Since the 1990s, Europe has relied on this solid base to play a leading role in the emerging global climate regime. This has been critical in shaping the European Union's identity and incipient foreign policy as a normative power engaged in multilateral diplomacy to shape the international agenda. Following decades of laborious negotiations, the international community finally reached a new accord to tackle climate change during the 21st Conference of the Parties (COP) held in Paris in 2015. The so-called 'Paris Agreement', signed by 195 countries, represents the most comprehensive and far-reaching climate accord ever achieved. Consequently, President Trump's decision to withdraw the United States from the Paris Agreement in June 2017 sent shockwaves through the international community[2]. How should the EU respond to this setback? This paper will provide recommendations on how Europe can and should become the guardian of the Paris Agreement. The first part of the paper will focus on the historical context of Europe's role in climate diplomacy up to the Paris Agreement. The second section will analyze the strengths and weaknesses of EU and member state environmental policies, demonstrating how Europe is committed to lead by example, inciting further international climate action. The last section will examine how leading by example will provide Europe with the authority to position itself at the heart of the global climate regime, building a network of robust partnerships with countries around the world to compensate for US disengagement.

1. The historical context

From the Cold War to the Kyoto Protocol

Until the ending of the Cold War, the United States was the uncontested leader of the nascent international environmental regime, with Europe relegated to the sidelines. This was due firstly to Cold War dynamics, whereby Washington would have never allowed the European Economic Community (EEC) to claim leadership within the Western block, even on the issue of environmental protection. Moreover, the EEC was hampered by the lack of a legal base for environmental policy in the founding treaties; this, along with the requirement for unanimity in the Council, often paralyzed the Community. Several important changes allowed for a reversal of this situation. Firstly, as the US shifted to neoliberal economic policies generally hostile towards regulation of any sort, it gradually abandoned its leadership role on the environment, leaving a vacuum that the EU was able to fill. Secondly, the 1986 Single European Act (SEA) provided the EEC with an autonomous legal base for environmental policy, including internal legislation and external relations. Likewise, the 1992 Maastricht Treaty created the European Union, introduced qualified majority voting on environmental issues, and initiated the co-decision procedure involving both the Council and the European Parliament, which facilitated the ratification of more ambitious legislation. Thirdly, the ending of the Cold War galvanized world politics during the 1990s. The US no longer sought to overshadow the EU in environmental negotiations, and the UN became less prone to paralysis, opening the door for new global action in a variety of fields. Indeed, from the early 1990s until the Obama Presidency, the EU became the uncontested leader of the international environmental regime[3].

The EU's most impressive achievement remains its critical role in the development of the Kyoto Protocol, which entered into force in 2005. The Protocol established a legally binding framework for the UNFCCC, involving clear differentiated targets and timetables for cutting GHG emissions depending on each country's level of development. Nonetheless, the Protocol faced staunch American opposition under President Bush Jr., who not only refused to ratify it, but sought to actively undermine it. It was at this moment that the EU demonstrated leadership by galvanizing the international community to proceed without the US. The EU took a significant risk, as there was no guarantee other nations would follow its lead. In fact, the EU succeeded not only in turning the Kyoto Protocol into a functioning accord, but also in meeting the requirement that the total number of signatories must be responsible for at least 55% of global GHG emissions. In order to implement these international commitments, the EU began to expand the scope of its internal environmental legislation. In 1998, it launched an internal burden-sharing agreement colloquially known as the 'EU bubble', which required higher emissions cuts from developed member states, while providing less developed countries with more leeway. Moreover, in 2005, the EU developed the Emissions Trading System (ETS), which became its main tool for delivering commitments under the Kyoto Protocol, and represented the world's first international carbon trading system.

From Copenhagen to the Paris Agreement

During the mid-2000s, the EU began to push for a more comprehensive climate agreement, as it became clear that Kyoto targets, even if implemented by all parties, would be insufficient. Many developing countries, especially the BRICS nations (Brazil, Russia, India, China and South Africa), had become major GHG emitters without committing to binding Kyoto targets, with China surpassing the US in 2007 as the world's largest emitter. Once again, the EU provided exemplary leadership with a new 'climate and energy package' in 2008, setting binding targets that included a 20% cut in GHG emissions (from a 1990 baseline), as well as a 20% share for renewable energies and energy efficiency, to be achieved by 2020. Therefore, marginalization of the EU during the 2009 Copenhagen Summit came as a surprise. Despite model pledges by European states, the final agreement was essentially a symbolic and ineffectual deal between the US and China supported by the other BRICS countries. Although the Copenhagen Agreement contained some positive provisions such as the official recognition of the 2°C threshold, it failed to establish binding pledges, targets or timetables to effectively address climate change. There are many factors explaining the EU's debacle at Copenhagen, including the reassertion of US leadership under President Obama, as well as the general rise to prominence of the BRICS countries. Despite this setback, the EU confounded expectations by responding vigorously to redouble its efforts both in terms of domestic environmental legislation and climate diplomacy. Europe succeeded in re-establishing a leadership role in subsequent COPs, including the Durban Summit in 2011, where the EU played a critical role in brokering an agreement known as the 'Durban Platform'. The latter set the guidelines that would eventually lead to the Paris Accord, a new comprehensive climate agreement that involved the US, the BRICS and other developing countries.

France, as the host of the COP21 in 2015, together with its European partners, was determined not to repeat the mistakes of Copenhagen. Indeed, the outcome was more successful than many had anticipated, as the conference established a structure for global climate governance signed by 195 countries. Of all the major parties, European states were most insistent on establishing timely and verifiable national emissions pledges that would be sufficient to provide mutual trust in order to achieve an ambitious agreement. The EU played the role of a mediator and was instrumental in building bridges between the development needs of the global South and more stringent climate demands from the developed North. For example, the EU began the conference by announcing a joint strategy with 79 African, Caribbean and Pacific (ACP) countries, and European delegates played a leading role in building a 'coalition of high ambition' that involved the US. This coalition successfully pushed for the inclusion of a commitment to contain global mean temperatures to a 1.5 °C increase over the course of the century, as well as the establishment of a new 'transparency framework'. The latter's purpose is to review the 'intended nationally determined contributions' (INDCs) of all parties, with subtle variations in expected efforts between developed and developing countries. 2023 was agreed to as a starting date for the first five-yearly 'global stockade' to review the adequacy of national efforts, regularly updating and enhancing them in the process. Although far from perfect[4], the Paris Agreement arguably represents the best opportunity to address climate change, and Europe can take credit for its instrumental role in making the COP21 a success.

2. Internal environmental policy: leading by example

EU climate and energy policies

US withdrawal from the Paris Agreement represents an opportunity for Europe to redouble internal efforts to implement current climate commitments and perhaps even surpass them. This is essential in order to send a strong signal to other countries that Europe is determined to assume a key role in safeguarding the accord. The robust condemnation that followed Trump's decision may result in greater climate action, both within Europe and internationally. If Europe succeeds in setting the example, this may encourage other major GHG emitters such as China, India, or Brazil, to maintain their climate pledges. So far, the global response has been encouraging. Indeed, all other parties to the Paris Agreement have indicated that they remain committed to implementing their climate pledges, as was made clear during the G20 Summit held in Hamburg (July 2017). Nevertheless, this is no reason for complacency, as the global climate regime remains fragile; the positive response that followed Trump's withdrawal announcement will need to be sustained in the years to come.

The EU's main contribution to the COP21 is known as the '2030 climate and energy framework', announced by the EU Council in October 2014. Building on the 2020 'climate package'[5], the framework contains ambitious targets to be achieved by the year 2030, including at least 40% cuts in GHG emissions (from a 1990 baseline) and at least 27% for the share of renewable energies and energy efficiency. The EU's main tool for achieving these targets relies on reforming the ETS with new indicators for competitiveness, including price differences with major trading partners, as well as better coordination between member states on carbon pricing. Sectors covered by the ETS, mostly power generation, industry and some parts of the aviation sector, will have to cut emissions by 43% (from a 2005 baseline). Non-ETS sectors, such as agriculture, housing, transport and waste, will have to cut emissions by 30%, to be converted into individual targets by member states. Moreover, the EU has also put together a so-called 'roadmap for a low carbon economy', which outlines a series of general targets to be met by 2050. These include a minimum 80% cut in GHG emissions (from a 1990 baseline), with an intermediate target of 60% by 2040. The roadmap underlines that all sectors of the economy will need to contribute, but that variations in emission cuts can occur between different sectors depending on their technological and economic situation. These are very ambitious targets, and taken together, represent some of the most extensive pledges announced by any group of countries before, during or after the COP21.

Nonetheless, while impressive, EU legislation has its flaws, and Europe has the potential to go further on climate action. For example, the 2050 low-carbon economy roadmap does not contain a commitment for reaching carbon neutrality[6]. This is problematic, since many scientists agree that in order for global warming to remain below the 2°C threshold, all developed countries will need to reach carbon neutrality by mid-century (and developing countries by the end of the century). Likewise, the 2050 roadmap does not contain sufficiently precise indications of how the outlined targets are to be achieved over the long run; it also lacks specific targets for increasing renewable energy and energy efficiency. Thus, the EU needs to integrate the objective of carbon neutrality by mid-century, flesh-out the 2050 roadmap with more detailed policies across different sectors, and provide clear targets for the energy sector. Moreover, the ETS has been beset with internal problems since its launch in 2005, and even today, due in part to surplus allowances and low fuel prices, it has not performed as intended, with the carbon price being consistently too low. Previous attempts at reform through the back-loading of allowances were unsuccessful[7]; thus, the provisions introduced by the 2030 framework may be insufficient. The EU should adopt additional measures to ensure that the price of carbon will increase, as this will act as a stimulus to reach emissions targets. For example, the ETS needs to accelerate the incorporation of all emissions from international aviation, as well as extend into sectors such as transport, currently the purview of member states. Likewise, it is important to maintain a unified carbon price across the EU; this could be done through the creation of a Common Authority with sufficient powers to maintain the carbon price within certain ranges. For sectors not covered by the ETS, the introduction of a common EU carbon tax could also help to preserve a unified carbon price[8]. Furthermore, the 27% target for renewables and energy efficiency is non-binding, as member states have refused to surrender control over their national energy mix. Therefore, countries are merely encouraged to meet these targets, and the likely result is that 'greener' member states will achieve them, while other less environmentally committed countries may not.

Member state climate and energy policies

This situation of a multi-speed Europe, whereby a group of environmentally-minded states takes the lead while others lag behind, has been a recurring problem for the EU. It goes back to the Single European Act in 1986, when climate and energy policies were established as 'shared competences'. This means that there is only so much EU institutions can do, as they cannot force reluctant member states to enact policies against their will. Due to variations in political culture and economic traditions, the environmental zeal of member states has varied considerably. Countries such as Germany, the Netherlands, as well as Scandinavian countries, have enacted many of the most ambitious environmental legislation in the world, often exceeding EU targets. For example, in 2010, the German government announced far-reaching GHG emission reduction objectives (from a 1990 baseline), including a 40% cut by 2020, 55% by 2030, 70% by 2040, and between 85-95% by 2050 [9]. Similarly, as the host of the COP21, the French government sought to set the example with its Energy Transition Law[10]. The latter includes cuts of at least 40% in GHG emissions by 2030 and 80% by 2050 (from a 1990 baseline), and an increase in renewable energies by 23% in 2020 and 32% in 2030. Likewise, French President Macron has adopted a Climate Plan, which includes reaching carbon neutrality for the French economy by 2050, as well as banning the sale of diesel and gasoline vehicles and ending fossil fuel exploitation by 2040.

By contrast, other member states have been described as 'environmental laggards'. The EU has taken into consideration the fact that certain countries may require more leeway in order to develop their economies, providing flexibility mechanisms to allow them to meet their climate targets. Nevertheless, this flexibility has sometimes been taken too far, and several member states have relied on it to avoid more robust environmental policy. For example, Poland's economy is among the most carbon and resource intensive in the entire OECD, due in part to its continued reliance on coal as a source of cheap energy. Over the last few years, Poland has been one of the largest GHG emitters per capita in the EU; in 2012, it had the highest average concentration of health-damaging particles in its air in Europe. Similarly, Estonia is the largest GHG emitter per capita in the EU, in addition to having the most carbon-intensive economy in the OECD. This is linked to its reliance on shale oil mining for cheap energy production, which has been used to support high domestic demand in winter. Over the last few years, Estonia has seen the largest relative increase of GHG emissions within the EU, especially in sectors such as electricity and heat production.

This problem of a multi-speed Europe due to shared competence is difficult to resolve. Member states have been reluctant to transfer greater powers to Brussels, especially with the rise of Eurosceptic populist movements across the region. As a result, because climate and energy policies are likely to remain shared competences for the near future, the EU needs to learn how to better utilize the tools already at its disposal[11]. Indeed, the Lisbon Treaty contains provisions that have the potential to bolster EU green legislation. Exclusive EU competences, shared competences and member state prerogatives were clarified by the Treaty's 'catalogue of competences', which contains a well-defined categorization of competence allocation in the EU legal order. Moreover, the Treaty placed environmental policy as one of the EU's core aims and top priorities[12]. Additionally, the Treaty further extended the scope of the co-decision procedure, renamed the 'ordinary legislative procedure', and mainstreamed it into almost all fields relating to the environment. Nevertheless, coordination of shared competences would be enhanced by more frequent meetings of member state environmental ministers within the EU Environment Council, as well as the establishment of more direct channels of communication between the Commission and national environmental ministries. Finally, those member states considered to be 'environmental laggards' also receive substantial funding from the EU; as an incentive for more action, the EU could apply stricter environmental criteria to the allocation of such funding in the future.

Energy Security and the internal energy market

The issue of shared competence has also hampered the EU's ability to develop an effective approach to the subject of energy security[13]. The EU imports more than half of the energy it consumes, and many member states are heavily reliant on Russia. This has made the EU vulnerable to supply disruptions; for instance, Moscow interrupted gas supplies through Ukraine in 2006, 2009 and again in 2014. In response, the EU developed an Energy Security Strategy in May 2014, and has sought to construct an integrated internal energy market. However, progress on both fronts has been slow; shared competence for energy policy has led to problems of coordination between EU institutions and member states. Likewise, despite several consecutive 'energy packages', the EU today still lacks a properly functioning and fully integrated energy market. This has had a direct impact on the EU's ability to meet its climate and energy targets. Indeed, both the EU's Energy Security Strategy and the internal energy market contain ambitious policies to increase the share of renewable energies and energy efficiency, as this contributes to reducing the EU's dependence on energy imports. Therefore, climate and energy security policies are in fact complementary.

EU institutions have been slow to recognize this connection and, although some progress has been made, contradictions remain between climate and energy security policies. For instance, the Commission has sought to enhance EU energy security by diversifying supply sources through the exploitation of new hydrocarbon resources released by the melting of ice in the Arctic. However, exploiting these new fossil fuels only accelerates global warming and the melting of Arctic ice, which allows for further exploitation of hydrocarbons, thus leading to a self-defeating cycle. In order to align its climate and energy security policies, the EU could organize a single Directorate-General (DG) within the Commission in order to bring both fields under one roof; currently, these responsibilities are divided among three different DGs with overlapping competences[14]. The same could be done within the European Parliament, where a single committee working on both energy and the environment could be created, instead of the two separate committees currently in place. Moreover, it is essential to accelerate the completion of the internal energy market by building missing infrastructure links between member states, and perhaps also establishing a unified regulator for the whole of the EU energy market. This would accelerate the integration of renewable energies within the internal energy market and contribute to spreading clean technologies across Europe. There is great potential to achieve this, given that renewables and clean technologies have experienced a dramatic fall in costs over the last few years that is set to continue, meaning they are now able to compete head-on with fossil fuels[15].

3. External environmental policy: leading the international community

Reclaiming center stage in the global climate regime

Following recent weather catastrophes, including powerful hurricanes that have swept through Texas, Florida and the Caribbean which many scientists say are directly related to global warming, Trump has faced pressure to reverse his decision over the Paris Agreement. Nevertheless, although there have been contradictory declarations over the accord, his administration is unlikely to galvanize any meaningful action on climate change, both domestically or internationally[16]. Thus, at least until the next presidential election in 2020, the US has in all likelihood vacated its former leadership role in the climate regime. If Europe succeeds in leading by example, then it will have the authority to fill the vacuum left by US withdrawal. EU leadership for the COP21 was focused more on its role as a mediator and an organizer. Europe was instrumental in creating the necessary framework that allowed for the signing of the Paris Agreement by 195 States, building bridges between developed and developing countries. Now that the US is once again withdrawing, the EU must return to center stage in the climate regime. This is important, as several large GHG emitters such as Russia, Saudi Arabia or Iran, who reluctantly signed the Paris Agreement, remain skeptical about climate policies. As large fossil fuel producing nations, they have most to lose from the global transition to clean energies. Although these countries have indicated that they will remain parties to the accord, any sign of disengagement may serve as an opportunity for them to renege on their climate pledges, which might trigger a domino effect.

In order to reclaim such a leadership role, however, Europe must first reform the procedures by which it engages in climate negotiations. While the issue of shared competence has been problematic for internal legislation, it has been even more so for external relations. It has resulted in up to three different types of actors claiming to represent the EU's position. Depending on their respective competences, this includes the Commission, the rotating Presidency of the EU Council, as well as individual member states. This resulting 'troika' has made it problematic for Europe to speak with one voice on the world stage. An internal negotiation always precedes and is often conducted at the same time as international negotiations, which has repeatedly bogged down the EU. Since countries have been reluctant to transfer greater powers to Brussels over foreign policy, the EU and its member states need to find new ways of enhancing cohesion within the climate regime. One way could be to make better use of the Lisbon Treaty's provisions for external relations, including the position of High Representative for Foreign Affairs, as well as the European External Action Service (EEAS). So far however, the EU has chosen not to involve them sufficiently during climate negotiations, perhaps to avoid overshadowing member states[17]. This is arguably a mistake. In comparison to the current 'troika system', the High Representative and the EEAS have far greater potential to provide the EU with more unity on the world stage. Speaking with a single voice is of critical importance if Europe is to succeed in reclaiming center stage in the climate regime.

Building a solid web of international climate partnerships

The international situation, however, is now very different from the last time Europe exercised such a leadership role. During the 1990s and 2000s, the EU was still the second largest GHG emitter after the US, and China was a relatively poorer country. Today, the EU is ranked third, as China has surpassed both Europe and the US as the first global emitter, and is also on track to eventually become the world's largest economy. More significantly, the EU's share of global emissions is gradually decreasing, due partly to the success of its environmental legislation, but above all because of the economic take-off of developing countries, particularly the BRICS nations. Logically, this would indicate that the EU's influence within the climate regime is set to decline and it will not be able to exercise a leadership role on its own. As a result, it is essential for the EU to establish a strong collaboration with China in international climate negotiations; this partnership should serve as the new backbone of the Paris Agreement. If they succeed in working together as the first and third largest global GHG emitters, the EU and China should be able to counteract disengagement from the US (the 2nd global emitter). Chinese President Xi Jinping has reaffirmed his determination to implement China's commitments under the Paris Agreement and safeguard the climate regime. China has strong incentives to transition towards a greener future, as the country is facing a severe ecological crisis due to uncontrolled economic development[18]. Moreover, Beijing sees Trump's semi-isolationism as an opportunity for China to step into a leadership position and heighten its influence on the world stage, legitimizing its concept of 'regime neutrality'[19].

Therefore, there is great potential for enhancing the partnership between the EU and China within the climate regime. Indeed, they worked closely together during the latest COPs, and even issued a joint declaration to support the Paris Agreement following Trump's announcement of withdrawal. Since the EU is China's first trading partner and China is Europe's second trading partner, they have already established a close working relationship on many issues. Since 2003, China and the EU have been involved in a Strategic Agenda for Cooperation, which involves annual Summits that cover a wide range of topics from trade to security. This has provided a basis for the development of a variety of frameworks for cooperation specifically on 'green issues', including the Climate Change Partnership since 2005, the Environment Policy Dialogue held at Ministerial level, as well as the EU-China Energy Cooperation Roadmap signed in 2016. While impressive, these different platforms have focused more on dialogue and information sharing, rather than concrete policy issues. Thus, it is important to reform the mechanisms for EU-China cooperation so that they deliver tangible policy results that are related to the COP process. Nevertheless, while it is essential for the EU and China to enhance their partnership to safeguard the Paris Agreement, Europe cannot ignore Beijing's poor human rights record. This would be in contradiction with core European democratic values. As a result, the key for the EU is to strike a delicate balance by reinforcing cooperation with China, while not hesitating to criticize the Chinese Communist Party's human rights abuses and authoritarian governance, when appropriate.

Because climate change is a genuinely global issue, dual EU-Chinese leadership, while essential, will not be sufficient on its own. All nations need to participate, otherwise there is the danger of free-riding, whereby one country or group of countries benefit from the efforts of all the others while not making adequate efforts themselves. The EU should rely on its experience as a successful mediator in building bridges between developed and developing nations to construct a solid web of international climate partnerships to ensure a genuinely global level of commitment to the Paris Agreement. Firstly, most developed countries continue to provide extensive and legally binding sets of commitments, thus they still have a key role to play in the climate regime. As a result, building strong climate partnerships with prosperous countries such as Canada and Japan remains very important. The EU has recently signed a Free Trade Agreement (FTA) with Canada in October 2016, known as the 'Comprehensive Economic and Trade Agreement' (CETA); likewise, the EU has also recently concluded negotiations for another FTA with Japan in July 2017. These FTAs contain several clauses on trade and investment in environmental goods and services, including tariff liberalization for energy efficient and renewable energy products, which can form the basis for more sustained cooperation on climate policy. Nonetheless, several analysts have criticized these environmental clauses for lacking meaningful enforcement mechanisms, and point out that they risk being bypassed due to the creation of a parallel, privatized justice system known as the Investment Court System. Such issues will need to be more fully addressed as these FTAs are implemented in the years to come[20].

Ensuring global commitment and a strong legal framework for the climate regime

Perhaps the greatest change in the climate regime over the last decade has been the rise to prominence of developing countries. The Kyoto Protocol imposed binding targets only on developed countries, with developing countries being protected under the principle of 'common but differentiated responsibilities'[21]. However, due to rapid economic growth, developing countries have now become major GHG emitters, thus they must also be integrated into the climate regime. The EU has been instrumental in finding compromise solutions considered as fair by developing countries to convince them to ratify the Paris Agreement. This is partly because the EU has been the world's largest donor of aid for several decades, allowing it to build a strong network of partnerships with developing countries, mostly in the African, Caribbean and Pacific regions (ACP). Moreover, the EU has also been the global leader regarding climate finance for many years, providing extensive monetary and technical assistance, including technology transfers, to help developing countries mitigate their emissions and adapt to global warming (poor countries are the most vulnerable to its effects). The EU participates in a multitude of international frameworks for climate finance such as the Green Climate Fund, and often relies on financial and technical assistance as an incentive to convince developing countries to sign onto climate pledges. Indeed, the EU's role as the global leader in climate finance will become especially important following US withdrawal from the Paris Agreement [22].

The same applies to the emerging BRICS nations. India, for example, has enjoyed several decades of strong growth and is now the world's fourth largest GHG emitter (after China, the US and the EU). Indian Prime Minister Narendra Modi confirmed his unwavering support for the Paris Agreement following Trump's announcement of withdrawal. India, which has a long tradition of environmental activism, seeks to play a leading role in the climate regime to enhance its influence on the world stage. Following the establishment of a strategic partnership in 2004, the EU has reinforced its ties with India through annual Summits that cover a broad range of topics, including environmental issues. This comprises the Initiative on Clean Development and Climate Change, the EU-India Environment Forum, as well as the Clean Energy and Climate Partnership agreed to during the 2016 Summit. Unlike the Environment Policy Dialogue with China, however, there is no institutionalized framework for bilateral EU-Indian cooperation at the Ministerial level on climate and environmental issues. Thus, the EU and India should establish formal regular meetings between the European Commissioner for Climate Action and his Indian counterpart to consolidate their partnership within the climate regime. Cooperation between India and Europe is arguably made easier by the fact that they share common democratic values. Thus, as India's economy continues to grow, the EU-Indian climate partnership will likely become key to the future evolution of the global climate regime.

Europe should also seek to find ways to reinforce the legal architecture of the climate regime. While ensuring a global level of commitment from both developed and developing countries is essential, the Paris Agreement, like many environmental accords, is not legally binding. It represents a "procedurally, rather than substantively binding agreement"[23]. This is unsurprising, as the climate regime has always suffered from weak legal enforcement mechanisms. Therefore, French President Macron's initiative in the summer 2017 to propose a new Global Pact for the Environment is a step in the right direction. The purpose of the Pact is to provide "a global legal text bringing together fundamental principles of environmental law", which aims to become the "cornerstone of international environmental law" [24]. The Global Pact would become a legally binding treaty that could be invoked within national jurisdictions to hold states to account on environmental issues. The EU needs to ensure that member states ratify this Pact rapidly to enhance its credentials as a global environmental leader. Moreover, Europe should rely on its extensive network of climate partnerships with both developed and developing countries to build a broad level of international support for the Global Pact. This will help to ensure its ratification when submitted to the UN General Assembly.

In conclusion, Europe can and should become the guardian of the Paris Agreement on climate change. Following US disengagement, there is a leadership vacuum that needs to be filled. The EU and its member states have the potential to lead by example, as they are in the process of enacting some of the most far-reaching environmental legislation in the world. However, problems of coordination between member states and EU institutions under shared competence, as well as institutional competition and occasional contradictions between climate and energy security policies, will need to be addressed. The EU has begun to position itself at the heart of the global climate regime through an extended web of partnerships with both developed and developing countries around the world. Nonetheless, Europe will need to enhance cohesion in climate negotiations by speaking with a single voice on the world stage, as well as work on reinforcing the legal architecture of the climate regime. There is great potential for the EU to strengthen both its internal and external climate actions, as opinion surveys indicate consistently high levels of popular support on this issue across the EU[25] .

Overall, Europe needs the climate regime as much as the climate regime needs Europe. Indeed, the EU is currently suffering from internal divisions with the rise of populist Eurosceptic movements. Climate change represents a salient issue with the potential to enhance European unity, since most member states agree that action should be taken. Moreover, if the EU succeeds in enacting ambitious environmental legislation, this will attract green investments and international entrepreneurs, helping to consolidate the economic recovery. Likewise, climate diplomacy has also provided EU external relations with a palpable success. Regardless of weaknesses in other areas, climate negotiations represent an opportunity for the EU to bolster its presence on the global stage. Conversely, the climate regime needs the EU because otherwise, following US disengagement, China risks filling-in the vacuum on its own and becoming the main power. If an authoritarian government comes to dominate the global climate regime, this might impact its legitimacy in the long run. Thus, EU leadership is necessary to balance China's power and infuse democratic values into the climate regime. This is especially true since the EU, due to its very nature, is ideally positioned to contribute. Climate negotiations do not require any sort of hard military power, but rather subtle diplomatic skills and 'soft power'. As an archetypical normative power, the EU can successfully rely on tools such as multilateral diplomacy to shape the international climate agenda and become the guardian of the Paris Agreement.