# The Buying Time Argument within the Solar Radiation Management Discourse
## 2 Building Blocks of BTA
### BTA and the Costs of Abatement
Thus, we discard this \"optimality\" approach on theoretical grounds. On more empirical grounds, the costs of SAI deployment may be underrated by its proponents [34]. Interestingly, recent economic models indicate that global economic benefits of SAI are rather small and may even become negative under an RCP4.5 scenario [35]. The second economic approach is conceived as the standard price approach. A normative yardstick is adopted as supreme standard (or objective). The Paris goal of \"well below 2 \({}^{\circ}\)C\" can be regarded as such a standard, as it specifies the objective of Art. 2 of the United Nations Framework Convention on Climate Change (UNFCCC) to avoid dangerous anthropogenic interference with climate system. Given such a standard, climate economics may assess how to reach such goal efficiently. BTA, then, becomes part of such \"least cost planning\". The negative peak of aggressive GHG abatement might be a global recession, but prudent economics buys time in order to flatten the curve in terms of loss of global GDP growth. If so, a buying time deployment of SAI might aim at (at least) two different objectives: On the one hand, SAI shaves the peak of negative impacts, while on the other hand, it optimizes the distribution of opportunity costs of transition towards low-carbon economies. [PERSON] [3] has distinguished two types of climate goals: primary climate goals, that aim at preventing climate tipping points, and secondary climate goals, that focus on reducing pressure for adaptation and mitigation. Primary climate goals can arguably be backed by general climate ethical considerations, whereas secondary climate goals lie within the scope of economic rationale, which, of course make some normative assumptions. Reducing the social, economic and civil costs of climate policies is a worthwhile objective and can reasonably be put into play alongside primary climate goals. Hence, a time-buying deployment of SAI will address both the primary and the secondary climate goal. Time will be bought for capital turnover, technology diffusion, adaptation, etc. Such perspective allows placing a morally motivated \"peak shaving\" into the foreground of BTA under a perspective of \"least cost planning\". The costs to be avoided are (a) moral costs in terms of loss and damage, and (b) economic costs in terms of capital turnover, loss of jobs, loss of growth rates and the like. Such a two-fold perspective of avoiding loss and damage and curb the opportunity costs of transition even strengthen the BTA. To summarize this section, six essential elements (\"building blocks\") of the BTA have been identified on a reflective reading of BTA proposals:  
1. Primary climate goal--Averting dangerous climate impacts by \"humanitarian\" peak shaving;
2. Secondary climate goal--Reducing pressure of abatement and/or adaptation, \"least cost planning\";
3. Complementarity (amendment), not substitution to emission abatement;
4. Proper governance;
5. Temporary deployment only, realistic exit-strategy. Of course, those requirements can be contested (for example [36]). We believe them to be the core elements of the BTA. From those building blocks, we will now forge a comprehensive BTA that holds logically and suffices morally.