Imagine an autumn day in the not-so-distant future. At the Mauna Loa Observatory in Hawaii, a historic event is taking place. For the first time since measurements began in the mid-20th century, the values concerning atmospheric change continue to drop. Whereas they would normally rise again after the end of the summer due to seasonal effects, the downward trend now persists. The observations make world news, with headlines across global media announcing the beginning of the end of the climate crisis. «We did it. We fixed the climate» some leaders already proclaim.
It could be the premise for a science fiction story. Yet, it is not entirely fiction. Capturing CO2 – the main greenhouse gas – from the air is technologically possible. So, in principle, the excess CO2 in the atmosphere, which largely drives today’s climate change as we have been pumping it in since the Industrial Revolution, could also be removed. This means the current concentration of over 427 parts per million (ppm) could be brought down to a lower value, for example, to 310 ppm, the level when daily CO2 measurements began at the Mauna Loa Observatory. It would be as if we are rewinding the climate’s history by several decades.
