While all existing definitions have strengths and weaknesses, the definition developed by an expert group in the impact study for the CBD appears to the most convincing to date:36
A deliberate intervention in the planetary environment of a nature and scale intended to counteract anthropogenic climate change and/or its impacts.
The definition is concise while including all the essential elements discussed above. It is workable in the sense that guides the necessary further refinements regarding thresholds, measuring etc. However, the definition has weaknesses that would make it insufficient for a regulatory purpose if applied by itself (see further below in this section).
Alternatively, applying a highly broad, inclusive, and multi-purposed definition, one that attempts to cover all techniques that have been considered geoengineering and most of the
35 Parson and Keith (2013) 1279.
36 Williamson et al (2012) 8. On the wording of the CBD’s 2010 geoengineering decision see Bodle (2010) 315-316.
discussed intentions, but that is not appropriate for narrower regulatory or governance purposes, geoengineering could be preliminarily defined as:
Activities designed and undertaken with the purpose of producing environmental change on a regional or global scale, primarily for counteracting anthropogenic climate change or reducing its warming impacts, through, inter alia, removal of greenhouse gases from the atmosphere or reducing solar insolation.
The selection of the activity, activity and intervention respectively, are both relatively neutral subjects without significant subtexts or connotations. Activity carries somewhat greater impartiality, as intervention may begin to implicate purpose and intent, and perhaps greater definitional clarity can be achieved by separating out these elements.
On the other hand, the elements are intimately connected. The CBD impact study’s definition captures and uses this connection advantageously, linking the description of the activity with intent, purpose, and scale. As discussed, purpose and intent, while serving to identify the deliberate and man-made nature of the environmental change, fail to stand alone in the absence of scale. On the other hand, scale without purpose or specific intent leaves open the possibility of unintended climate impacts, primarily from anthropogenic warming.
As noted, it is not entirely clear why, applying a strict interpretation, both purpose and intent are needed in a definition. One conceivable rationale is that deliberation signifies the intent of the actor executing the geoengineering method, whereas purpose denotes the primary
application of the technique in use. Including both could eliminate a degree of concern over discerning both feasibility of methods and subjective intent. Thus, where applied methods are unsuccessful but used in a manner intended for geoengineering change, or where a technology designed for geoengineering is deployed for an alternative purpose or unintentionally, both scenarios with potential risks and adverse impacts, this two-fold angle captures both cases.
Along this line of thought, specifying activities “designed and undertaken with the purpose of producing environmental change” in the above definition seeks to capture both the intent of the actor and the methodological design. Use of “designed” may also help capture research or trial activities that with the ultimate goal of large-scale environmental change, but that are not deployed applied at that level yet.
The purpose of the activity under CBD impact study’s definition is “to counteract
anthropogenic climate change and/or its impacts.” Generally, geoengineering is understood as seeking to reduce climate warming. Nevertheless, as other purposes are imaginable, a broader purpose of “producing environmental change on a regional or global scale” is used here, providing greater flexibility while also noting that this is “primarily for counteracting anthropogenic climate change or reducing its warming impacts.” Referring to climate
“warming” rather than the impacts of climate change, provides further differentiation from adaptation measures. “Environmental change,” as opposed to climatic, is also intended to broaden the scope of potential purposes. It is open for discussion whether this broadens the scope too much.
The CBD impact study’s choice of definition links the level of scale to the intent and purpose of the activity. However, it is not clear whether small-scale application of techniques, such as for research, may be covered. Further, the exact level of scale appears to turn upon the subjective intent of the actor, where it could be said that if the activity is not intended to effect climate alteration, even where feasible, the activity is not of scale intended to counteract
anthropogenic climate change and/or its impacts. The above alternative definition uses
“activities designed or undertaken with the purpose of producing environmental change on a regional or global scale.” While still linked to intent and purpose, the separation of these two
elements, via “or” reaches further beyond the actor’s intent. It also clarifies the trademark large-scale quality of geoengineering as occurring on a regional or global scale, not local.
Both definitions identify general categories of CDR and SRM, but do so, inter alia, by allowing room for other potential approaches and advances. Whereas the CBD impact study refers to
“sunlight reflection methods,” the above definition substitutes “reducing solar insolation.”
While both are appropriate, however, “solar” provides a slightly broader connotation, referring to heat or light relating to the sun and more closely to radiation, as opposed to only light.37 The CBD impact study’s definition is a useful and plausible starting point, as it captures the essence of the current debate in clear terms. However, its openness its also its weakness when it comes to determining whether or not a specific activity falls under the definition. We suggest that any definition, including the CBD impact study’s, that is used as a basis for a regulatory purpose would have to be complemented by further details on determining and measuring broad terms such as scale. This can be achieved in several ways. One approach, also addressing the difficulty of crafting a sufficiently broad definition to cover a wide range of methods, would be to complement the definition with a positive list that expressly mentions specific techniques -or activities- which are considered geoengineering. Such a list could be comprehensive and absolute, or left open, allowing for adaptation and interpretation as new methods and scenarios develop. Another option is to envisage a process or institution providing further guidance in advance or on a case by case basis.
37 Cf. the definitions in the online Oxford dictionary of “solar” and “insolation” to that of sunlight”.
5 The existing legal framework
While still small compared to the large amount of scientific literature, there have been a number of detailed legal analyses on how existing international law would apply to geoengineering techniques.38 This section (project work package 2) builds on this previous work.