The rising global population is forcing the need for adapting alternative sustainable technologies for enhancedcrop productivity. The CO2 Concentration Mechanisms (CCMs) evolved in algae to counter the inefficient CO2fixing enzyme, RuBisCo and slower diffusion of CO2 in water offers good scope for the above purpose. TheCCMs are single-celled CO2 supply mechanisms that depend on multiple CO2/HCO3

- transporters andacclimation states and accumulate 100-fold more CO2 than low CO2 environments. Although some insightshave been obtained regarding the CCMs of blue-green algae and green algae like Chlamydomonas reinhardtii,further progress needs to take place to understand the molecular and biochemical basis for intracellulartransport of CO2. In this review, complete information pertaining to the core CCM is presented and discussedin light of the available literature. In addition to this, information on CO2/HCO3

- sensing, photo-acclimation inlow CO2, liquid-like nature of pyrenoid, untapped potential of high CO2 responses and high CO2 requiringmutants, and prospects of engineering CCM components into higher plants are presented and discussed.