As the two largest greenhouse gas emitters, the United States and China currently hold immense influence over the trajectory of the world’s climate.
Scientists are grappling with the far-reaching repercussions of global warming as new climate disasters unfold each year. The 2020s alone have produced the three hottest years on record. In January 2025, wildfires in southern California were among the costliest and deadliest in the state’s history. That same year, flooding in northern China forced the evacuation of hundreds of thousands of citizens. Climate change is a reality that neither country can afford to ignore.
Both China and the United States have recognized their individual and collaborative significance in reducing emissions. Since the U.S.-China joint announcement on their respective national climate goals, which paved the way for the 2015 Paris Agreement, climate change has occupied a unique position in U.S.-China relations: a looming threat that has become one of the most consistent points of close collaboration amid otherwise fiercely competitive relations.
That cooperation now sits at a crossroads. While climate change promises unprecedented environmental and health impacts, efforts to address it remain heavily influenced by the geopolitical tensions between the two countries.
“When you’re living in a place that has really bad air pollution, you can’t escape it,” said Kate Logan, director of the Asia Society’s China Climate Hub. Logan traced much of China’s climate momentum to its ‘war on air pollution,’ one of the country’s major environmental turning points. At its most severe, air pollution in 2013 was PM2.5 particles per cubic meter—over 10 times the safe limit set by the World Health Organization (WHO). During this time, Logan saw firsthand how the visible effects of climate change forced a crucial shift in China’s climate change discussion and action.
Logan described air pollution as a catalyst for China’s pro-climate measures and for public understanding of the necessity of quick and effective action. This pollution demanded climate action due to its direct health consequences—and air pollution still causes 2 million deaths per year in China, according to the WHO.
Logan emphasized air pollution’s impacts on all groups of people as particularly noteworthy. “I think that’s really important, because it makes air pollution a shared challenge that’s really unifying in terms of garnering a public interest in responding to it,” she commented.
The public interest and awareness look strikingly different on either side of the Pacific. In 2020, researchers at the European Investment Bank found that 73% of Chinese citizens viewed climate change as a “major threat to society,” compared to only 39% of U.S. citizens. In spring 2025, over 1 in 4 Americans reported that they do not believe climate change is largely caused by human activity, according to the Yale Program on Climate Change Communication. While China framed climate change mitigation as a development opportunity, in the United States, it became a source of polarization.
In part due to this investment, intense focus on improving air quality brought green technology to the forefront on the international stage. Katie Lebling, senior associate at the World Resources Institute’s U.S. Climate Program, claims her interest in linking American and Chinese climate policy came from her time in Beijing. “You could more tangibly see the environmental impacts of development there than you could in the U.S., where I was living. So that kind of made me interested in bringing the two threads together.”
And yet, despite differences in public recognition of climate change and views on climate mitigation and adaptation strategies, both countries must take calculated, decisive action to avoid the worst impacts of global warming.
According to Weila Gong, scholar at UCSD and author of Implementing a Low-Carbon Future: Climate Leadership in Chinese Cities, “U.S.-China relations are really important because they are the world’s most important economies in terms of their size as well as their carbon emission levels. So, it’s very hard to achieve any substantial progress without some level of collaboration.”
“Dealing with climate change is not just an environmental problem. It’s also a development challenge. So I think that kind of renewed attention on green development strategies actually opens up opportunities to think about what we can learn.”
With the drastic differences in climate change understanding between the two countries, alongside their intense technological and economic competition, is U.S.-China climate development collaboration even feasible?
Climate research and technology collaborations offer key insight into the possibility and importance of this continued cooperation.
This research partnership has been expansive on a number of fronts throughout the past couple of decades and has become increasingly critical. Global temperatures continue to rise, approaching the 1.5 C limit set by the Intergovernmental Panel on Climate Change (IPCC) to avoid the most catastrophic impacts of climate change, with 2024 being the first year to exceed this threshold. Therefore, climate change research and collaboration dialogues have shifted—rather than solely focusing on reducing emissions at the source, dealing with atmospheric carbon dioxide has become increasingly important.
Through the Clean Energy Research Center, a former joint initiative between the U.S. Department of Energy and China’s Ministry of Science and Technology, researchers collaborated on clean energy vehicles and reported findings on potential CO2 storage sites in the Ordos Basin and Rock Springs Uplift. The Ordos Basin has since become a critical site in China for carbon sequestration (the storage of carbon dioxide to reduce greenhouse gases), helping China come closer to achieving its carbon peaking and neutrality goals.
A 2022 collaboration between Tsinghua University and UCLA compared China’s national emissions trading system (ETS) and the Hubei pilot program to California’s cap-and-trade system, all of which place a price on carbon to encourage emissions offsetting. This offered timely insight into the world’s largest emissions trading system, covering 60% of China’s CO2 emissions, and one of the most comprehensive cap-and-trade systems, covering 75% of California’s GHG emissions.
In doing so, they increased transparency of the impacts of these systems and provided recommendations for carbon market reform and potential improvements. One suggestion that emerged from this research was for China’s national ETS to transition to a cap-and-trade system. Alongside further research clarifying the benefits and drawbacks, this actually became a reality: China now plans to implement a cap-and-trade system by 2030, including an absolute cap on emissions for a variety of sectors.
Gong, whose research largely focuses on the low-carbon transition through similar systems, expressed her hope that subnational collaboration such as this continues. “There is still research being produced,” she said. “Academics have common interests, not only in U.S.-China relations or cooperation, but they keep working on climate policy and related science on climate change.”
Logan agrees. “Unlike other areas of engagement in the U.S.-China relationship, such as the economy, where the end goals of both sides are different, climate is a global public good. So there’s very clear alignment in terms of the technical-level research.”
This alignment is not just symbolic. Hengrui Liu, a postdoctoral scholar at Tufts’s Climate Policy Lab, described the various advantages of research collaborations. “I think a lot of the time when we are talking about the environment, we’re only talking about environmental benefits. The U.S.-China cooperation could lead to more green tech collaborations. This kind of stuff can create jobs. It’s good for the economy, good for us consumers.”
Liu attended COP26 and COP27, the Conferences of the Parties held in 2021 and 2022, respectively. These events, hosted by the United Nations Framework Convention on Climate Change, put emissions reduction at the center of international climate change discussion. Through his experience, Liu observed that U.S.-China cooperation is not just important for these two countries but also shapes how the rest of the world behaves. In creating the U.S.-China joint announcement and signing the Paris Agreement, they incentivized other countries to join so that the agreement would take effect. “Their actions set examples for both developed and developing countries.”
As much as this collaboration promises a multitude of benefits, the two countries now operate in opposite lanes, making meaningful partnership seem like a thing of the past.
Yanran Xu, an Associate Professor and master’s supervisor at Renmin University’s School of International Relations in Beijing, believes that cooperation can still happen regardless of geopolitical tensions. She commented that in the U.S. Department of Energy, “No matter how you switch presidents, there are still a bunch of people who work very regularly and routinely for the goals, for renewable energies, for climate change.”
Even in the face of these conflicting short-term goals, Xu remains optimistic about the long-term continuation of this collaboration. Xu compared U.S.-China climate relations to an economic cycle, with periods of downturn followed by recovery. “Every 10 years, there will be a change…I think there’s still room for China and the U.S. to work on this.”
Lebling maintains cautious hope. “There’s so much momentum still happening in the U.S., even with the federal rollback of these policies, I don’t think that’s going to be stopped entirely. I think it will be potentially slowed down…[but] we’re in a more advanced situation with the energy transition.”
The increasing severity of climate change in the midst of insufficient action has led to reliance on new technologies such as carbon removal and sequestration, making continued and emerging collaboration even more necessary. “There isn’t really a space where countries can come together and talk about carbon removal, which I think is really needed because it is so not well understood,” Gong said. “And, yeah, there’s a lot of questions around the mitigation deterrence piece…how do you make sure that you’re minimizing negative impacts and maximizing benefits across all these different approaches?”
Alternatively, Logan argues that China’s rapid green-tech expansion provides a critical time to shape a new kind of climate collaboration between China and the United States—if politics do not get in the way.
“Part of what I worry about is that those who are supportive of clean energy and don’t like the Trump administration will push back against ways that we could constructively engage with Chinese technologies. Actually I think that one of the best pathways forward is finding ways for us to enable Chinese technologies to be incorporated into investments locally, in partnership with American companies in ways that create local jobs but also accelerate the ability of U.S. actors to deploy clean energy in the U.S. rather than blocking all Chinese technologies.”
In the midst of escalating international tension, developing these clear paths forward is imperative.
For Liu, communication and cross-cultural correspondence will remain key. He remarked that academic exchanges are especially noteworthy bridges between the U.S. and China. “They help the politicians understand what is going on. And those are the biggest contributions.”
Maintaining this is rooted in deepening insight into both countries. Liu added, “If we want to understand China, we should have more people who know Chinese languages, right? Either American students who study Chinese languages, or having Chinese students incorporate them into the conversation, into the group, and then we have a better understanding of each other.”
Logan added, “It’s really important for the U.S. to continue cultivating knowledge and expertise about China across all domains of a relationship…Because one of the most important aspects in stabilizing a relationship is mutual understanding.”
Whichever path both countries choose, mutual understanding is essential to advance this necessary collaboration. One thing is for certain—throughout the next phase of U.S.-China relations, climate change will remain a constant and common enemy.