The fight against global warming is the main challenge of our age. Reducing the amount of CO2 in our atmosphere has become not only urgent and healthy, but vital.

In Mantova's Piazza Mantegna, chemist and university professor Gianfranco Pacchioni held an outdoor lesson, complete with blackboard, ranging from chemistry to biology to geological history.

Although CO2 has been demonised in many ways, it is in fact fundamental for the existence of life itself. At the time of its formation the Earth was mainly covered in carbon and water, which allowed the creation of cyanobacteria. These primitive living beings were able to transform C2 and H2O into energy and carbohydrates, with the process called photosynthesis. On the other hand, humans themselves are constantly engaged in the opposite process: whenever we eat we produce CO2, by burning glucose and carbohydrates.

So why is this molecule considered such a problem and when did it start being so?

Keeling’s 1959 experiment demonstrates how CO2 became harmful for our existence. He recorded the concentration of CO2 in the air at Hawaii for several years: during the hundred years up to 2023 it increased from 315 ppm to 420 ppm. The significance becomes clear when we consider ice cores analysed in the late 1990’s, which show the shifting of concentration of CO2 in the last 800 thousand years. Until 1800, the concentration never exceeded 320 parts per million.

How can we return to normal levels? Pacchioni offered two different solutions: CCS (Carbon Capture and Storage) and CCUS (Carbon Capture, Utilisation and Storage). The latter involves the use of CO2 to produce e-fuels: this is the exact same process as photosynthesis and produces so-called green hydrogen, as opposed to the “grey” hydrogen produced by the burning of methane.

It is thus important not to consider carbon dioxide as an absolute enemy, but rather a useful source of energy and life which, however, must be reduced by all means.