The greenhouse effect: a vital necessity
The greenhouse effect is a natural process that plays an essential role. Without it, the average temperature on the earth's surface would be –18°C rather than the current 15°C.
Every day, the earth receives a huge amount of solar radiation. Some of this energy is absorbed by the atmosphere, and the rest by the earth's surface, which turns it into heat and sends it back into the atmosphere in the form of infrared radiation. Greenhouse gases block part of this energy and radiate it back to earth. This is what we call the greenhouse effect.
The main greenhouse gases are water vapor (H2O) and CO2.
Global warming
Since the start of the industrial age, concentrations of greenhouse gases in the atmosphere have increased. This has led to an unnatural rise in greenhouse gas levels, potentially leading to global warming.
The average temperature has risen by around 0.6°C over the past 100 years. The highest temperatures have been observed in recent decades.
This increase in temperature is speeding up the evaporation process and thus leading to a change in the water cycle. On a large scale, this could lead to droughts and water shortages, causing forests to disappear and sea levels to rise.