Yes, case studies can be used to analyze the complexities of global environmental governance, climate change negotiations, and the role of states, corporations, and civil society in addressing environmental challenges in the field of Political Science and International Relations (PSIR).

Why Case Studies?
Case studies provide a comprehensive and detailed analysis of specific instances or events, allowing researchers to examine the complexities and nuances of the subject matter. In the context of global environmental governance, climate change negotiations, and the role of different actors, case studies can offer valuable insights and understanding.

Complexities of Global Environmental Governance:
Case studies can help analyze the complexities involved in global environmental governance by examining real-life instances. This can include studying the challenges faced in implementing multilateral environmental agreements, exploring the dynamics between different international organizations and state actors, and understanding the power dynamics at play in decision-making processes.

Climate Change Negotiations:
Case studies can shed light on the intricacies of climate change negotiations by examining specific instances such as the Kyoto Protocol or the Paris Agreement. Through detailed analysis, researchers can explore the role of different actors, including states, corporations, and civil society organizations, in shaping the negotiation process. Case studies can also reveal the challenges faced in reaching consensus, the influence of power dynamics, and the effectiveness of different strategies employed.

Role of States, Corporations, and Civil Society:
Case studies can be used to analyze the role of states, corporations, and civil society in addressing environmental challenges. By examining specific instances, researchers can assess the actions and initiatives taken by these actors to mitigate environmental issues. Case studies can also highlight the different approaches adopted by states, the influence of corporate interests, and the impact of civil society mobilization.

Conclusion:
In the field of PSIR, case studies can provide valuable insights into the complexities of global environmental governance, climate change negotiations, and the role of states, corporations, and civil society. By analyzing specific instances, researchers can gain a deeper understanding of these issues and draw lessons for future policy-making and action.