On 16 May 2025, the Supreme Court invalidated the Indian Government's orders passed in which years, allowing ex-post facto environmental clearances?

The correct option is 2017 and 2021.

Step-by-Step Explanation:

1. Context of Ex-Post Facto Environmental Clearances:
Ex-post facto environmental clearances refer to permissions granted to industrial or development projects after they have already commenced operations without obtaining prior mandatory environmental clearances. Environmental activists and legal experts have consistently argued that granting retrospective clearances violates the Precautionary Principle and the Sustainable Development Principle under environmental jurisprudence.

2. Supreme Court Ruling:
On 16 May 2025, the Supreme Court of India delivered a landmark judgment invalidating the notifications/office memorandums issued by the Union Ministry of Environment, Forest and Climate Change (MoEFCC) in the years 2017 and 2021. These office memorandums had laid down a mechanism for granting ex-post facto environmental clearances to entities operating illegally without prior approval.

3. Conclusion:
The Supreme Court reaffirmed that prior environmental clearance is a mandatory legal requirement under the Environment (Protection) Act, 1986, thereby setting aside the executive orders issued in 2017 and 2021.