Carbon emission reduction and climate governance through international low-carbon technology sharing

[Objective] International low-carbon technology sharing is an important pathway to achieve global carbon neutrality. Comprehensively evaluating the carbon reduction potential of international low-carbon technology sharing, as well as its effects on reducing carbon neutrality costs, mitigating climate change, and promoting technological progress, holds significant theoretical and policy implications for future global climate cooperation. [Methods] This study constructed a climate-economy-technology integrated assessment model, CIECIA-GT, to comprehensively evaluate the carbon emission reduction potential of international low-carbon technology sharing policies and their climate governance effectiveness under the constraint of carbon neutrality from 2025 to 2100. [Results] (1) The global surface temperature rise in 2100 will decrease significantly as the degree of low-carbon technology sharing increases. Under the scenario of complete technology sharing, it can be controlled within 2.62°C. (2) Under the scenario of complete technology sharing, developed economies will fully acquire low-carbon technology transfer due to their superior learning capabilities. In contrast, developing economies will be constrained by their own technological innovation and learning capabilities, leading to limited improvements in their technology levels. (3) The implementation of international low-carbon technology sharing policies can help countries reduce their reliance on carbon cap measures under the constraint of carbon neutrality, and increase cumulative economic utility significantly, and control their carbon neutrality costs. (4) Additional technological support from developed economies can effectively accelerate technological imitation in developing economies and further reduce carbon neutrality costs, but the marginal effect will be limited. [Conclusion] International low-carbon technology sharing holds significant potential for technological advancement and carbon emission reduction, but it cannot directly achieve climate change mitigation goals. Reducing patent protection duration can promote the participation of developed economies in international low-carbon technology transfer, and is more effective in mitigating climate change than reducing patent breadth. International low-carbon technology sharing can significantly reduce carbon neutrality costs, and additional technological support from developed economies to developing economies can further enhance the feasibility and equity of global carbon neutrality pathways, and therefore is of clear significance to climate governance. Combining low-carbon technology sharing with other high-cost emission reduction measures is a reasonable design approach for international carbon emission reduction cooperation.