Changes in the size of glaciers, in the altitude of the alpine tree-li
mit, and variation in the width of tree-rings during the Holocene clea
rly indicate that the average Scandinavian summer temperature has fluc
tuated. During warm periods it has been about 2 degrees C warmer than
at present; during cold periods it has been almost as cold as it was d
uring the coldest decades of the previous centuries. Superimposed on t
hese long-term variations, which have lasted from 100 to 200 years, ar
e short fluctuations in temperature. The Scandinavian chronology, whic
h is based on glacier and alpine tree-limit fluctuations as well as on
dendrochronology, is well correlated with the changes in climate, whi
ch studies of ice cores from central Greenland have revealed. It is th
erefore believed that the Scandinavian climate chronology depicts cond
itions typical of a large area. The Scandinavian record is compared wi
th data concerning solar irradiation variations estimated as C-14 anom
alies obtained from tree-rings. A correlation between major changes in
climate and variations in solar irradiation points to a solar forcing
of the climate. This means that there is no evidence of a human influ
ence on climate so far.