Water vapor, not CO2, in the atmosphere is the primary reason explaining why the climate in Europe is warming – according to research from the World Radiation Center in Davos, Switzerland, recently published in the journal Geophysical Research.
A research team led by Dr. Rolf Philipona utilized research networks and weather stations across Europe to measure temperature, humidity, and longwave radiation – which play a crucial role in the greenhouse effect. Observations from 1995 to 2002 indicate that the amount of longwave radiation directed towards Earth in Europe has significantly increased, whereas solar radiation has not. Longwave radiation originates from gas molecules such as CO2, methane, and water vapor (which absorb solar radiation after it interacts with the Earth’s surface and reflects back into the atmosphere). Researchers calculated that the increase in longwave radiation is partly due to high concentrations of gases like CO2 – considered a cause of “human-induced greenhouse effect.” However, the increase in water vapor seems to have a more substantial impact, accounting for about 70% of the temperature rise recorded in the study.
Not all regions in Europe are affected equally. Eastern European countries are experiencing a warming trend with an increase of approximately 2 degrees Celsius per decade – significantly more than Western European countries. According to the new research, this may be due to differences in humidity. Humidity has increased rapidly in the East but not in the West, where drought conditions on the Iberian Peninsula may have limited water evaporation.
