title: Biotic and human vulnerability to projected changes in ocean biogeochemistry over the 21st century.
abstract: Ongoing greenhouse gas emissions can modify climate processes and induce shifts in ocean temperature, pH, oxygen concentration, and productivity, which in turn could alter biological and social systems. Here, we provide a synoptic global assessment of the simultaneous changes in future ocean biogeochemical variables over marine biota and their broader implications for people. We analyzed modern Earth System Models forced by greenhouse gas concentration pathways until 2100 and showed that the entire world's ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. In contrast, only a small fraction of the world's ocean surface, mostly in polar regions, will experience increased oxygenation and productivity, while almost nowhere will there be ocean cooling or pH elevation. We compiled the global distribution of 32 marine habitats and biodiversity hotspots and found that they would all experience simultaneous exposure to changes in multiple biogeochemical variables. This superposition highlights the high risk for synergistic ecosystem responses, the suite of physiological adaptations needed to cope with future climate change, and the potential for reorganization of global biodiversity patterns. If co-occurring biogeochemical changes influence the delivery of ocean goods and services, then they could also have a considerable effect on human welfare. Approximately 470 to 870 million of the poorest people in the world rely heavily on the ocean for food, jobs, and revenues and live in countries that will be most affected by simultaneous changes in ocean biogeochemistry. These results highlight the high risk of degradation of marine ecosystems and associated human hardship expected in a future following current trends in anthropogenic greenhouse gas emissions.
authors.affiliation: Department of Geography, University of Hawaii, Honolulu, Hawaii, United States of America.
authors.forename: Camilo
authors.initials: C
authors.lastname: Mora
authors.forename: Chih-Lin
authors.initials: CL
authors.lastname: Wei
authors.forename: Audrey
authors.initials: A
authors.lastname: Rollo
authors.forename: Teresa
authors.initials: T
authors.lastname: Amaro
authors.forename: Amy R
authors.initials: AR
authors.lastname: Baco
authors.forename: David
authors.initials: D
authors.lastname: Billett
authors.forename: Laurent
authors.initials: L
authors.lastname: Bopp
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Mark
authors.initials: M
authors.lastname: Collier
authors.forename: Roberto
authors.initials: R
authors.lastname: Danovaro
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Gooday
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Grupe
authors.forename: Paul R
authors.initials: PR
authors.lastname: Halloran
authors.forename: Jeroen
authors.initials: J
authors.lastname: Ingels
authors.forename: Daniel O B
authors.initials: DO
authors.lastname: Jones
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Levin
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Nakano
authors.forename: Karl
authors.initials: K
authors.lastname: Norling
authors.forename: Eva
authors.initials: E
authors.lastname: Ramirez-Llodra
authors.forename: Michael
authors.initials: M
authors.lastname: Rex
authors.forename: Henry A
authors.initials: HA
authors.lastname: Ruhl
authors.forename: Craig R
authors.initials: CR
authors.lastname: Smith
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Sweetman
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Thurber
authors.forename: Jerry F
authors.initials: JF
authors.lastname: Tjiputra
authors.forename: Paolo
authors.initials: P
authors.lastname: Usseglio
authors.forename: Les
authors.initials: L
authors.lastname: Watling
authors.forename: Tongwen
authors.initials: T
authors.lastname: Wu
authors.forename: Moriaki
authors.initials: M
authors.lastname: Yasuhara
mesh_terms: D044822:Biodiversity; D018534:Earth, Planet; D017753:Ecosystem; D055593:Geological Phenomena; D006802:Human Activities; D006801:Humans; D009792:Oceans and Seas; D012623:Seawater; D013997:Time Factors