It is a focus of climate protection to stabilize CO2 concentration within 500ml/m3 by 2050 and to lower the global temperature 2℃ by 2100. This paper expands the RICE model for global climate-change strategies to include GDP spillover mechanism and technological progress, assessing the equity and effectiveness of the global emission quota allocation among countries. The emission target of our model is stabilizing CO2 concentration within 500ml/m3 by 2050. The results show the disparity of remaining emission quotas between developed and developing countries will be too great to be accepted in global quota allocation negotiation while historical emissions are counted from 1861 with the concept of equal emission right per capita. Reaching the 2℃ target for EU countries, the Stern climate strategy would make developing countries afford relatively more to reduce emission. A comparatively equitable and efficient strategy is that developed countries should take immediate action and commit to cutting emission by 80% of 1990 levels by 2050; China and Russia start to reduce emission from 2020, and cut emission by 25%, 30% of 2005 levels respectively by 2050; and the rest of the world start to reduce from 2020 and the increased emission should be no more than 30% of 2005 levels.