Obligations of conduct in the international law on climate change: A defence

• Date: 01 July 2018
• DOI: http://doi.org/10.1111/reel.12237
• Published date: 01 July 2018

ORIGINAL ARTICLE

Obligations of conduct in the international law on climate

change: A defence

Benoit Mayer

Correspondence

Email: bmayer@cuhk.edu.hk An obligation of conduct is an obligation to make an honest endeavour, notwithstand-

ing the outcome. From the no-harm principle to the United Nations Framework Con-

vention on Climate Change and the Paris Agreement, obligations of conduct play a

central role in the international law on climate change mitigation. They are not simply

the result of political tradeoffs with reluctant States, but they address real concerns

with the unpredictable costs of implementing specific mitigation targets over a decade

or more. This article retraces the origins of obligations of conduct in the French law of

obligations and its reception in international law. It then highlights the prominence of

such obligations in the international law on climate change mitigation. Based on this

analysis, it contends that obligations of conduct are an effective tool to promote ambi-

tion and participation to international efforts on climate change mitigation.

1

|

INTRODUCTION

Any obligation belongsto one of two types. The obligations of the first

type, called ‘obligations of result’, require the realization of a specified

outcome. By contrast, the obligationsof the second type, called ‘obliga-

tions of conduct’, requirean endeavour towards a goal or an outcome.

A classic exampleof an obligation of conduct is the obligation of a med-

ical doctor towards her patient. Imposing onher an obligation of result

would be unreasonable:she cannot be held liable whenever she fails to

cure a patient. Nevertheless, this doctor is expected to endeavour to

treat her patientto the best of her abilities. The breach of this obligation

of conduct may engageher professional, civil or even criminalliability.

This distinction, drawn from civil law traditions, appears as a useful

tool to interpret thesubstantial obligations of States with regard to cli-

mate change mitigation, in particular –but not only –under the Paris

Agreement.Qualifying the nature of an obligation as either an obligation

of result or anobligation of conduct is essential to determining the con-

ditions and processes to assess compliance. An obligationof result is to

be found in the Kyoto Protocol –the obligation foreach Annex I party

to ‘ensure’that its aggregate greenhouse gas (GHG) emissions do not

exceed an assignedamount.

1

By contrast,as will be shown in this article,

the general international law obligation of States not to causesignificant

transboundary harm (the no-harm principle) is more convincingly con-

strued as an obligation of conduct. Consistently, the Paris Agreement

turned, in the second sentence of Article 4(2), to what clearly qualifies

as an obligationof conduct –an obligation for countryparties to ‘pursue

domestic mitigation measures, with the aim of achieving the objectives

of’their successive nationallydetermined contributions(NDCs).

2

Article 4(2), second sentence, constitutes arguably the centre of

gravity of the Paris Agreement: it inserts NDCs within the system of

obligations created by the treaty.

3

Yet, early commentaries on the

Paris Agreement draw a rather confusing image. For instance, while

Daniel Bodansky suggests that this provision ‘was formulated as an

“aim”rather than as a legal obligation’,

4

Lavanya Rajamani sees there

the expression of ‘binding obligations of conduct coupled with a good

faith expectation of results’.

5

Rajamani, however, does not further

----------------------------------------------------------------------------------------------------------------------------------------------------------------------

©2018 John Wiley & Sons Ltd, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA.

1

Kyoto Protocol to the United Nations Framework Convention on Climate Change (adopted

11 December 1997, entered into force 16 February 2005) 2303 UNTS 162 art 3(1).

2

Paris Agreement (adopted 12 December 2015, entered into force 4 November 2016) 55

ILM 740 art 4(2).

3

By contrast, ibid art 3, first sentence, provides a broader but vaguer commitment of the

Parties to ‘undertake and communicate ambitious efforts’on climate change mitigation,

adaptation, support and transparency.

4

D Bodansky, ‘The Paris Climate Change Agreement: A New Hope?’(2017) 110 American

Journal of International Law 288, 295. See also C Bakker, ‘The Paris Agreement on Climate

Change: Balancing “Legal Force”and “Geographical Scope”’ (2015) 15 Italian Yearbook of

International Law 299, 307; J Brunn

ee, ‘The Rule of International (Environmental) Law and

Complex Problems’(6 December 2017) <https://ssrn.com/abstract=3080458>.

5

L Rajamani, ‘The 2015 Paris Agreement: Interplay between Hard, Soft and Non-obligations’

(2016) 28 Journal of Environmental Law 337, 354. See also, e.g., L Rajamani and J Brunn

ee,

‘The Legality of Downgrading Nationally Determined Contributions under the Paris Agree-

ment: Lessons from the US Disengagement’(2017) Journal of Environmental Law 542.

DOI: 10.1111/reel.12237

130

|

wileyonlinelibrary.com/journal/reel RECIEL. 2018;27:130–140.