Founded in 2017, the Zurich-based company Climeworks has developed large sensors capable of filtering the air and capturing carbon dioxide, and then placing it underground: a technology that is already giving results in the companies in which it is used. . The company’s ambitious goal is to eliminate 1% of global CO2 emissions by 2025.
The report of the Intergovernmental Panel on Climate Change (IPCC) of 8 October 2018 leaves no room for doubt: all scenarios that allow us to limit global warming to 1.5 ° C presuppose an extraction of enormous quantities of CO2 from the atmosphere – specifically between 100 and 1000 billion tons – by 2100. In other words, two to twenty times the current annual total of world greenhouse gas emissions.
Scientists call the extraction of CO2 from the atmosphere “negative emissions”. On paper, various options allow us to arrive at this result. The simplest is to plant forests: trees are in fact very effective carbon sinks, since they are able to capture CO2 through photosynthesis and store it in the trunk, in the branches, in the roots and in the soil. But according to the IPCC, a tropical forest twice the size of France would have to be planted to absorb CO2 between 100 and 1000 billion tons. A second possibility is to resort to the so-called bioenergy, which consists in sowing fast-growing plants. Again, by 2050 more than 700 million hectares should be allocated to this type of plantation: an unrealistic scenario.
However, a third way is emerging: the direct capture, through physico-chemical procedures, of the CO2 present in the atmosphere and subsequent storage. Various companies are exploring this path, among them the Swiss startup Climeworks, which has developed a sort of huge extractor capable of filtering the air and capturing carbon dioxide to then introduce it into the subsoil. The Zurich company aims to eliminate 1% of world emissions in this way by 2025. Behind this project, which is far from absurd, are Christoph Gebald and Jan Wurzbacher, two engineers from the ETH Zurich (ETH).