Consider statements about environment: 1. The greenhouse effect is entirely unnatural. 2. Deforestation contributes to global warming. 3. Ozone depletion causes skin cancer. Which are correct? MCQ with Answer and Explanation

The greenhouse effect is a natural process that keeps Earth warm; the problem is the enhanced greenhouse effect due to human activities. Deforestation reduces the number of trees absorbing CO2, increasing atmospheric greenhouse gases and contributing to global warming. Ozone layer depletion allows more harmful UV-B radiation to reach Earth, significantly increasing the risk of skin cancers. Thus, statements 2 and 3 are correct.