Ozone is a greenhouse gas, and ozone depletion in the upper atmosphere is believed to have had a slight cooling effect on the global climate. Thus, ozone depletion in the upper atmosphere has not contributed significantly to global warming, although ozone depletion remains a concern because of its ability to block harmful ultraviolet radiation from reaching humans and wildlife.

What's in the Working Group I Summary for Policymakers on the Physical Science of Climate Change? (opens new window) What's in the Working Group II Summary for Policymakers on Climate Change Impacts? (opens new window) See similar questions...

The human health and environmental concerns about ozone layer depletion are different from the risks we face from global warming. Nevertheless, the two phenomena are related in certain ways. Some pollutants contribute to both problems and both alter the global atmosphere. Ozone layer depletion allows more harmful ultraviolet (UV) radiation to reach our planet?s surface. See similar questions...

The ozone layer is a thin layer of gases that surrounds the earth. It acts as a sunscreen for the earth, blocking out most of the sun's UV radiation. Over the last few years, the ozone layer has become slightly thinner, allowing more damaging UV rays to reach the earth's surface than before. See similar questions...

To our knowledge there are no studies concerning UV-B effects on penguins. As their eyes are exposed to a lot of UV due to the high reflectivity of snow and a marked enhancement during the ozone hole, investigation into the impact on penguins is desirable. The fact that penguins are visual predators, eating krill or fish in the water column, would make any eye damage an important issue for survival. See similar questions...

Two 19th-century scientists are associated with the discovery that increasing carbon dioxide in the atmosphere warms the entire planet: French researcher Jean Baptiste Fourier and Swedish scientist Svante Arrhenius. Their identification of what came to be called the greenhouse effect (see box at right) applies to both natural and human-produced additions of CO2. See similar questions...

The ozone layer has been depleted gradually since 1980 and now is about an average of 3% lower over the globe. The depletion, which exceeds the natural variations of the ozone layer, is very small near the equator and increases with latitude toward the poles. The large average depletion in polar regions is primarily a result of the late winter/spring ozone destruction that occurs there annually. See similar questions...

Significant reductions in ozone content in the stratosphere above the Arctic have been observed during the late winter and early spring (January-March) in 6 of the last 9 years. However, these reductions, typically 20-25%, are much smaller than those observed currently each spring over the Antarctic (the ozone hole). The difference between ozone content in the two polar regions (see figure below) is caused by dissimilar weather patterns. See similar questions...

First, it's important to know that ozone plays two different roles in the atmosphere. At ground level, "bad ozone" is a pollutant caused by human activities; it's a major component of health-damaging smog. The same chemical occurs naturally in the stratosphere, and this "good ozone" acts as a shield, filtering out most of the ultraviolet light from the Sun that could otherwise prove deadly to people, animals, and plants. See similar questions...

Effects are already visible in every ecosystem: coral bleaching, changes in flowering seasons, changes in bird and insect and mammal and fish migrations, melting of glaciers, thinning of polar ice caps, disappearance of cloud forests, warming of groundwater, changes in tree ting thickness, etc. See similar questions...

This is a matter of considerable speculation in the climate research community. It is plausible that a warmer earth would produce more and stronger El Ninos. There is some evidence that the earth has warmed over the past two decades, and there is no doubt that El Nino has been much more frequent in that time. See similar questions...

Ozone is very rare in our atmosphere, averaging about three molecules of ozone for every 10 million air molecules. In spite of this small amount, ozone plays vital roles in the atmosphere. This document provides answers to some of the questions that are most frequently asked about ozone and the changes that have been occurring in recent years. See similar questions...

The "ozone hole" is a loss of stratospheric ozone in springtime over Antarctica, peaking in September. The ozone hole area is defined as the size of the region with total ozone below 220 Dobson units (DU). Dobson Units are a unit of measurement that refer to the thickness of the ozone layer in a vertical column from the surface to the top of the atmosphere, a quantity called the "total column ozone amount." Prior to 1979, total column ozone values over Antarctica never fell below 220 DU. See similar questions...