The undersea volcano, located in the South Pacific island nation of Tonga, violently erupted from 14 to 15 January 2022. The Tonga volcano eruption has aroused extensive discussion in the climate change field. Some climatologists believe that this event will cause little effect on global climate change while others insist that it will trigger “the year without a summer” as the Tambora eruption did in 1815. How will the Tonga volcano eruption affect global climate change? Based on the indices of past volcanic eruptions and the eruption data of El Chichón volcano in 1982, we use a simplified radiation equilibrium model to quantify the stratospheric aerosol radiative forcing and the change in global mean surface air temperature (Ts) caused by the Tonga volcano eruption. The results show that the global aver- age Ts will decrease by about 0.0315–0.1118℃ in the next 1–2 years. The Tonga eruption will slightly slow down the global warming in a short period of time, but it will not change the global warming trend in the long term. In addi- tion, we propose a generalized approach for estimating the impact of future volcanic eruption on global mean Ts.