Characterization of spatial and temporal variations of CO2 concentration on tropical Island and analysis of influencing factors

In this study, the spatial and temporal variations and distribution characteristics of the carbon dioxide (CO₂) concentration on Hainan Island are analyzed using GOSAT L3 data from 2011 to 2024, and the effects of various factors impacting the CO₂ concentration on Hainan Island are discussed. The results indicate that from 2011 to 2024, the CO₂ concentration on Hainan Island showed an increasing trend, with a fast growth rate in the early period and a slow growth rate in recent years with the implementation of the dual-carbon strategy. The spatial distribution is affected by anthropogenic activities, topography, vegetation and solar radiation, and the overall CO₂ concentration pattern is high in the north and low in the south. Human activities are the most important source of carbon on Hainan Island, vegetation is the most important carbon sink, and elements such as surface temperature, precipitation, and total solar radiation play roles in suppressing CO₂. The CO₂ concentration on Hainan Island is expected to continue to increase at a slow rate and may display a decreasing trend in the future.