In 2002 AD, according to research, the concentration of CFCs reached to

Options

A. 368 ppm
B. 1750 ppb
C. 261 ppt
D. 326 ppb

Answer

To answer the question regarding the concentration of CFCs (chlorofluorocarbons) in the year 2002, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding CFCs**:
- CFCs are chlorofluorocarbons, which are chemical compounds that have been used in various applications such as refrigeration, air conditioning, and aerosol propellants.
- They are known for their role in depleting the ozone layer in the stratosphere.

2. **Impact of CFCs**:
- The depletion of the ozone layer by CFCs leads to increased UV radiation reaching the Earth's surface, which can have harmful effects on human health and the environment.

3. **Research Data**:
- According to research conducted in 2002, we need to find the specific concentration of CFCs in the atmosphere during that year.

4. **Concentration Values**:
- The options provided for the concentration of CFCs are:
- 368 ppm (parts per million)
- 750 ppb (parts per billion)
- 261 ppt (parts per trillion)
- 326 ppb (parts per billion)

5. **Identifying the Correct Concentration**:
- From the research data mentioned in the video transcript, the concentration of CFCs in 2002 was specifically stated to be **261 ppt** (parts per trillion).

6. **Final Answer**:
- Therefore, the concentration of CFCs in 2002 was **261 ppt**.