In 1958, Charles David Keeling proved for the first time that the CO₂ concentration in the atmosphere is increasing worldwide due to human activities.

Since pre-industrial times, the CO₂ concentration in the atmosphere has increased from 287ppm (parts per million) in 1750 to over 415ppm in 2022. A CO₂ concentration above 400ppm has not been observed on our planet for several million years. The CO₂ concentration has increased from 390ppm to almost 420ppm within 10 years. This steep increase is unprecedented in our Earth’s history.

In the city of St.Gallen, the main sources of CO₂ emissions are private individuals (49%) and companies (41%). In particular, activities related to energy, consumption, food and air travel are responsible for the majority of emissions.

Sources: Buis (2019), IPCC (2013), Monroe (2016), Tans & Bolin (2006), Linsey (2006), Stadt St.Gallen (2020)

In 1954, Chapin, Fuller and Pearson created the first practically applicable solar cell. Since then, the invention of solar panels has spread rapidly around the world.

In Switzerland, a fundamental transformation of the energy system is planned. Nuclear power plants will be shut down by 2050 and gasoline cars will be replaced by electric vehicles. Consequently, the demand for electricity will increase significantly. Therefore, the federal government plans to increase Switzerland’s nationwide solar power production tenfold, to 34 terawatt hours per year.

At the end of 2022, the installed PV capacity in the city of St.Gallen was approximately 25 MWp, which corresponds to an increase of 4.3 MWp compared to 2021. This results in an annual production of 25’000 MWh, which can supply approximately 6’500 households with solar power.

Source: Starowicz et al. (2023), Paganini et al. (08.09.2022), Umwelt & Energie Stadt St.Gallen (2022), St.Galler Stadtwerke (2022)

Meteorologist and climate scientist Guy Callendar first discovered the link between the rise in CO₂ in the atmosphere and global warming in 1938. However, the published document received little attention at the time.

Compared to the pre-industrial average of 1850–1900, global temperature has already risen by more than 1.1 °C by 2020. How disproportionately the temperature has increased since the beginning of the new century can also be seen in the graph. In particular, temperatures from 2011 to 2020 exceed those of the most recent warm period several centuries ago (about 6500 years ago). In Switzerland, the increase is even more than twice as high at 2.5 °C.

Source: American Institute of Physics (2017), MeteoSchweiz (o.D.), IPCC (2021)

Joseph Fourier discovered the greenhouse effect in 1824. The greenhouse effect is responsible for keeping our planet warm and habitable. At the same time, it is also a fundamental mechanism in climate change. The effect works by allowing solar radiation to fall on the Earth’s surface and be diffusely reflected from there into the atmosphere. In the process, part of the thermal radiation is retained by the greenhouse gases in the atmosphere, while the rest escapes into space. This means that the more such greenhouse gases there are in the atmosphere, the more thermal radiation is retained, which consequently leads to a warming of the earth’s surface.

The most important greenhouse gases include carbon dioxide (CO₂) and methane (CH₄). To counteract further warming, not only must new emissions be prevented, but existing ones must also be filtered out of the air.

Source: Rahmstorf (2013), Wild et al. (2017)