Climate change manifests itself as an increase in the global average surface temperature. But we are also seeing ocean temperature and acidity on the rise, increases in weather variability and damages and frequency of extreme weather events such as heavy precipitation, heat waves and droughts. Germany as well has growing warmer and hotter over the years, and more so than the global average. As a result, the number of hot days increases (cf. 'Hot days' indicator). The increase in average temperatures is also changing the duration of individual seasons. As of yet we have only a partial understanding of the complex effects of these seasonal shifts on plants and animals.
The global annual mean temperature alone is of little climatological significance. We obtain more information from a given year's global mean deviation from the average for a longer period in the past. This shows whether one year was warmer or cooler than the climatological average. Usually a comparison is made with the period 1850 to 1900, which is also used by the WMO.
The 'German Strategy for Adaptation to Climate Change' envisages climate impact monitoring. Climate change impacts and adaptation in different areas are published in a monitoring report which is updated every four years.