1 Ozone Depletion and Refrigerant Environmental Impacts Free Online FlashCards

Where is most atmospheric ozone, and what does it do?

Most atmospheric ozone is in the stratosphere, roughly 15–35 km above Earth, where it absorbs much of the Sun’s harmful UV-B radiation.

How does ground-level ozone differ from stratospheric ozone?

Ground-level ozone is an air pollutant that can harm people and ecosystems; it is distinct from protective stratospheric ozone.

How do many ODSs release ozone-damaging atoms?

Many ODSs persist in the lower atmosphere long enough to reach the stratosphere, where ultraviolet light breaks them apart and releases chlorine or bromine.

Why can one chlorine atom destroy ozone repeatedly?

In catalytic reactions, chlorine helps destroy ozone and is regenerated, allowing one chlorine atom to participate in many cycles.

What is the ozone hole?

The ozone hole is a seasonal region of unusually low ozone—a thinning of the ozone layer, not a literal hole in the atmosphere.

How do polar stratospheric clouds contribute to rapid ozone loss?

Cold polar conditions, especially during Antarctic spring, promote reactions on polar stratospheric cloud particles that convert chlorine into forms sunlight can activate.

What are some former uses of CFCs?

CFCs were formerly common in refrigeration and air conditioning, foam production, and aerosol applications.

Why are HCFCs not ozone-safe substitutes?

HCFCs were transitional substitutes for CFCs. They still contain chlorine and can deplete ozone, though generally less per unit mass than CFC-11.

What makes halons a concern for the ozone layer?

Halons are bromine-containing chemicals used mainly in fire suppression; bromine is especially effective at destroying ozone.

How do ODP and GWP differ?

ODP compares a chemical’s ozone-depleting effect with CFC-11, assigned an ODP of 1. GWP instead compares heat-trapping effect with carbon dioxide over a specified period.

Why can HFCs affect climate without depleting ozone?

HFCs contain no chlorine, so they do not deplete stratospheric ozone. However, many have high GWPs and can contribute substantially to climate change if released.

What are the direct and indirect climate impacts of refrigerants?

Direct impacts occur when leaked refrigerant traps atmospheric heat. Indirect impacts come from the electricity used to operate the equipment.