Consider statements about environment: 1. The ozone layer is in the stratosphere. 2. CFCs deplete the ozone layer. 3. Global warming is caused by a decrease in CO2. Which are correct? MCQ with Answer and Explanation

The ozone layer, a region of high ozone concentration, is located in the stratosphere, approximately 15 to 35 kilometers above Earth's surface, where it absorbs harmful UV radiation. Chlorofluorocarbons (CFCs), once widely used in refrigerants and aerosols, release chlorine atoms in the stratosphere that catalytically destroy ozone molecules, leading to ozone depletion. Global warming is primarily caused by an increase, not a decrease, in atmospheric greenhouse gases like carbon dioxide (CO2), which trap more heat. Thus, statements 1 and 2 are correct.