Why are CFCs bad for the ozone layer?

As explained above, the primary cause of ozone depletion is the presence of chlorine-containing source gases (primarily CFCs and related halocarbons). In the presence of UV light, these gases dissociate, releasing chlorine atoms, which then go on to catalyze ozone destruction.

Then, why has the use of CFCs been phased out?

As previously discussed, CFCs were phased out via the Montreal Protocol due to their part in ozone depletion. However, the atmospheric impacts of CFCs are not limited to their role as ozone depleting chemicals. Infrared absorption bands prevent heat at that wavelength from escaping earth's atmosphere.

Additionally, what does ozone depletion potential or ODP ') measure? The ozone depletion potential (ODP) of a chemical compound is the relative amount of degradation to the ozone layer it can cause, with trichlorofluoromethane (R-11 or CFC-11) being fixed at an ODP of 1.0. It was defined as a measure of destructive effects of a substance compared to a reference substance.

Additionally, why do we need the ozone layer?

Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet (UV) radiation coming from the sun.

How is ozone made in the troposphere?

Ground level or tropospheric ozone is created by chemical reactions between oxides of nitrogen (NOx gases) and volatile organic compounds (VOCs). The combination of these chemicals in the presence of sunlight form ozone. Ozone in the troposphere is considered a greenhouse gas, and may contribute to global warming.

14 Related Question Answers Found

What chemicals harm the ozone layer?

Chlorofluorocarbons (CFCs) and other halogenated ozone depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion. The total amount of effective halogens (chlorine and bromine) in the stratosphere can be calculated and are known as the equivalent effective stratospheric chlorine (EESC).

Who signed the Montreal Protocol?

Montreal Protocol

Signed	26 August 1987
Condition	ratification by 20 states
Signatories	46
Ratifiers	197 (all United Nations members, as well as Niue, the Cook Islands, the Holy See and the European Union)
Depositary	Secretary-General of the United Nations

Is methane a greenhouse gas?

Methane in the Earth's atmosphere is a strong greenhouse gas with a global warming potential (GWP) 104 times greater than CO₂ in a 20-year time frame; methane is not as persistent a gas as CO₂ (assuming no change in carbon sequestration rates) and tails off to about GWP of 28 for a 100-year time frame.

Who invented CFCs?

Thomas Midgley

What is greenhouse gas emissions?

A greenhouse gas (sometimes abbreviated GHG) is a gas that absorbs and emits radiant energy within the thermal infrared range. The primary greenhouse gases in Earth's atmosphere are water vapor (H₂O), carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O), and ozone (O₃).

What did Mario J Molina discover?

Mario José Molina-Pasquel Henríquez (born March 19, 1943) is a Mexican chemist known for his pivotal role in the discovery of the Antarctic ozone hole. He was a co-recipient of the 1995 Nobel Prize in Chemistry for his role in elucidating the threat to the Earth's ozone layer of chlorofluorocarbon gases (or CFCs).

What important layer exists in thermosphere?

The thermosphere is the layer in the Earth's atmosphere directly above the mesosphere and below the exosphere. Within this layer of the atmosphere, ultraviolet radiation causes photoionization/photodissociation of molecules, creating ions in the ionosphere.

What is a Class 1 refrigerant?

Class 1: This class includes refrigerants that cool by phase change (typically boiling), using the refrigerant's latent heat. Class 2: These refrigerants cool by temperature change or 'sensible heat', the quantity of heat being the specific heat capacity x the temperature change.

What is photochemical smog and where is it usually found?

Photochemical smog, as found for example in Los Angeles, is a type of air pollution derived from vehicular emission from internal combustion engines and industrial fumes.

What effect does a temperature inversion usually have on air pollution such as smog?

Normally, air temperature decreases with an increase in altitude. During an inversion, warmer air is held above cooler air; the normal temperature profile with altitude is inverted. An inversion traps air pollution, such as smog, close to the ground. An inversion can also suppress convection by acting as a "cap".