Glaciers both respond to climate and are a clear indicator of recent changes in local climate.  

Engabreen, an outlet glacier from Svartisen, in 2001 (left) and 2020 (right).

Glaciers respond to local climate, and many glaciers (including those in mainland Norway) are especially sensitive to winter precipitation, which governs how much snow falls on the glacier during the winter months, and to summer temperature, which controls how much snow and ice melts during the summer months. 

 With few exceptions, glaciers globally have retreated in response to recent climate change, especially warmer temperatures. This effect is amplified in many regions due to greater warming at higher latitudes and higher altitudes (also called elevation dependent warming). A recent IPCC report shows changes in the mass budget of glaicers in different regions. 

 The future evolution of glaciers in different regions has been projected by many models, and for different emissions scenarios. These show that the current patter of glacier loss is projected to continue. 

The Norwegian glacier museum has a good overview of glaciers and climate here:

The IPCC special report on the Ocean and Cryosphere in a Changing Climate can be seen here: