How Might Other Scale Problems Affect Restoration of an Atmospheric Ozone Balance?
The fourth type of risk to be considered is how other global scale problems might impact the atmospheric ozone layer. The major global ecosystems evolved together over billions of years and it is to be expected that they are intimately interconnected in complex ways. For example, a 2002 NASA study suggests that increases in various greenhouse gas (glossary) emissions are offsetting some of the improvements from reduction of ODCs. It is also reported that the increased greenhouse gas-induced warming of the lower stratosphere, where most of the ozone occurs, may be speeding up chemical reactions that destroy ozone by cooling the upper atmosphere. In addition, methane, also a greenhouse gas, may destroy atmospheric ozone independently of any warming effect (but anthropogenic sources are not named as a banned substance). The NASA study suggests that climate change may retard the anticipated recovery of atmospheric ozone expected from the Montreal Protocol. The issues of ozone depletion and
