5.1 International Law
5.1.4 Cloud brightening from ships
Cloud brightening, also referred to as cloud-albedo enhancement or cloud seeding, describes a geoengineering technique by which clouds are increased and whitened over parts of the ocean and therefore reflect more short-wave solar radiation back to space.206 The idea is to increase cloud-condensation nuclei per unit volume in low-level marine clouds, which scatter and reflect more of the incident light.207 In practice, a “suitable hydrophilic powder”208 would be released from a conventional ocean-going vessel into the troposphere, particularly over ocean areas.
Generating fine particles of sea-salt derived from ocean water is the most prominently
discussed technique,209 although other proposals for cloud brightening could be developed.210
5.1.4.1 Ozone Convention and Montreal Protocol
The ozone regime, including its general obligation under Article 2(1) of the Ozone Convention, could apply to cloud brightening, provided that sea-salt particles are considered as ozone modifying or likely to modify the ozone layer in accordance with the provisions of the Ozone Convention.
As discussed in the section on aerosol injection into the stratosphere, paragraph 4 of Annex I to the Ozone Convention contains a list of substances which “are thought to” have the potential to modify the ozone layer. Paragraph 4 (e) of Annex I lists, among others, “hydrogen substances”, including water, which “plays a vital role in both tropospheric and stratospheric
photochemistry.211 Cloud brightening would release sea-water vapor, which would increase the concentration in the lower atmosphere of very small sea-salt particles as cloud condensation nuclei212 (also referred to as cloud seeds). While such cloud nuclei do not appear to be potentially ozone-depleting substances, water vapor, which is used as a “vehicle” for this technique, potentially could be ozone depleting.213
Additionally, Article 2 (1) of the Ozone Convention requires that the introduction of cloud nuclei results in “deleterious effects” (see above on aerosol induction).214 Cloud brightening is
206 Williamson et al (2012) 8; See also Royal Society (2009) 26 and GAO (2011) 35.
207 Williamson et al (2012) 26 and 51. See also Royal Society (2009) 27.
208 Royal Society (2009) 27.
209 Royal Society (2009) 27. See also BPC (2011) 10.
210 See House of Commons (2010) Ev 33.
211 Proelß et al. (2011) 32, also address water vapor in their consideration of the Ozone Convention, while the version of the study by Rickels et al. (2011) does not address this issue in this context.
212 Rickels et al. (2011) 42.
213 Zedalis (2010) 22, concludes that “geoengineering strategies designed to generate previously non-existent, or stimulate the futher development of naturally present cloud nuclei through pumping water vapor or other hydrogen sources into the troposphere would fall within what the Convention considers an activity modifying or likely to modify the ozone layer”.
214 Zedalis (2010) 22 emphasizes this requirement.
expected to result in strong regional or local atmospheric and oceanic perturbations.215 While the overall effects are difficult to assess, there could be strong local effects such as local cooling, which may potentially cause negative effects on biodiversity and ecosystems.216 Therefore, it is possible that the impacts of cloud brightening could cause deleterious effects within the scope of the Ozone Convention. If such deleterious effects occur, the obligations of the Ozone
Convention apply to the use of water vapor in cloud brightening techniques. However, the actual content of the obligations under the Ozone Convention are weak and, as in the case of aerosol injection, would not prohibit cloud brightening as such (see section on aerosols). As for the Montreal Protocol, water vapor is not among the substances regulated by it.
5.1.4.2 UNCLOS
The release of particlesfrom ocean-going vessels217 is generally governed by the provisions of UNCLOS. UNCLOS contains provisions regulating for each “maritime zone” the navigation of the releasing vessel and activities to be undertaken in this zone. In addition, UNCLOS contains provisions regarding the protection of the marine environment, which apply to the marine environment as a whole, including the high seas.
Cloud brightening activities in the territorial sea of a state are subject to the laws and
regulations of that state in accordance with Article 2 (1) UNCLOS. A ship, which is intended to release particles for cloud seeding in the territorial sea of a state other than its flag state, could be allowed to navigate in this maritime zone by the “right of innocent passage” in accordance with Article 17 UNCLOS. The right of innocent passage only covers “continuous and
expeditious” passage in accordance with Article 18 (2) UNCLOS, with stops and anchoring generally only taking place as required by “ordinary navigation”. Navigation of ships for cloud brightening activities may not fulfill this condition if it includes stops for the release of sea-water vapor.218 In addition, a passage is not “innocent” according to UNCLOS if it constitutes an
“act of willful and serious pollution” contrary to the provisions of UNCLOS, or “research or survey activities”, or an “activity not having a direct bearing on passage”.219 While the release of water vapor is unlikely to cause serious pollution, cloud seeding research would be excluded.
The deployment of cloud brightening activities would constitute an activity not having a direct bearing on passage, and therefore also exempt the vessel from the right of innocent passage.220 Cloud seeding in the EEZ is subject to the provisions of Part V of UNCLOS. The provisions of this part define which activities in this zone are subject to the jurisdiction of coastal states, which freedom other states enjoy, and which procedure applies for activities not covered by the former or the latter set of rules.
Under Article 56 (1) (b) (ii), “marine scientific research” is one of the activities in the exclusive economic zone which is to the jurisdiction of the coastal state. While UNCLOS does not define
215 See with further references: Williamson et al (2012) 51. See also GAO (2011) 36.
216 Williamson et al (2012) 51.
217 Assuming that such vessels are considered “ships” for the purposes of UNCLOS. See Proelß et al. (2011), p. 33, for a detailed explanation, why vessels are to be considered ships in this case. Rickels et al. (2011), do not include the same detailed discussion.
218 Rickels et al. (2011), p. 92.
219 Article 19 (1)-(2)(h),(j) and (l).
220 With the same result, but focusing on cloud seeding as research, see Rickels et al. (2011), p. 92.
marine scientific research, it has been argued that cloud brightening activities would not qualify, because the main activity, the release of particles into the stratosphere, takes place in the air, not the sea.221 As the particles released will eventually be washed down into the marine environment, a similar argument could be made as in the case of aerosols under the LC/LP (see section 5.1.3). In addition, the subject of cloud brightening research is not the marine
environment, even though the activities might have implications for it. For this reason research regarding cloud brightening does not constitute marine scientific research and is therefore not subject to the jurisdiction of the coastal state according to Article 56 (1) (b) (ii).222
Furthermore, cloud brightening activities could be subject to sovereign rights of the coastal state with regard to activities for the economic exploitation and exploration of the EEZ in Article 56 (1) (a) UNCLOS. Cloud brightening activities, however, are arguably not intended for economic exploitation or exploration of the EEZ.
Furthermore, cloud brightening does not appear to be covered by the freedom of navigation which states enjoy in the EEZ of another state in accordance with Article 58 (1) and Article 87 (1)(a) UNCLOS. Cloud brightening activities arguably are not a “passage”, and also not
“navigation” or “uses of the sea related to” navigation.223 Therefore, only the navigation of a ship for cloud brightening into the EEZ of another state could be covered by the freedom of navigation, not the cloud brightening activity as such.
On this basis, cloud brightening activities in the EEZ are neither subject to the jurisdiction of the coastal state, nor covered by the rights of other states under Arcticle 58 UNCLOS.
Accordingly, cloud brightening activities would be covered by Article 59 UNCLOS which requires that conflicts have to be resolved on the basis of equity and in the light of all the relevant circumstances, taking into account the respective importance of the interests involved to the parties as well as to the international community as a whole. Strictly speaking, cloud brightening would have to be assessed on a case by case basis. Cloud brightening could be permitted based on, for instance, an argument could be made that geoengineering activities would be conducted in the interest of the international community.224
Cloud brightening activities taking place at the high seas would generally be covered by the freedoms of the high seas, which are not limited to those expressly listed in Article 87 (1)
UNCLOS. However, these freedoms are subject to “the conditions laid down by [UNCLOS] and by other rules of international law”.
For example, cloud seeding activities in any marine area (except internal waters) would
arguably have to be in conformity with the provisions of UNCLOS, in particular those in Part VII on the protection of the marine environment.225 According to Article 192 UNCLOS states have a general duty to protect and preserve the marine environment and to take all measures
necessary in order to prevent, reduce and control marine pollution from any source, including by dumping (Articles 1, 194, 210 UNCLOS).
221 Rickels et al. (2011), p. 92.
222 Same assessment by Rickels et al. (2011), p. 92.
223 For a similar assessment see Rickels et al. (2011) 93.
224 See Proelß et al. (2011), p. 37. Rickels et al. (2011), discuss the issue in less detail, Rickels et al. (2011), p. 93.
225 Zedalis (2010), p. 28, and Rickels et al. (2011), p. 93, also point out the relevance of these rules for cloud brightening.
“Pollution of the marine environment” is defined in Article 1(4) UNCLOS as the introduction by man, directly or indirectly, of substances into the marine environment that are likely to cause deleterious effects to living resources, human health or marine activities and uses. For cloud brightening activities to constitute such an introduction, either the air above a marine area would have to be part of the marine environment or washing down of cloud nuclei into the sea at some point would still have to qualify as introduction. Above it was argued that the
introduction of substances into the stratosphere would not qualify as disposal into the sea, even if they are washed down eventually. Whether the same line of arguments can be applied to the introduction of substances into the marine environment under UNCLOS needs to be further assessed for each individual case. The further requirement for “pollution”, that this
introduction would likely result in deleterious effects, cannot generally be ruled out.226 To the extent that cloud brightening would constitute marine pollution according to Article 192 UNCLOS, the relevant provisions of the Conventions Part VII apply (see the section on ocean liming for further analysis).
5.1.4.3 London Convention and London Protocol
The assessment of the provisions of the LC and LP in the context of the injection of H2S and SO2
into the stratosphere applies to cloud brightening. Dumping explicitly includes the disposal of matter from ships, water vapor as “material and substance of any kind, form or description”227 constitutes "wastes or other matter", and the release of particles for cloud brightening would be deliberate. As with the injection of H2S and SO2 into the stratosphere, it is questionable whether the particles are disposed into the sea. As argued above, such particles may only be washed down into the sea at some later point, transformed by chemical reaction into other substances.
An interpretation that would consider all activities which release substances and are eventually washed into the sea as dumping, would widen the scope of the LC and LP far beyond its textual scope.
If a different argumentation is followed and cloud brightening is considered dumping under the LC and LP, the exception in LC Article 3(1)(b)(2) and LP Article 1(4.2.2) could apply. As discussed above regarding the injection of H2S and SO2 into the stratosphere, whether cloud brightening activities would be exempt from the definition of dumping depends on whether they are considered contrary to the aims of the LC or the LP.
Furthermore, even if cloud brightening activities were to constitute dumping, the exception in Article 4 (1.1) LP and paragraph 1.6 of its Annex would exempt this activity from the general prohibition of dumping and subject it to the requirement of a permit only (Article 4 (1.2)).
Thus, sea-water vapor, “may be considered for dumping” under Annex I, paragraph 1 (6) LP as it constitutes “organic material of natural origin”.
5.1.4.4 Nature and ecosystem protection
The introduction of sea-water particles into the troposphere for cloud brightening raises similar question as the introduction of H2S and SO2 into the stratosphere. As for aerosol injection, examples for relevant provisions are:
• the obligation to protect the habitat of migratory species listed in Annex I to the CMS (Article 3 (4) CMS);
226 Convention on Biological Diversity (2012), p. 48.
227 According to Article 3 (4) LC and Article 1 (8) LP.
• the obligation to promote the protection of wetlands according to Article 4 (1) of the Ramsar Convention
• the obligation to take measures to protect and conserve world heritage sites according to Article 5 of the World Heritage Convention.
In addition, the rules and guidance established by the CBD COP could be relevant. Although they are not binding, they are likely to influence and potentially de facto restrict the actions of parties (see section on CBD Decision X/33). Relevant guidance include the Jakarta Mandate on costal and marine biodiversity (Decision II/10), the protection of genetic resources in areas beyond national jurisdiction (decision VIII/21) and the establishment of marine protected areas (decision VIII/24).
The effectiveness of some of these instruments is limited due to small number of parties, or by qualifying clauses softening their specific content. Therefore there appear to be no specific obligations which would be breached by cloud brightening, although this could depend on the scale of deployment.
5.1.4.5 Conclusion
Against this background, it is difficult to assess in abstract whether and to what extent cloud brightening would be permitted. The Ozone Convention, even though potentially applicable, does not impose practically significant restrictions. UNCLOS provides the most pertinent rules, but for activities in the EEZ refers to the resolution of conflicts in each individual case. As for the high seas, it is arguable but not clear that cloud brightening would fall under the UNCLOS provisions against marine pollution. The LP does not prohibit cloud brightening as long as sea water vapor is used and does not constitute dumping.