In recent decades, anthropogenically-driven climate change has affected phytoplankton growth and has widened the differences observed among the gross primary productivity of waterbodies (WGPP) in global lake systems. Results from this study showed that the range of WGPP increased over time (from 1950 to 2020). However, the median WGPP of global inland lake systems has gradually and significantly decreased. On a geographical scale, the geographical distribution WGPP pattern was high in low- to mid-latitudinal regions and low in highlatitudinal regions. This study found that chrysophytes mainly control WGPP in high-latitudinal regions while diatoms, cyanobacteria, and chlorophytes are dominant in low-latitudinal regions. Additionally, dominant and sub-dominant phytoplankton communities contribute the most to WGPP. Under extreme environmental conditions, algae must strengthen its capacity to adapt to the burgeoning environmental conditions of global lake systems while gradually evolving to survive. Accordingly, regulating environmental conditions to promote phytoplankton community diversity and to accelerate community competition will play an important role in maintaining the ecological balance, environmental health and carbon cycle of global lake systems.