Klaus Hasselmann, head of the Max Planck Institute for Meteorology, told an international climate conference that ended Friday that hot summers like this year will become typical in the future.
September is warming up to be the nicest in Germany this century, with temperatures of more than 86 degrees in some parts of the country replacing the typically cool, overcast days.
Since around the middle of the 19th century when industrialization began, the worldwide average temperature has risen about 1.3 degrees to nearly 60.3 degrees.
Meteorologists forecast that the average January temperature will rise from 32 degrees to 33.3 degrees in the year 2050 - meaning the snow will only stay on the ground briefly before melting.
Hasselmann, speaking at the conference organized by the Max Planck Institute, criticized politicians for not listening to scientists' suggestions for dealing with global warming, such as using more solar energy and burning less fossil fuels.
The United Nations opens its fifth international conference on climate change in Bonn on Oct. 25.