Perhaps the most widely debated event in global climate policy since the Paris Agreement’s adoption in 2015 was the United States’ decision in June 2017 to withdraw from the treaty, pending possible re-engagement under different terms.

When the announcement was on the cards, some commentators argued that the US would be ‘better out than in’, not least because US absence from talks on implementing the Agreement would reduce its ability to scuttle progress from the inside. Others argued that the net effect of the decision was just as likely to undermine global cooperation as to stimulate action in other countries.

At the annual UN climate talks in November, most parties to the Agreement (now numbering more than 170 countries) put on a brave face, although developing countries added the US decision to their list of reasons for doubting the willingness of developed countries to adhere to the Agreement. Meanwhile, the US sent mixed messages about its stance: career diplomats on the US negotiating team were keeping a low and relatively non-obstructive profile; a White House adviser sat on a panel extolling the virtues of coal; and US states, cities and businesses were showcasing their ongoing commitment to the Agreement.

In a situation this murky, how can we get a clearer picture of what the US decision means for global climate policy?     

How far from Kyoto to Paris?

Until the dust settles, it remains to be seen what the longer-term impact of the US decision will be. In the meantime, one promising way of assessing the implications of the decision to withdraw is to compare it with previous experience, rather than with with a counterfactual (and inevitably speculative) decision to stay in. In a new article in the peer-reviewed journal Climate Policy we do just that, by comparing and contrasting US non-participation in the Kyoto Protocol and the Paris Agreement.

The Clinton Administration signed the Protocol in 1998, but in 2001 the George W. Bush Administration announced the US did not intend to ratify it. The Kyoto Protocol did eventually enter into force in 2005, but US non-participation was widely seen as damaging for the Protocol’s effectiveness and legitimacy.

We focus on four key areas that may shape the effects of US treaty decisions for international climate policy:

(i) Global momentum on climate change mitigation

We find that increasing global momentum on climate mitigation since 1997 means that US withdrawal from the Paris Agreement is potentially less damaging than its non-participation in the Kyoto Protocol. But despite the declining US share of global emissions, greater urgency for deep decarbonisation means that the non-participation of a major player such as the US remains problematic for achieving the Paris Agreement’s goals.

(ii) Opportunities to form rival initiatives

US damage to the Kyoto Protocol framework resulted not only from its non-participation, but also from its creation of rival forums for international collaboration on climate policy, notably the Asia-Pacific Partnership on Clean Development and Climate (APP). While the APP ultimately withered on the vine, its presence was enough to cast a shadow over the UNFCCC’s legitimacy for a number of years.

Since our article went to press, news has emerged that the US plans to form a new international alliance to promote burning coal. It is likely that heavy coal users such as India, China, and Australia will be invited to join. With this move, the Trump administration is clearly taking a leaf from the G. W. Bush administration’s climate policy strategy. But in our view it is unlikely that this will prove as destabilising for global cooperation as the APP. There is now increasing global momentum to phase out coal, as reflected in the rival Powering Past Coal Alliance, which numbers around 26 countries (albeit none of the world’s biggest coal users so far). In a related new article in Climate Policy, Detlef Sprinz and colleagues find that climate ‘clubs’ set up alongside the UNFCCC to accelerate mitigation could function even without the US being on board, although their coverage of global emissions would be modest and some potential members could be dissuaded by US non-participation. Ongoing dysfunction within the US Department of State may also limit the coal alliance’s prospects.

(iii) Timing and circumstances of the US decision to exit

Because the US was not already a party to the Kyoto Protocol, President Bush’s decision not to ratify had immediate effect. But under the provisions of the Paris Agreement, the earliest that the US can formally withdraw is 4 November 2020, which happens to be the day after the next US Presidential election. Given this delay, it is uncertain that withdrawal will ultimately go ahead. Despite the Trump administration’s continuing reluctance to take domestic action on climate change, the time lag for formal withdrawal from the Paris Agreement tends to diminishes the short-term signalling effects of the US decision.

(iv) Influence of treaty design on incentives to participate and comply

Differences in the design of the Kyoto Protocol and Paris Agreement suggest that US non-participation is more likely to prompt reluctant countries to stay within the Paris framework but reduce levels of ambition and compliance, rather than to exit the Agreement altogether.

A key reason for this is that the Paris Agreement’s ‘Nationally Determined Contribution’ approach gives countries considerable flexibility in how they frame their contributions to mitigation. This makes it less likely that they will find themselves bound to targets that lack domestic ownership and support. While parties are bound to prepare, communicate and maintain successive NDCs, they are not legally bound to achieve them. In contrast, parties to the Kyoto Protocol were bound to meet their targets. Canada judged in 2011 that it was preferable to withdraw from the Protocol altogether, rather than risk non-compliance when it became clear that it would overshoot its Kyoto target.

Putting it all together

Our comparison highlights important ways in which the negative effects of US withdrawal may be less severe under the Paris Agreement than under the Kyoto Protocol. This finding is complemented by another new article in Climate Policy by Johannes Urpelainen and Thijs Van der Graaf. Assessing the US decision from a broader international relations perspective, the authors argue that ‘the Paris Agreement has introduced a new logic of domestically driven climate policies’.

Even so, the negative impacts of US withdrawal from the Agreement could still be significant, so it is hard to be confident that US withdrawal will be better for climate policy than if it had remained. Indeed, our analysis suggests that even now, some of the risks demonstrated by the US withdrawal from the Kyoto Protocol will remain major concerns for the future of the Paris Agreement. Crucially, US non-participation may demotivate other countries at a time when mutual assurance and greater ambition remain critical for a safe future climate system.

This article was originally posted on the Climate Strategies blog, and can be found here: https://climatestrategies.wordpress.com/2018/01/04/assessing-the-us-retreat-from-the-paris-agreement-backtracking-to-kyoto/