A change in the composition of the stratosphere becomes relevant to society only if it has noticeable effects. This places the assessment of effects in a pivotal role in the problem of ozone depletion. Decreases in the quantity of total-column ozone, as now observed in many places, tend to cause increased penetration of solar UV-B radiation (290-315 nm) to the Earth's surface. UV-B radiation is the most energetic component of sunlight reaching the surface. It has profound effects on human health, animals, plants, microorganisms, materials and on air quality. Thus any perturbation which leads to an increase in UV-B radiation demands careful consideration of the possible consequences. This is the topic of the present assessment made by the Panel on Environmental Effects of Ozone Depletion.

The Panel at its tenth session called on partnerships and collaboration to address climate change, and stress the importance of involving experts from developing countries and countries with economies in transition in the activities of the Panel. The panel discussed and adopted various draft reports, and identified the following three areas on which IPCC needed to focus in its future work: Identification of gaps and uncertainties, preparations for the Third Assessment Report, and the development of methodologies on greenhouse gas inventories.