Simulated Effects of U.S. Withdrawal from Paris Agreement under Four Scenarios

Under the Paris Agreement framework, many developing countries call for low-carbon technology transfers from developed countries as a critical element in the global partnership for carbon emissions abatement. Such a partnership may be disrupted as the U.S. walks away from the agreement. Based on CIECIA-TD model, this paper examines effects of the U.S. exit on global low-carbon technology transfers under various scenarios and simulates the effects on low-carbon technology transfer, climate change, countries' emissions abatement results, and economic development. Our findings suggest that lowcarbon technology has significant emissions abatement and temperature rise mitigation effects. Low-carbon technology transfer among developed countries offers huge emissions abatement potentials, but patent protection system presents a significant barrier to further carbon emissions abatement. In this sense, the U.S. exit from the Paris Agreement will significantly impede developed countries' carbon emissions abatement through technology transfer. With limited knowhow, R&D and learning capacity, developing countries will suffer more to cut carbon emissions under the chain effects of a more challenging technology sharing environment that may result from the U.S. exit from the Paris Agreement. As a gradualist emissions abatement approach, low-carbon technology transfer cannot reduce emissions substantially within a short time, but its climate welfare is conducive to global economic growth and of great significance to carbon governance.