complément du document aurora par david keith.pdf
Supplemental Online Material: Cost Analysis of Stratospheric Albedo Modification
Introduction to This Study
The goal of this study is to use engineering design and cost analysis to determine the
feasibility and cost of a delivering material to the stratosphere for solar radiation management (SRM). This study does not examine effectiveness or risks of injecting material
into the stratosphere for SRM. Its goal is simply to compare a range of delivery systems
on a single cost basis.
Mass per year
1 Million tonnes
40 to 100 kft
Payload dispersal rate
0.1 to 0.003 kg/m
The rough order of magnitude needed for planetary scale SRM. Values of 3M, and 5M also
considered for some systems.
SRM is generally thought to be most effective
in this altitude range, with current models
showing increased effectiveness above 60 kft.
Equivalent to water. Payload density sufficiently large that payload volume can be ignored.
Release rate per meter flown to obtain ideal
particle size. Goal of 0.03 kg/m.
The primary vehicles examined to lift particulate to stratospheric altitudes and disperse
them at a predetermined release rate are airplanes and airships; rockets and other nonaircraft methods such as guns and suspended pipes are also surveyed.
Existing airplanes, modified airplanes, and clean sheet designs requiring development
and testing are examined. Fleet setup cost analysis looked at costs of starting up a geoengineering operation by purchasing airplanes, designing and acquiring new airplanes
or airships, or constructing other systems. Operations cost analysis looked at the fuel
costs, electricity costs, personnel costs, maintenance costs of systems. Finally, yearly
costs combined operations with depreciation of the system’s initial costs as well as financing charges over the 20-year system life.
The following is a list of terms and their definitions used:
Research, Development, Testing & Evaluation
Cost to set up new aircraft fleet, including RDT&E and acquisition costs of aircraft.
Similarly, cost of developing and constructing non-aircraft systems.
Cost of operating aircraft fleet, including maintenance, fuel, personnel, spare parts
for 1 year. Similarly, cost operating non-aircraft systems.
Yearly Total Cost
Combined cost of operations and depreciation of aircraft fleet or system over 20-