What major global event does C40 participate in for climate discussions?

C40 participates in the Conference of the Parties (COP), which is a significant global forum for discussing climate policy and action. This event is organized under the United Nations Framework Convention on Climate Change (UNFCCC) and brings together nations, policymakers, scientists, and activists to negotiate and address climate change issues.

COP events facilitate vital discussions surrounding commitments to reduce greenhouse gas emissions, share best practices, and advance international cooperation on climate actions. C40, as a network of cities, leverages its presence at COP to influence climate-related strategies and advocate for urban initiatives that contribute to global emissions reductions and sustainable urban development.

The other options, while relevant to global discussions, do not specifically encapsulate the formal and structured international negotiations that occur at COP, making it the most fitting answer for the context of C40's participation in global climate discussions.