6. UV Index in the 21st century
The inverse correlation between the total ozone column and the UV-B irradiance has been confirmed by measurements at several locations. These measurements show that long-term changes of the stratospheric ozone layer may modify the UV climatology, particularly at middle and high latitudes. An expected recovery of the ozone layer in the middle of the 21st century should therefore also allow for a stabilisation of UV-B radiation in the next decades.
The present trends and the behaviour of the ozone layer are strongly influenced by radiative, chemical and dynamical processes in the stratosphere. The significance of these processes may be augmented by human activities (e.g. the ”greenhouse effect”) and result in higher short-term variations of the ozone layer and UV-B radiation. The negative impacts on human health could be eliminated by a professional public awareness based on, for example, UV Index information. In any case, the next century brings a challenge for a more active and individual control of UV exposure and protective measures, at least for the large photosensitive part of the population.