The United States is the world’s second-largest greenhouse gas emitter. For that reason, the outcome of the U.S. presidential election in November will have an undeniable impact on the future of the global climate change regime. This is especially the case now that the United Nations’ COP26 Climate Change Conference has been postponed to 2021 as a result of the COVID-19 pandemic. Indeed, as Asia and the rest of the world consider whether and how to step up their levels of ambition as part of the five-year ratchet mechanism of the Paris Agreement, the United States has the potential to be either a catalytic force for that effort going into 2021 or an even stronger spoiler of the Agreement’s ongoing effectiveness at a crucial juncture.

No country will be watching more closely than China. The 2014 U.S.-China Joint Announcement on Climate Change between President Barack Obama and President Xi Jinping proved to be the watershed moment in the lead-up to the Paris Agreement, as the two countries signaled for the first time that they would act in a coordinated manner to combat climate change. Whether the United States and China can recapture that spirit of shared ambition in the future will have ripple effects on the positions of other major emitters as well—especially India, Japan, and Australia, which may not enhance their own levels of ambition without a stronger indication of further action by the United States and China.

While President Donald Trump has begun the process of withdrawing the United States from the Paris Agreement and rolled back domestic and international measures to combat climate change, it is clear that if a Democrat is elected president in 2020, they would make combating climate change a defining priority of their administration. Therefore, a clearer understanding of the specific approach that would underpin the climate diplomacy of a new Democratic president can provide greater reassurance to the international community as countries consider their own levels of ambition in the lead-up to COP26 and beyond.

Throughout the contest for the Democratic presidential nomination, every leading candidate, including the two remaining contenders, Vice President Joe Biden and Senator Bernie Sanders, has supported a domestic Green New Deal framework that would mobilize greater ambition while connecting climate action to key economic and social priorities. For the first time in American political history, polls indicate that climate change is a top priority for Democratic primary voters, and it may be an important factor for general election voters as well. And in another historic first, every major Democratic candidate has published a detailed climate plan, including elements of an accompanying diplomatic strategy.

An analysis of the international elements of these plans makes clear that a future Democratic administration would, at the very least, do the following:

Beyond these common policy prescriptions, perhaps the most consequential question for a new U.S. president will be the degree to which climate change is prioritized by their administration among many other pressing challenges, not least the ongoing public health and long-term economic impacts of COVID-19. Will the fight against climate change be an organizing principle, structurally and substantively, for the entire administration? Will climate change be given legislative priority in Congress, given the potential constraints and challenges to executive authority? And will a new president be able to clearly demonstrate the benefits of global action to a domestic audience? This paper highlights a number of specific considerations, keeping these factors in mind and taking into account the broader global landscape of climate action in which a Democratic president would find themselves.

"The most consequential question for a new U.S. president will be the degree to which climate change is prioritized by their administration among many other pressing challenges."

While President Trump has begun the process of withdrawing the United States from the Paris Agreement, this will not take effect until November 4, 2020— the day after the presidential election. A Democratic president would initiate the process of rejoining the Agreement, with many candidates throughout the presidential primaries having pledged to do so on “day one” of their administration. This process is relatively straightforward: it requires a formal letter of notification to the UN Secretary-General, and under Article 21 of the Paris Agreement, the United States would become a party to the Agreement 30 days later. This rejoining process does not require the approval of other nations.

A more complicated question that will confront a Democratic president is how to handle the Nationally Determined Contribution (NDC) that the United States is obligated to communicate as a party to the Paris Agreement. Formally rejoining the Agreement early in a new administration would likely mean that a new NDC would not yet be fully developed, nor would it be grounded in domestic consultation or able to be leveraged for maximum effect internationally. In such a scenario, a new administration could be presented with several options to uphold the obligation under Article 4 of the Paris Agreement to maintain an NDC. One option would be to provisionally resubmit the Obama administration’s 2025 NDC. Another would be to submit a “placeholder” 2030 NDC (with the final NDC to be submitted at a later date) that could include a floor or range based on domestic and/or international circumstances.

Many of the Democratic candidates to date have provided a sense of the specific level of ambition they would likely communicate in a 2030 NDC. According to models from the Institute for Sustainable Development and International Relations based on data from a 2016 study by Gütschow, et al., the 40 to 60 percent reductions in global greenhouse gas emissions from 2010 levels expressed in the Green New Deal framework would equate to a 43.5 to 62.5 percent cut in U.S. emissions below 2005 levels by 2030. Some candidates, such as Senator Sanders, have expressed much higher targets to cut U.S. emissions by the equivalent of at least 75 percent below 2005 levels by 2030 (71 percent below 2017 levels). It is abundantly clear that a Democratic president would, in the short term, significantly build on the pledge made by the Obama administration to reduce emissions by 26 to 28 percent below 2005 levels by 2025. As a point of comparison, former Republican challenger Governor Bill Weld also pledged to enhance ambition by reducing emissions 39 to 46 percent below 2005 levels by 2030.

"It is abundantly clear that a Democratic president would, in the short term, significantly build on the pledge made by the Obama administration to reduce emissions."

A Democratic president would also seek to enhance long-term ambition. While the Obama administration crafted a long-term strategy to deeply decarbonize the U.S. economy by reducing emissions 80 percent or more below 2005 levels by 2050, a Democratic administration would seek to build on that target based on the latest science and politics. Almost every Democratic candidate to date has pledged to achieve net-zero emissions no later than 2050, including Vice President Biden, who has also spoken of the need to embed any enhanced long-term goal in domestic legislation no later than the end of his first term, including an enforcement mechanism to achieve milestone targets. Senator Sanders’ plan to achieve complete decarbonization of the economy by the same date represents a bold vision that is consistent with the latest climate science.

A Democratic president would launch an aggressive diplomatic effort to encourage other countries to increase their own levels of ambition, especially other major emitters. More than any of his other climate diplomacy plans, Vice President Biden has spoken consistently of his idea to immediately convene a summit of world leaders to enhance ambition in a transparent and enforceable manner, saying that he would do so in his first 100 days—and in one debate—that invitations would be issued on “day one.” This would be a major—and still largely unrecognized—diplomatic moment globally in the fight against climate change, especially in the lead-up to a now postponed COP26. Similar engagements have been proposed by Senator Sanders and others, who have also spoken of the importance of working through the G7 and G20, especially to eliminate fossil fuel subsidies and reform export finance subsidies (see section 4).

Clearly, China will loom large among these major emitters for any Democratic administration. For example, Vice President Biden has spoken frequently of the need to rally other countries as part of an effort to hold China accountable to high environmental standards in Belt and Road Initiative projects, and he has even suggested that this would be a precursor to wider bilateral cooperation with China on climate change and other issues. Other presidential candidates have also embraced this idea, including Governor Weld.

Finally, in order to help hold other countries accountable for their emissions, Vice President Biden has also floated the idea for the State Department to produce a new “Global Climate Change Report” on an annual basis, similar to its Trafficking in Persons Report. Such a report would serve as a mechanism to name and shame countries on the basis of their efforts to combat climate change.

As the United States is the largest economy in the world, arguably the most significant approach that could be adopted by a Democratic president is the commitment to use trade policy as a lever for global climate action. This has been an area of broad consensus among the candidates to date. This includes Vice President Biden’s pledge to condition future trade agreements on countries’ commitments to meet their Paris Agreement targets, or even to renegotiate trade agreements to deliver strong and binding climate standards. The proposal to implement border adjustment fees or quotas on carbon-intensive imports under World Trade Organization rules to promote a level playing field has also been promoted by many of the candidates, including Vice President Biden.

"Arguably the most significant approach that could be adopted by a Democratic president is the commitment to use trade policy as a lever for global climate action."

In terms of exports, establishing a clean technology innovation fund has also attracted broad consensus from candidates. For example, Vice President Biden has pledged to establish a Clean Energy Export and Climate Investment Initiative to promote clean energy exports and investments around the world, prioritizing countries with high-ambition commitments under the Paris Agreement. He has also proposed quadrupling funding for Mission Innovation, an initiative established by the Obama administration and 23 other countries to galvanize research, development, and deployment of breakthrough clean energy technologies.

In addition to their desire for the United States to rejoin the Paris Agreement, perhaps the strongest point of convergence among the Democratic candidates has been their commitment to restore and enhance U.S. international climate finance. Every major candidate said that they would restore U.S. contributions to the Green Climate Fund, with some identifying specific figures, which have ranged considerably in size. For his part, Vice President Biden has emphasized the importance of supporting the Small Island Developing States in the Pacific and Caribbean.

While President Trump has pushed financing for coal and fossil energy projects overseas, it is clear that a Democratic administration would lead efforts to clean up international fossil fuel finance. For example, Vice President Biden has pledged to secure a global commitment to eliminate fossil fuel subsidies by the end of his first term, and to cut domestic subsidies in his first year in office.

"While President Trump has pushed financing for coal and fossil energy projects overseas, it is clear that a Democratic administration would lead efforts to clean up international fossil fuel finance."

Vice President Biden and many of the other candidates to date—including Senator Sanders—have also supported cleaning up overseas finance through the Export-Import Bank (EXIM) and the new U.S. International Development Finance Corporation (DFC) by prohibiting any financing for coal-fired power plants. This is an idea that Governor Weld similarly embraced, calling for the United States to work through both EXIM and the DFC to prohibit financing for overseas coal plants.

Vice President Biden has also suggested that the United States should offer Belt and Road Initiative recipient countries alternative sources of development finance for clean energy investments, and lead an international effort to reform development banks’ rules on countries prioritized for international debt relief on the basis of the climate and debt risks they have undertaken.

A Democratic president would likely not only see climate leadership as limited to the process under the UN Framework Convention on Climate Change. Almost every candidate to date has explicitly highlighted their plan to submit the Kigali Amendment to the Montreal Protocol (which seeks a global phase-down of super-polluting hydrofluorocarbons) for ratification by the U.S. Senate, with some listing it as a priority for their first 100 days. Many candidates hoped the Trump administration would support the amendment—as Governor Weld did—particularly given its widespread support in the American business community.

Vice President Biden has also endorsed biodiversity targets under discussion at the Convention on Biological Diversity, including the national goal to conserve 30 percent of land and water by 2030, which also would serve to protect carbon-dense ecosystems. He has also highlighted the importance of accelerating carbon capture and storage technologies and bolstering enforceable global agreements to reduce emissions from international aviation and shipping through the International Civil Aviation Organization and the International Maritime Organization, respectively.

A Democratic president would prioritize climate change as a security threat more seriously than ever before, mobilizing the Pentagon, national security, and intelligence instruments of their administration to confront the myriad risks it poses.

For example, Vice President Biden would require the secretary of defense and chairman of the Joint Chiefs of Staff to report annually on climate security considerations and would commission a National Intelligence Estimate on the national economic and security implications of climate change. He has also proposed to direct the national security advisor to develop a comprehensive climate security strategy across the Departments of State, Defense, and Homeland Security, among others.

Specific priorities for a Democratic president in global climate security cooperation would include the Arctic region and— potentially—global climate displacement. Vice President Biden has proposed to re-establish climate change as a priority for the Arctic Council and would seek a global moratorium on offshore drilling in the region. By way of contrast, President Trump has signed legislation to open up to the Arctic National Wildlife Refuge to drilling.

A Democratic president would also recognize the need for the U.S. national security community to be a leader in the global energy transition. For example, at a minimum, Vice President Biden has called for increasing the resilience and efficiency of all federal facilities, including the military which accounts for by far the largest percentage of federal government emissions. Senator Sanders, by comparison, has proposed scaling back U.S. military spending that reinforces global oil dependence, and instead heavily investing in research and development to lower emissions.

If a Democratic president takes office in January 2021, addressing the climate crisis will be squarely on their agenda. But the extent to which climate change constitutes an organizing principle of the new administration, and where it falls in the hierarchy of priorities and inevitable political trade-offs, will determine their true impact on the defining global challenge of our time.

In this context, and taking into account the broader global landscape of climate action in which a Democratic president would find themselves, the following are three cross-cutting considerations for a new administration to prioritize as part of their international climate diplomacy strategy.

One of the biggest questions confronting a Democratic president will be how to structure their administration. Among the ideas that have been floated from others besides the presidential candidates is the formation of a new Council on Climate Change within the White House, similar to the existing National Security Council or Council of Economic Advisors, to coordinate interagency policymaking. The structure of the White House drives significant policy change by ensuring top-level buy-in and holding cabinet secretaries accountable for delivering on the president’s agenda, which can help drive a whole-of-government effort.

How the State Department can reorient climate change as an organizing principle of diplomacy and foreign policy is also a key question. Currently, the staff largely responsible for climate change sit within the relatively isolated Bureau of Oceans and International Environmental and Scientific Affairs, with only a small footprint of career Foreign Service Officers. The nominee for secretary of state will clearly be critical to modeling and mainstreaming climate change as a priority throughout the department.

"The structure of the White House drives significant policy change by ensuring top-level buy-in and holding cabinet secretaries accountable for delivering on the president’s agenda."

A new president must also make expertise in and commitment to climate change a clear prerequisite for all other senior nominations and appointments. This includes the secretary of defense and national security advisor, as well as key subcabinet-level positions.

The communication of an enhanced NDC for the United States should be leveraged for maximum impact, both domestically and diplomatically. This means not rushing to submit a new target at the same time that the United States rejoins the Paris Agreement. Instead, an incoming administration should outline a timeline and process to do so that ensures it has the clearest snapshot of U.S. emissions, provides sufficient time for domestic consultation and constituency buy-in, and seeks to engage as well as leverage international partners on the ambition of their own plans in the process. This would also allow time for interagency processes to embed a net-zero emissions target in key policy instruments, including a new midcentury strategy, that would ideally be linked to a regular reporting and enforcement process.

The United States should focus first on major emitters to get the most return for its geopolitical capital. With many smaller emitters already likely to increase their ambitions in the lead-up to COP26, a climate summit of world leaders in early 2021 is only useful if the United States is confident in its position to influence other major emitters specifically to do more. At least initially, a revitalized version of the Major Economies Forum on Energy and Climate Change, which brings together around 20 of the largest emitters and has met previously at the leader level, could prove a well-suited vehicle. However, this must be designed and timed strategically to ensure that it represents an indispensable diplomatic lever to achieve those ends, especially as a key stepping stone towards a rescheduled COP26 and taking into account the United Kingdom’s G7 presidency also, all the while acknowledging the important tone this must strike as the United States seeks to re-enter the international climate fight. Either way, as we noted earlier, a meeting such as this would be a major diplomatic moment that remains relatively underappreciated by the international community at present.

"A Democratic president will need to personally prioritize engagement with China on climate change; the president should avoid doing so purely through a lens of diplomatic or economic combat and should also seek to spur a race to the top."

A Democratic president should also engage with China cooperatively but competitively on climate change at the highest levels. This would start with acknowledging that the U.S.-China relationship has changed fundamentally since 2014, in terms of China’s foreign policy and both countries’ efforts to tackle climate change. A Democratic president will need to personally prioritize engagement with China on climate change; the president should avoid doing so purely through a lens of diplomatic or economic combat and should also seek to spur a race to the top. For instance, the total investment opportunity presented by the renewable energy goals of Belt and Road Initiative recipient countries runs into the hundreds of billions of dollars, thus also providing a major economic opportunity for the American industry. Forums such as the Strategic and Economic Dialogue should be reconstituted and broadened to more specifically address climate change and to provide a basis for regular official-level dialogues, as should federal initiatives in support of subnational cooperation, such as the U.S.-China Climate Leaders Summit that brought together mayors from both countries.

If a Democratic president is inaugurated on January 20, 2021, the United States will inevitably reclaim the mantle of international climate leadership. However, whether this president is able to usher in bold changes internationally and domestically will be determined by a number of factors, including their own hierarchy of priorities and trade-offs, the organization of their administration to deliver this agenda, legislative and judicial constraints on executive power, and their ability to wield influence with the international community to effect pro-climate outcomes.

"While the Paris Agreement’s five-year ratchet mechanism requires countries to update or confirm the level of their 2030 ambition, it is already clear that a number of countries are hedging based on the outcome of the U.S. presidential election."

It is possible that Congress will significantly hamstring the climate ambitions of a Democratic president. Many of the ideas highlighted here will require congressional support, at minimum through the appropriation of funds. While there are major opportunities that can be delivered through executive authority, the changing composition of the U.S. courts also presents potential challenges in this regard. Again, in this context, the relative priority—or, more immediately, political capital—that a Democratic president is willing to expend on climate change will be fundamental to their ability to achieve bold results.

While it has been encouraging to see the depth and breadth of ideas for international climate engagement developed by the various Democratic presidential candidates over the last 18 months—particularly Governor Jay Inslee, Senator Elizabeth Warren, Mayors Pete Buttigieg and Michael Bloomberg, as well as Tom Steyer—the ability to implement these ideas will depend to no small extent on these factors.

Regardless, the rest of the world is watching closely. While the Paris Agreement’s five-year ratchet mechanism requires countries to update or confirm the level of their 2030 ambition, it is already clear that a number of countries are hedging based on the outcome of the U.S. presidential election. This is the case despite a targeted and systematic diplomatic effort by the UN Secretary-General and the United Kingdom as the incoming president of COP26. With COP26 now delayed until 2021, this hedging is likely to intensify, including in light of the radically changed economic circumstances the world finds itself in as a result of the COVID-19 pandemic. Therefore, a clearer understanding of the likely policies of a future Democratic president can help provide a greater degree of reassurance to the international community throughout this period.

However, if President Trump is reelected, all bets are off, besides the fact that the United States will have formally withdrawn from the Paris Agreement at a critical moment for its effectiveness. Even with the irreversible and accelerating momentum of the real economy and efforts to provide reassurances about U.S. subnational contributions, there is no sugarcoating the fact that this outcome would hold significant consequences for the global climate regime. This is especially true for the efforts of other major emitters, including China and the rest of Asia.

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