According to critics of this approach, it would be impossible to have certainty about the results without setting up large-scale experiments, which would amount to an effective use of these technologies. If any problem in short, during the test phases, it would already be too late to remedy it without paying a very high price. The effects could also prove to be unequal in different areas of the planet, opening up to the risk of a future of climate inequality. And it is difficult to imagine who should make the decision to resort to such strategies, given that the consequences of its use would necessarily turn out to be global: a single power, such as the US, could decide that it is worth taking the risk for everyone?
If using aerosol in stratosphere is the most studied methodology of solar geoengineering, it is certainly not the only one to have been proposed. Another very promising approach is defined marine cloud brightening (clearing of marine clouds), and plans to disperse salt marine in the lower atmosphere (particularly on the oceans) to act as condensation coresgiving rise to clouds which would then reflect sunlight away from Earth. Another potential strategy is the cirrus cloud thinning (or thinning of the cirrus clouds), which aims to act on the cirrus clouds, clouds present in the high troposphere which in some conditions can contribute to trap heat radiated from the earth’s surface, with results similar to those of the greenhouse effect. The theory involves the dissemination of microparticles which can act like cores from freezingthat is, substances that trigger the formation of ice crystals into the atmosphere, to be released in the areas where cirrus clouds form. This – theoretically – should lead to the emergence of clouds with a shorter duration and a lower ability to trap heat, thus increasing the amount of energy that is radiated into space, and consequently reducing the planet’s temperature.
For both of these approaches, however, many of the objections apply cited for it stratospheric aerosol intervention. The situation is different for a strategy recently proposed by the team of researchers of the Mit of Boston led by ours Carlo Rattiwhich would allow to minimize the potential undesirable effects and the unknowns of the solar geoengineeringhowever, at the cost of a much higher complexity of implementation. The proposal is to use a fleet of bubbles to form a screen in space, which reduces the amount of sunlight directed towards our planet. The space bubbles would be composed of a very thin layer of a material capable of withstanding temperatures and the conditions of the open space, inflated directly into the space, and positioned at the point of Lagrange L1. With a fleet of the size of BrazilRatti and his team calculate they can decrease 1.8% the amount of radiation solar reaching Earth, enough to completely offset the current temperature rise caused by the global warming. Since these are bubbles, in case of problems it would be enough to burst them to return in a moment to the starting situation. The unknowns are obviously not lacking in this case either, and there is no need to explain what the complexity of such an undertaking would be. But if we were to really find ourselves in a dead-end climate emergency situation, at least space bubbles would have the benefit of not affecting the environment in any way. biosphere and with the chemistry of the atmosphere terrestrial.
Where are we at?
To date, climate geoengineering projects aimed at reducing the absorption of solar radiation by our planet they remain entirely theoretical. The limitations and concerns that we have mentioned, shared by a good portion of the scientific community (and civil society), have held back their development, but the time seems increasingly ripe to see some first attempts at application. These are technologies of which it is very complicated foresee the results, but all in all extremely easy to put into practice. For this reason, a framework international that regulates their study and development, given that the planet’s climate is a global theme par excellence. The US government working group, which is supposed to involve NASA, Noaa (national oceanic and atmospheric administration), Department of Energy and other federal agencies, could be an opportunity to provide guidelines to be proposed later in the international forum. A good starting point – he writes the Mit Technology Review – it could be a relationship published by NationalAcademies of Sciences, Engineering, and Medicine in 2021, in which the authors stressed the need to coordinate activities in this field at an international level, to focus efforts on basic research and not on the application of these technologies, and to limit public investments to a fraction of the dedicated budget the fight against climate change. All that remains is to wait the next moves of the American governmenttherefore, to find out if they will be sufficient to overcome the reluctance that for now have put a damper on any attempt to start the discussion within the United Nations.