For the UPSC examinations, candidates should focus on crucial environmental issues such as climate change, biodiversity loss, and pollution. Understanding the implications of global warming, the impact of deforestation, and sustainable development goals are also vital. Awareness of India's national policies related to the environment, as well as international agreements like the Paris Agreement, is crucial. Furthermore, issues like water scarcity, waste management, and renewable energy should also be prioritized, as they often make their way into both the prelims and mains examinations.