Explanation:

• Statement 1 is correct. The CBAM is a policy introduced by the European Union to impose a tax on the carbon emissions embedded in certain imported goods. It ensures that imports are subject to the same carbon costs as domestic products under the EU's Emissions Trading System (ETS). 

• Statements 2 and 3 are incorrect. CBAM currently applies only to specific carbon-intensive sectors such as cement, iron and steel, aluminium, fertilizers, electricity, and hydrogen. Carbon leakage refers to the situation where businesses move production to countries with less stringent climate policies, leading to an overall increase in global emissions.

Hence option 1st is correct.