Projected impacts of global warming scenarios on marine ecosystems: Insights from the CMIP6 model

Rising oceanic temperatures and increased heat content have triggered a decline in marine biodiversity and the degradation of ecosystem services. This study employs the Coupled Model Intercomparison Project Phase 6 (CMIP6) to analyze variables within the Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) framework. Focusing on two contrasting Shared Socioeconomic Pathways (SSPs) - SSP1-2.6 (low-warming scenario) and SSP5-8.5 (high-warming scenario) - we assess future impacts of climate-related factors on marine ecosystems across major oceanic regions. Under the high-warming SSP5-8.5 scenario, global ocean temperature rise, coupled with declining surface pH levels, nitrate concentrations, and plankton biomass/productivity, is evident. Regional reductions in plankton biomass/productivity, especially pronounced at higher latitudes, are observed in both SSP scenarios. Nutrient cycling emerges as a pivotal factor influencing plankton communities, particularly ammonium regulation in the Southern Ocean. This research emphasizes the urgent need to curb greenhouse gas emissions to mitigate global warmings profound effects on marine ecosystems.