The hydrosphere, primarily through water vapor in the atmosphere, absorbs a significant portion of ultraviolet (UV) radiation from the sun. This absorption helps protect life on Earth from harmful UV radiation and plays a role in regulating the Earth's climate.

The water cycle plays a role in transporting ozone-depleting substances, such as chlorofluorocarbons (CFCs), from the Earth's surface to the stratosphere, where they can cause ozone depletion.

Volcanic eruptions can release ozone-depleting substances, such as hydrogen chloride (HCl), into the atmosphere. However, natural processes, including volcanic eruptions, contribute a relatively small amount compared to human-made emissions.

Water vapor in the stratosphere can react with ozone-depleting substances, such as chlorine and bromine, leading to the formation of hydroxyl radicals (OH). These OH radicals can then react with ozone molecules, causing their breakdown.

Burning fossil fuels, such as coal, oil, and natural gas, releases various pollutants, including ozone-depleting substances, into the atmosphere. These substances contribute significantly to ozone depletion.

The Montreal Protocol is an international agreement designed to protect the ozone layer by phasing out the production and consumption of ozone-depleting substances. It has been successful in reducing the emissions of these substances and contributing to the recovery of the ozone layer.

Chlorofluorocarbons (CFCs) were widely used in various applications, such as refrigeration, air conditioning, and aerosol propellants, before being phased out due to their ozone-depleting potential.

Ozone depletion can lead to an increase in global temperatures as UV radiation can penetrate the atmosphere more easily, causing warming of the Earth's surface and contributing to climate change.

Ozone-depleting substances, such as CFCs, react with ozone molecules in the stratosphere, breaking them down and reducing the overall concentration of ozone.

Ozone depletion has various consequences, including increased risk of skin cancer due to higher UV radiation reaching the Earth's surface, reduced agricultural productivity due to UV damage to crops, and damage to marine ecosystems, particularly phytoplankton, which are sensitive to UV radiation.

Ozone-depleting substances, once released into the atmosphere, can take several years to reach the stratosphere, where they can cause ozone depletion.

Lightning strikes produce nitrogen oxides in the atmosphere, which can react with oxygen to form ozone, contributing to the replenishment of ozone in the stratosphere.

The hydroxyl radical (OH) plays a crucial role in the stratosphere by reacting with ozone-depleting substances, such as chlorine and bromine, converting them into harmless compounds and preventing them from causing ozone depletion.

Reducing the use of fossil fuels can help reduce the emissions of ozone-depleting substances and contribute to the recovery of the ozone layer.

With the implementation of the Montreal Protocol and the phasing out of ozone-depleting substances, it is estimated that the ozone layer will fully recover to pre-depletion levels in a few decades.