Does ozone depletion pose any danger in the tropics?
Probably not. Increases in UV-B radiation are unlikely, since no significant trend in stratospheric ozone has been observed in the tropics. However, viewing the biosphere as a unit, there may be indirect effects of ozone depletion at other latitudes on tropical ecosystems. If ozone were to be depleted in the tropics, this would constitute a serious danger because of the naturally occurring high levels of UV-B radiation due to the high solar angles and already relatively low normal stratospheric ozone levels. • Do we need to worry about relatively small increases in UV-B due to ozone depletion, when natural variability is so much larger? Yes. The change in UV-B from ozone depletion is systematically upward. The natural variability (e.g., from time of day, or clouds) can be larger, but goes in both directions, up and down. While the evidence for ozone depletion is very strong, there is little evidence for long-term changes in cloud cover. Many detrimental effects of UV-B are proportional
