Kun Zhang, a Ph.D. candidate from the CEEP-BIT went to the State University of New York at Binghamton for joint training in November 2018. His supervisor is Professor Zili Yang, at the Department of Economics, the State University of New York at Binghamton. Professor Yang is mainly engaged in research work in resource and environmental economics, and participated in the development and establishment of the RICE model, the most influential integrated assessment model of climate change in the world. The State University of New York at Binghamton was founded in 1946. It is a first-level national university in the United States, a "public Ivy League" university, and one of the four flagship universities of the State University of New York system. 

　　Kun Zhang mainly conducts research on emission reduction cooperation in response to climate change. Climate change is a typical public good with negative externalities, and the climate damage caused by greenhouse gas emissions in a single region is shared by countries all over the world. Therefore, coordinated global cooperation to reduce emissions is the most effective way to solve the problem of climate change. In addition, the different ways of cooperating in emission reduction among various regions in the world will also have different effects on the economic development, energy demand, and carbon emissions of various regions. Under the guidance of Professor Yang, Kun Zhang has constructed the RICE-China model, keeping other regions unchanged on the basis of the RICE model, refined China’s modeling structure, introduced energy into China’s production function, and consider different types of energy. Based on the RICE-China model, he has analyzes the impact of different ways of cooperation between regions on China's future energy demand and economic impacts. 

　　In addition, in the integrated assessment model of climate change, the uncertainty estimation of climate damage has always attracted much attention. During the visiting period, Kun Zhang also participated in another study on climate damage estimation. By introducing Professor Weitzman's fat-tail hypothesis into the estimation of climate damage, Kun and his collaborator have discussed the influence of the climate change risk with small probability but a huge impact on the estimation of climate damage. During the visiting study, through academic cooperation and exchanges, Kun Zhang further learned about the integrated assessment modeling knowledge of climate change, which laid a good foundation for him to promote the modeling research on the cooperation issue of emission reduction and also enriched research ideas.