The discourse of geoengineering as one of the solutions to fight climate change is gaining strength. For some there is no choice but to pull them because what is emitted does not stop growing, for others it is a way to divert the issue from what is really important: reducing what we emit and financing mitigation and adaptation through the climate fund. But what does geoengineering propose? Some weather modification techniques are known and have been used for decades. The Moroccan government is, in fact, the last to make headlines because it recently took an official position on the artificial creation of rain and did so by confirming that it will continue to use this technique. In fact, as this newspaper already published, and following data from In Morocco, in 2021, an average of 21 cloud seedings were carried out; in 2022, 27; in 2023, 22, and this year, 70.
Israel, China and even Spain have resorted to these arts to cause a downpour (or in some cases prevent it, such as during the opening ceremony of the Beijing Olympics). To do this, substances such as silver iodide are dispersed in the clouds to increase their condensation and form raindrops. Since the 60s there have been different projects known as the one developed byr USA, the Stormfury project, dedicated to reducing the intensity of hurricanes or the one implemented by China during the 70s that served to increase precipitation between 10 and 15% in some regions. «These experiments have almost no effect and require a huge investment, which is why we see that China and the Emirates put a lot of money into causing rain in the large deserts. In Spain it was carried out, especially in the 60s and 70s, but today this cloud seeding is prohibited and penalized. Now Morocco is trying to use it, but it must be clarified that the effects are very local,” comments Jorge Olcina, professor of Regional Geographic Analysis at the University of Alicante.
One of the questions raised by these climate modification technologies, in addition to the environmental consequences of shooting chemicals into the atmosphere, has to do with geopolitics. When China announced a few years ago its intention to develop a massive program by 2025 in the north of the country in a territory of 5.5 million km², the responses of its neighbors were immediate. The UN is also suspicious and many organizations and scientists consider that proposals and experiments that have to do with climate modification are increasing with the excuse of the fight against climate change but only to divert attention from reducing emissions or promoting initiatives. private. A year ago 450 scientists united in an open letter in which they expressed their concern about these issues claiming that uncertainties cannot be eliminated with laboratory experiments since, in most cases, only pilot tests have been carried out.
One of the theoretical approaches of so-called geoengineering has to do with modify solar radiation so that the Earth stops warming at the rate it does. It is proposed to release tiny particles into clouds to reflect the sun or create clouds in ocean areas. “They fall into the category of experiments, ideas that are a little extravagant,” says Jorge Olcina.
Extract carbon
«We have issued so much that there is no longer a single perfect solution to tackle the problem, but we are going to need to do everything. On the one hand we can talk about solutions based on nature, such as reforestation, afforestation or changing land uses (although here we must consider whether it is competing with food production) and on the other, about technology,” he comments. Juan Alcalde, expert in CO2 capture and storage and researcher at the Barcelona Geosciences Research Institute (GEO3BCN).
The so-called CCS or capture projects They have existed for years and are increasingly being proposed as an applicable geoengineering solution, especially for industrial activities that are considered difficult to decarbonize, such as steel or cement production. However, today the projects are few; There are about 60 in the world and “most are for enhanced oil recovery, therefore they are not considered a clean technology. The best-known capture and storage facilities are the Norwegian Sleipner and Snøhvit, which have been operating and storing carbon derived from gas production for 25 years. They are considered a geoengineering solution, because the objective is to store the sequestered CO2 in a geological reservoir permanently,” says Alcalde, who believes that this is the main reason why these solutions are opposed, “as happens with all activities that involve the geological environment: from mining to biocarbon extraction. However, CO2 is not dangerous or poisonous and the trick is that the longer it is stored, the more trapped it becomes because it ends up turning into rock. In addition to storage, today there are also a type of plants, called CCUS, that reuse it in new processes: from plastic production to food use. However, “most of the time these second uses are not neutral in emissions or do not reduce emissions because they do not remove them from the atmosphere, they only avoid them,” says Alcalde.
Historically the Co2 capture has been used in coal-fired power plants in which the Co2 was injected back into the process, but now proposed for other industrial projects and opens the door to two possibilities: direct capture of CO2 from the air (DAC) and capture associated with bioenergy (BECS). «Direct capture is a fairly incipient technology that filters atmospheric CO2. The difficulty is that carbon dioxide is very little concentrated in the air. Of a million particles, 400 are carbon dioxide. You have to concentrate a lot to extract it, although the trick is precisely that it is a negative emissions technology, since it traps what has already been emitted. Another challenge, in addition to the technical difficulty, is that it costs hundreds of dollars to extract a ton of CO2. The largest pilot in the world is in Iceland and manages to remove 4,000 tons a year. BECCS are the other technology that is considered negative emissions and is linked to bioenergy. It would be about generating electricity with biomass (for example, rest of prunings that have already sequestered CO2 during their life, and burning it to produce energy, while capturing and storing the carbon from combustion,” he says.
In Europe There are almost 200 potential capture and storage projects that could remove more than 150 million tons of CO2e. So says the Institute of Energy Economics and Financial Analysis, which published a recent report in which it warns that European taxpayers could have to face a bill of 140,000 million euros for a portfolio of carbon capture and storage projects.
The World Economic Forum says in a recent publication that direct capture in the Ocean through a series of electrochemical processes can potentially be more effective and cheaper than direct capture in the atmosphere. The ocean contains 150 times more CO2 than the atmosphere, remember. There are several private proposals in this regard. For example. Brineworks in the Netherlands wants to use electrolysis to extract CO2 while producing hydrogen.
The military interest in climate modification cannot be forgotten. In the 1980s, the United States developed the so-called High Frequency Active Aurora Research Program or HAARP, capable, they say, of causing natural disasters. It intended to examine the processes that occur in the ionosphere under solar influence and improve underwater communications or perform remote mapping controls or locate underground structures. In 2014, though the structure became property of the University of Alaska Faribanks and in theory continues to be used for academic purposes.
Restore ecosystems
►Miguel Ángel Mateo is a researcher at the Aquatic Ecology Research Center (CEAB-CSIC) and leads the state group of experts on blue carbon. For him “this great problem of excess carbon has few solutions. The most obvious thing is to reduce emissions and then remove carbon from the atmosphere either using removal and storage techniques or with options that are not artificial. That is to say, enhancing natural ecosystems that already remove it. Forests are the great carbon sinks, but the oceans also have coastal vegetation masses such as mangroves, marshes and seagrasses that absorb them. This is the blue carbon family. Since 2012, they have aroused a lot of interest due to the development of the carbon market worldwide. In Spain we have created a group of experts whose main objective is to make a white paper or strategy for Spain, first inventorying the blue carbon of Spain, Portugal and the islands and then calculating the capture potential of these areas. Blue carbon family ecosystems are removing between 0.8 and 2% of carbon, but that is not the problem. It is similar to what happens with permafrost, because these grasslands and marshes currently accumulate a volume equivalent to two years of human activity in carbon. “In addition, the conservation of these areas has other advantages, because these areas are a source of food for many species and form natural dikes that protect the coast from storms.”