cbd-ts-66-en

Part II: The Regulatory Framework for Climate-related Geoengineering Relevant to the Convention on Biological Diversity
2.4 PRECAUTIONARY PRINCIPLE OR APPROACH
There is no uniform formulation or usage for the precautionary principle or approach,48 and its legal status in
customary international law has not yet been clearly established,49, 50, 51 although it has been invoked several times.52
Under the Convention on Biological Diversity, the precautionary approach is introduced in the preamble, where
it is noted that “where there is a threat of significant reduction or loss of biological diversity, lack of full scientific
certainty should not be used as a reason for postponing measures to avoid or minimize such a threat”. The decisions
of the Conference of the Parties to the Convention have frequently been based on and stressed the importance of
the precautionary approach,53 including in decision X/33, which addresses geoengineering (see section 3.1 below
on CBD). Under the London Protocol, article 3.1 requires the application of the precautionary approach.
Another legal formulation in the operative part of a treaty text with near universal application is Article 3(3) of
the United Nations Framework Convention on Climate Change (UNFCCC).54 Almost all States have ratified the
UNFCCC,55 including the US.56 While this renders the question of the precautionary principle/approach’s legal
status in customary law less relevant, the precise consequences remain unclear.
On the one hand, while all proponents of geoengineering stress that it is no substitute for reducing emissions, they
would argue that it would contribute to fighting climate change:57 extracting carbon dioxide from the atmosphere
reduces greenhouse gases, and solar radiation management has the potential to limit temperature increases. On
this basis, it might be argued that lack of full scientific certainty should not be used as a reason for postponing
geoengineering, provided that there are threats of serious or irreversible damage. Geoengineering proponents
would argue that such threats exist, in view of the slow progress in reducing global emissions at source and the
short time remaining during which emission trends need to be reversed (peak).
On the other hand, faced with this same scenario, it may be argued that the precautionary approach would imply
following the less risky action of implementing emission reductions. In fact, at the time it was drafted, Article
3(3) of UNFCCC was generally viewed as having the intention of postponing mitigation measures by referring to
scientific uncertainty about climate change. In this context, an interpretation in support of geoengineering would
48 Cf. Principle 15 of the Rio Declaration; Article 3.3 of UNFCCC; Article 3 of the London Protocol; CBD Preamble; Birnie et al. (2009),
p. 160.
49 Cf. Virgoe, J. (2009), p. 111; UK House of Commons Science and Technology Committee (2010), paras. 85–86. Güssow et al. (2009),
p. 15, acknowledge a “considerable degree of unclarity (sic) as to its normative content and validity”, but apply Principle 15 of the Rio
Declaration without further analysis as to legal status.
50 Cf. Article 11 of the 1982 World Charter for Nature and article 6 of the 2000 Earth Charter.
51 See generally Birnie et al. (2009), p. 152 ff.; UK House of Commons Science and Technology Committee (2010), para. 86. On the basis
of the heading “principles” in Article 3.3 of UNFCCC, the present study uses the term “precautionary principle” without prejudice to
this debate.
52 In its judgment on the Pulp mills on the river Uruguay case, the ICJ considered that a precautionary approach may be relevant in
the interpretation and application of the provisions the treaty in question, but it rejected Argentina’s argument that it operates as
a reversal of the burden of proof: cf. Memorial of Argentina of 15 January 2007, paras. 3.194-3.197 and 5.15. and the judgment,
para. 164. (All documents available at www.icj-cij.org.) See also dissenting opinions of Judges Weeramantry and Palmer in the ICJ
cases Nuclear Tests II, paras. 342 and 412; dissenting opinion of Judge Weeramantry in the Nuclear Weapons opinion, para. II.10.e; see
also WTO Appellate Body, EC Measures Concerning Meat and Meat Products (Hormones), paras. 16 and 120–125; ITLOS Case No.17,
“Responsibilities and obligations of States sponsoring persons and entities with respect to activities in the Area (Request for Advisory
Opinion submitted to the Seabed Disputes Chamber)”, http://www.itlos.org; separate opinion of Judge Wolfrum in the ITLOS Case
No. 10, The MOX Plant Case (Ireland v. United Kingdom), Provisional Measures (www.itlos.org); see also Marr (2000).
53 See for instance CBD decisions IV/10 para. 1; V/3 para. 5; VI/7 annex I, paras. 24 and 31; VI/26 annex, para. 1(e); VII/5 annex I,
appendix 3, para. 2; VII/11 principle 6, guideline 6.2; VII/14, paras. 54 and 75.
54 United Nations Framework Convention on Climate Change, of 9 May 1992, 31 ILM 849 (1992), in force 1994.
55 Currently 194 Parties, http://unfccc.int/parties_and_observers/parties/items/2352.php.
56 The US is one of the major emitters and potential geoengineering States but is not Party to the Kyoto Protocol.
57 All proponents of geoengineering acknowledge and stress that it does not reduce anthropogenic CO 2 emissions levels.
119