Lennart Bengtsson: Global climate change and its relevance for a global energy policy.

by H. von Storch, March 12, 2013 in DieKlimazwiebel

The relation between temperature and greenhouse gases in its very simplistic form has been known since the second half of the 19thcentury. The effect of the greenhouse gases can be seen as a warm overcoat preventing the surface in radiating away the heat to space. However, the warming is a complex process incorporating the dynamics of atmospheric and ocean flows and interactions of the many components of what is now called the Earth’s system. This includes in addition to the atmosphere, the oceans, the land surfaces and the land ices. Its study requires advanced computer models and other tools for its analysis and understanding.  It also requires accurate observations for validation and monitoring as well as special measurements for the development of many crucial aspects of the models. It is in fact an immensely complex undertaking that is virtually impossible to explain to the public in a readily understandable way. This has lead to a tendency towards oversimplification that has contributed more to confusion than to a thorough understanding. However, because of the strong public interest we are now facing a dilemma as the public and the political community have become too much involved in the climate change debate influencing the actual science and this not necessarily in a positive way as it implies an arbitrary selection of priorities and preferential issues.


Natural processes drive climate and practically all kinds of extreme weather have always been part of the climate and are practically unrelated to the modest warming we so far have had. The effect of increasing greenhouse gases is a slow but relentless process that will have to be dealt with but will require more time and better insight in key processes.Some events are seen as very dramatic as the reduced Arctic summer ice, others, even more puzzling, such as the surprising lack of warming in the tropical troposphere is hardly discussed.

The problem is that the global warming is mainly caused by the emission of carbon dioxide and thus directly related to energy production by fossil fuels that has dominated and still dominates the energy production by more than 80%. To significantly reduce or eliminate fossil fuel is not feasible on a time-scale shorter than several decades, as it requires fundamental technical breakthrough in energy generation or alternatively a major change in our life stile. As the second alternative is hardly possible to achieve in a world with mostly open societies, it is obvious that the world community is facing a gigantic challenge. Additionally many parts of the world are suffering because of a lack of suitable energy and the need is further underpinned by the fact that the world’s population will increase by another two billion humans in the next three decades.

Some comments on the present situation