In recent decades, many lakes in the northern hemisphere have faced the problem increased browning. To study the impact of future browning on Bolmen Lake, a mesocosm study was set up to simulate future browning scenarios of the Bolmen Lake (in the 50 years and 100 years) and study its effects on abiotic parameters and biological parameters. The results show that the increased browning will reduce the pH, dissolved oxygen (DO), and photosynthetically active radiation (PAR) of Lake Bolmen but will increase the phosphate concentration and chlorophyll a concentration in the water. These results indicate that as browning further increases, the lake will shift to heterotrophic dominated food web, which may influence the future dissolved oxygen level and adversely affect fish production.