Question 1

The Kigali Amendment, which entered into force in 2019, aims to phase down the production and consumption of which substances?

Accepted Answer

Hydrofluorocarbons (HFCs). The Kigali Amendment specifically targets HFCs to mitigate their high global warming potential. While HFCs do not deplete ozone, they are powerful greenhouse gases. This amendment is an extension of the Montreal Protocol framework.

Question 2

In which atmospheric layer is the highest concentration of the protective ozone layer found?

Accepted Answer

Stratosphere. The stratosphere contains about 90% of the Earth's ozone, forming a protective shield. This layer is located approximately 15 to 35 kilometers above the Earth's surface. It plays a crucial role in absorbing harmful solar radiation.

Question 3

Which international agreement was the first to recognize the need for global cooperation to protect the ozone layer?

Accepted Answer

Vienna Convention. The Vienna Convention for the Protection of the Ozone Layer was adopted in 1985. It served as a framework for international efforts but did not include legally binding reduction targets. The legally binding Montreal Protocol was developed two years later.

Question 4

What is the primary chemical element in CFCs that is responsible for the catalytic destruction of ozone molecules?

Accepted Answer

Chlorine. Chlorine atoms released from CFCs react with ozone to break it down into oxygen molecules. A single chlorine atom can destroy thousands of ozone molecules over its lifetime. This process is accelerated in the presence of polar stratospheric clouds.

Question 5

Which unit is standardly used to measure the total amount of ozone in a vertical column of the atmosphere?

Accepted Answer

Dobson Unit. The Dobson Unit (DU) is the most common unit of measure for ozone thickness. One Dobson Unit represents a layer of pure ozone that would be 0.01 mm thick at standard temperature and pressure. A typical healthy ozone layer is around 300 Dobson Units.

Ozone & Protocols — Set 1