of this finding was initiated by an op-ed in the Wall Street Journal, in which an American physicist accused the lead authors of corrupting the IPCC peer-review process.
This uncertainty was mobilised in a 1998 anti-Kyoto protocol petition, which indicated that there was “no convincing evidence” that human release of greenhouse gases will cause “catastrophic heating of the Earth’s atmosphere and disruption of the Earth’s climate”.
In 2000, soon after taking office, president Bush rejected the Kyoto protocol because, he said, it exempted 80% of the world. In a letter justifying the move, he also cited incomplete knowledge of climate science.
The Bush administration’s hostility to climate science would shape IPCC reports throughout the 2000s. Scientists adopted new methods for evaluating scientific uncertainty and ensured a clear line of sight between the main reports and their summaries. For some this made for conservative reports, for others it laid incontestable ground for international climate policymaking.
Put to the test by Trump
The drafting and implementation of the 2015 Paris agreement took place within this context and with US politics firmly in view. An agreement was crafted that would not need senate approval and which depended on national pledges and collective reviews. The strength of this architecture was immediately put to the test during the first Trump presidency.
The IPCC’s sixth assessment cycle, which began in 2015, was set to be its most ambitious and costly round of reports. It would play a pivotal role in implementing the Paris agreement by providing the best available science for the “global stocktake”, where countries assess collective progress towards meeting the long term temperature goal.
However, on taking office, Trump withdrew funding from the organisation, creating a large budget shortfall. When a hugely influential special report on the impacts of warming at 1.5°C was published in 2018, the US government along with Saudi Arabia, Russia and Kuwait, initiated a political struggle when they refused to formally welcome the report at that year’s climate summit in Poland.
We cannot depend on the US
The Paris agreement attempted to bring science from the IPCC and political negotiation at UN climate talks closer together so that parties could be responsive to the latest knowledge and increase collective ambition over time.
This change in US administration is likely to strengthen efforts by some countries to undo this closer alignment between climate science and politics. The wrangling over the IPCC was on view in the first week of Cop29, as countries wrestled over language to identify the IPCC’s role in the second global stocktake.
However, climate action has always been about more than one state. Once Kyoto failed, the architects of the Paris agreement understood that the collective response can never be dependent on the US. Some researchers have observed that, if anything, Trump’s first attempt to withdraw the US from the Paris agreement strengthened it.
Even if this time around Trump withdraws from the entire UN climate convention, the US is likely to maintain influence over the process, as it does other global environmental treaties such as the convention on biological diversity.
Trump’s election still matters, of course. It slows and delays the transition from fossil fuels and increases the accumulation of greenhouse gases in the atmosphere. A more muted US presence was already detectable in the Cop29 negotiating rooms that I observed.
Trump matters to climate politics, yes. But so does everyone else on the planet, and it is that which is most important to keep in view.
Don’t have time to read about climate change as much as you’d like?
Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 40,000+ readers who’ve subscribed so far.
Hannah Hughes receives funding from UK Economic and Social Research Council (ESRC) and the British Academy. She is co-investigator on the ESRC funded study of the IPCC, “The Politics of Science in International Climate Cooperation” (ES/W001373/1). She is principal investigator on the British Academy ODA interdisciplinary project of COP30 "Centring Climate Agreement-Making in and from the Amazon Rainforest" (OIIRP230289).