How to establish a global climate coalition with broad participation, stability, and significant abatement effect has been an urgent issue for the international community.This paper divides the climate coalition models into the externality effect, timing effect, and cost effect ones.The equilibrium results of noncooperation, full cooperation, a two stages static game of Cournot coalition, and a three stages dynamic game of Stackelberg coalition are compared under symmetric and asymmetric conditions. The stable coalition sizes are determined by simulation. It is found that the positive effect of externality effect and the negative effect of timing effect would offset or dominate each other under certain conditions within the coalition. When the costbenefit ratio is close to 0, the net benefit of the coalition is small, with the timing effect becoming dominant. Leaders will reduce abatement and induce followers to increase abatement. This will attract more participants and form a stable grand coalition eventually, which explains the “cooperation paradox”. The cost effect stems from asymmetry among countries, which makes the externality effect no longer strictly positive and creating the need for payment transfers. For countries with high benefits and low costs, the timing effect is the greatest. For countries with high benefits and high costs, the cost effect is the greatest. The simulation results show that when costs and benefits present a skewness distribution with negative covariance, the more pronounced the asymmetry, the more stable and effective the abatement effects of coalitions.