Ist die gegenwärtig verstärkte Einwanderung südlicher Fischarten in die Nordsee schon eine Folge des Treibhauseffektes

Due to the greenhouse effect,a long term warming of the atmosphere is expected. For most people the last relative mild winters and the previous two hot summers are clear signals for such a climatic change. Changes in species compositions and the sudden arrival of southern species in the North Sea are explained as consequences of the greenhouse effect. Comparing the situation in the last decades an attempt is made in this article to show the natural variability in the occurrence and to give an answer to the above question.