Anthropogenic influence of temperature changes across East Asia using CMIP6 simulations

Area of Science:

• Climate Science
• Atmospheric Science
• Environmental Science

Background:

• Surface air temperatures (SATs) in East Asia (EA) are influenced by various natural and anthropogenic factors.
• Understanding the specific impact of human activities on regional climate is crucial for future projections.

Purpose of the Study:

• To investigate the impact of anthropogenic forcings (ANT) on East Asian surface air temperatures (SATs) from 1850 to 2014.
• To analyze historical SAT changes and future projections using Coupled Model Intercomparison Project Phase 6 (CMIP6) datasets.
• To differentiate the influence of greenhouse gas (GHG) emissions from other forcings.

Main Methods:

• Utilized CMIP6 multi-model ensemble simulations for historical and future climate projections.
• Applied the optimal fingerprinting method to detect and attribute climate change signals.
• Conducted two-signal and three-signal analyses to separate the effects of different forcings (ANT, NAT, GHG, AER).

Main Results:

• From 1850-2014, combined forcings (ALL = ANT + NAT) increased EA SAT by 0.031 °C/decade, with greenhouse gas (GHG) emissions alone causing a 0.08 °C/decade increase.
• Following 1969, ANT forcing accelerated SAT increases, with GHG and ALL forcings showing enhanced rates of 0.268 °C/decade and 0.255 °C/decade, respectively.
• Optimal fingerprinting confirmed that ANT forcing distinctly influences EA climate change, with GHG emissions identified as the dominant driver, separable from aerosol (AER) and natural (NAT) forcings.

Conclusions:

• Human-induced greenhouse gas emissions are the primary drivers of observed and projected surface air temperature warming in East Asia.
• Anthropogenic forcings have had a detectable and significant impact on the regional climate of East Asia.
• Future climate projections indicate continued substantial warming trends in East Asia driven by socioeconomic pathway emission scenarios.