Effects of rate and timing of short-lived climate forcer mitigation on cumulative warming and temperature targets

radiative forcing;climate change;air pollution;climate forcer;carbon dioxide;black carbon;short-lived climate forcer;short-lived climate pollutant;cumulative temperature perturbation;global mean temperature

Hade, Kevin Paul Michael ; Bond ; Tami C.

关键词: radiative forcing;    climate change;    air pollution;    climate forcer;    carbon dioxide;    black carbon;    short-lived climate forcer;    short-lived climate pollutant;    cumulative temperature perturbation;    global mean temperature;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/92982/HADE-THESIS-2016.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Short lived climate forcers (SLCF) such as black carbon, tropospheric ozone, or methane have been proposed as complements to mitigating greenhouse gases such as CO2. I investigated the possible importance of SLCF mitigation rates and timing under a variety of CO2 emission trajectories. I built a simple model that takes emission trajectories of CO2 and black carbon as input and calculates radiative forcing and global mean temperature change. Impulse response functions were used to calculate the concentration of carbon dioxide in the atmosphere and the global mean temperature change. The resulting temperature change was used to evaluate the effects of SLCF mitigation on reducing peak temperature or delaying the onset of temperature thresholds. I also calculated an integrated temperature response referred to as a cumulative temperature perturbation (CTP). For measures of peak or target temperatures, I found that there is little benefit to mitigating SLCF early or at rapid rates except under low CO2 emission trajectories such as RCP-2.6. Recent publications have questioned the importance of mitigating SLCF in the near term because of their limited impact on peak temperature compared to CO2. However, these studies do not acknowledge the path dependence of cumulative climate impacts and ignore potential welfare gains that could result from reducing SLCF in the near term. With respect to cumulative impacts, the rate and timing of SLCF mitigation matter especially in the first three generations where 50-100% or more of the CTP difference between RCP-8.5 CO2 and RCP-6 CO2 can be achieved by mitigating SLCF over 40 years or less and beginning mitigation before 2035. These mitigation rates are consistent with projections for global on-road transportation emissions.