Climate change and China's coastal zones and seas: Impacts, risks, and adaptation

Abstract

This article provides an assessment of the changes in marine climate drivers (hazards), associated impacts, risks, and adaptation to the coastal China zones and seas since the mid 20th century. The results show that: ① Marine climate drivers,such as ocean warming,sea level rise, typhoon, storm surges and marine heat waves (MHWs),have increased significantly in strength,frequency and range over the past decades. ② Ocean warming has caused substantial changes in marine phenology,species composition,geographical distribution, and frequent occurrences of ecological disasters such as red tides,green tides,and macro-jellyfish outbreaks,while MHWs have induced degradation in tropical coral reefs and major losses in the marine aquaculture industry in the coastal China seas. ③ Sea level rise threatens the typical habitats of coastal wetlands such as mangrove and estuaries,and exacerbates coastal erosion,seawater intrusion and the impacts of typhoon, storm surges on the coastal flood disasters. ④ Human activities,such as large-scale reclamation,pollutant discharge, and overfishing, have increased the exposure and vulnerability of China's marine and coastal ecosystems, leading to the low-aging and miniaturization of fishery types,decline of offshore fishery resources, reduction of coastal wetland areas,and degradation of biodiversity and ecosystem stability. ⑤ Under different climate scenarios such as low and high greenhouse gases emission scenario (RCP 2.6 and 8.5), as the warming and sea level rise in the coastal China seas continue,extreme sea level (ESL) events will occur more frequently, e.g., by the end of this century, the current once per century ESL events will become annually or even annually less (RCP 8.5) in many coastal areas,such as at Lvsi and Xiamen tidal gauge stations; and the ESL events could pose serious risks on the coastal areas. Finally, the article further discusses the adaptation measures and related uncertain issues to address climate change in the coastal China zones and seas,and puts forward relevant countermeasures and suggestions in order to reduce its negative impacts on the sustainable development of human community.