The profound climatic and environmental changes projected for the Arctic region by 2100  are also anticipated to alter the composition of apex assemblages like marine mammals . Under both RCP2.6 and 8.5 scenarios the most vulnerable marine mammal species will be the North Pacific right whale  and the grey whale . The extinction of the most-vulnerable species will disproportionately eliminate unique and important evolutionary lineages as well as functional diversity, with consequent impacts throughout the entire marine ecosystem . More generally, future warming and acidification simulated in mesocosm experiments support projections of a substantial increase in biomass and productivity of primary producers and secondary consumers, but a decrease by >40% of primary consumers . On longer time scales, alteration of energy flow through marine food webs may lead to ecological tipping points  after which the food web collapses into shorter, bottom-heavy trophic pyramids .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report