Reduce the heat absorption of the land injecting aerosols into the atmosphere from high-altitude aircraft possible, but very expensive with current technology, and it is unlikely that it was secret.
These are the key findings of new research published in 'Environmental Research Letters', which analyzed the capabilities and costs of various methods to supply sulphates to the lower stratosphere, known as stratospheric aerosol injection (SAI).
The researchers examined the costs and practicalities of a hypothetical large-scale "solar geoengineering" project that will start within 15 years. Your goal would be reduce by half the increase in radiative forcing (the difference between sunlight absorbed by the Earth and the energy that goes back into space) anthropogenic, deploying material at altitudes of around 20 kilometers.
They also analyzed whether such an idealized program could be kept secret. "Solar geoengineering is often described as 'fast, cheap and imperfect'," study co-author Gernot Wagner of the John A. Paulson School of Engineering and Applied Sciences at Harvard University in the United States said in a statement. – Although we do not make any judgment about the suitability of the UPS, we do demonstrate that a hypothetical implementation program that will begin within 15 years, even if highly uncertain and ambitious, would be technically possible strictly from an engineering perspective. "
This expert points out that the cost would be an average of around 2,000 to 2,500 million dollars per year for the first 15 years. The researchers confirm previous studies that analyze the low direct costs of the possible intervention of geoengineering of stratospheric aerosols, but reach those numbers with the help of direct contributions from the aerospace engineering companies to specify what the document "SAI Lofter (SAIL) consists of. ) ".
It would take a completely new airplane design
"I was intrigued by the engineering questions surrounding SAI and the numerous studies that claim to show that modified existing aircraft could do the job, which is not the case – in fact, a completely new airplane design would be needed to make UPSs under parameters reasonable, although completely hypothetical. No existing aircraft has the combination of altitude and load capabilities required, "says co-author of the paper, Wake Smith, professor at Yale.
"We developed the specifications for UPS with the direct input of several aerospace and engine companies, which is equivalent in weight to a large narrow-body passenger plane, but to keep the flight level at 20 km, approximately double the wing area of an aircraft of equivalent size, and double the thrust, with four engines instead of two ", details Smith, who held previous positions as executive director of 'Pemco World Air Services' (a leading aircraft modification company).
"At the same time, its fuselage would be chubby and narrow, sized to accommodate a heavy but dense mass of molten sulfur instead of the large volume of space and air required for passengers," says the director of operations of Atlas Air. Worldwide Holdings' (a global cargo airline), and president of the Flight Training Division of Boeing.
The team estimated the total costs of development in less than 2,000 million for the fuselage, and another 350 million to modify the existing engines. The new aircraft would comprise a fleet of eight in the first year, reaching a fleet of just under 100 in 15 years. The fleet will do just over 4,000 missions a year in the first year, reaching more than 60,000 per year by the year 15.
Dr. Wagner emphasizes: "Given the potential benefits of halving projected increases in radiative forcing from a particular date forward, these figures invoke the 'incredible economics' of solar geoengineering. Dozens of countries could finance that program, and the required technology is not particularly exotic. "However, according to the authors, this should not reinforce the often pointed fear that a country or operator could launch a clandestine SAI program in an unsuspecting world.
Smith concludes: "No overall SAI program of the scale and nature debated here could reasonably be expected to be kept secret, even our hypothetical 'One Year' implementation program. involves 4,000 flights at unusually high altitudes in aircraft of the size of a passenger plane in several flight corridors in both hemispheres. This is too much aviation activity to not be detected, and once detected, this type of program could be dissuaded. "