Man-made climate change: facts and fiction

Important issues about climate change are summarized and discussed: A large body of evidence shows that the world climate is getting warmer. Climate models give a consistent explanation of this observation once human-made emissions of greenhouse gases are taken into account. Furthermore, the main source of greenhouse gases comes from the burning of oil, gas and coal, mainly in the industrialized countries. Without any change of behaviour, the possible predicted consequences of this climate change for the coming decades are very disturbing. Today’s (in)action’s will have long-term consequences for the entire biosphere and the living conditions of many future generations. The combination of the various points related to the climate change leads to a final question: “For how long will Humanity continue to bury its head in the sand?” • The average “earth” surface temperature is increasing [1]. Measurements of the earth’s surface temperatures, studied for the entire planet and during the last 50–100 years demonstrate that the earth is getting warmer. The so-called average global temperature has increased since the late 19th century by 0.6 ± 0.2 ◦C. Observations since 1976 indicate a significant temperature increase of 0.17 ◦C every 10 years. The observed temperature increase in the northern hemisphere is somewhat larger than that in the southern one. Obviously, when scientists talk about a world average, you will find regions where the observed temperature variations are below or above this “world” average. It is thus normal to find regions with larger changes. For example, measurements performed for the last 30 years in Switzerland show an increase of between 1 and 2 ◦C, corresponding to an increase of about 0.5 ◦C every 10 years [2]. It is not surprising either that some regions in the world even got colder. In addition, many phenomena consistent with this warming have been reported from all around the planet [3]: – With the exception of Antarctica and a few other places, a rapid glacier melting is observed all around the world. Dramatic changes are seen for Alaska, Greenland, the Himalaya, the Arctic ice shelf and many mountainous regions. The size of essentially all glaciers in the Alps has shrunk enormously, as easily observed even by hikers who visit the same glaciers in consecutive years [4]. – The winter season in many areas of the world became shorter, warmer, and the snow coverage decreased strongly. This estimate is given with a 95% confidence level.