Due to the uncertainty associated with the transition from global warming target to national commitments on emissions reduction,this study analyses the impacts on national carbon quotas with various emission pathways,baseline scenarios,and allocation schemes and parameters associated with these schemes,which is based on the emissions capacity as a result of the global warming target of two-degree temperature increase identified in the Fifth Assessment Report (AR5) of IPCC.The results indicated that: 1) various schemes for quota allocation resulted in higher uncertainty for developed countries than developing countries,and the uncertainty was even higher for countries that have greater differences between their current emissions and the global average; 2) within the same allocation scheme,quota allocation varied from the selection of key parameters,such as,convergence time,starting year for historical responsibility and participation threshold,and developing countries would obtain greater carbon quotas with earlier starting year for responsibility and higher participation threshold; 3) The global carbon allowable capacity had a great impact on each countrys carbon permits,and with the increase of global capacity,it would result in a larger increase in quotas for developed countries than developing countries; 4) The uncertainty in quota allocation brought by the differences in baseline scenarios is relatively low under most allocation schemes,expect those schemes with thresholds.Despite of the uncertainties,it is certain that future emissions spaces for all countries including China are limited under the global warming target of two-degree temperature increase.We should conduct long-term planning on low-carbon development,develop low-carbon technologies,and invest on related research concurrently.