Depending on emission levels, up to 95% of today’s ocean climates could vanish by 2100, replaced by hotter, more acidic waters. This poses a severe threat to marine life that depends on current conditions.
Between 35.6% and 95% of 20th century ocean surface climates — defined by surface water temperature, pH, and the concentration of the mineral aragonite — may disappear by 2100, depending on how greenhouse gas emissions develop in the first half of the 21st century, according to a study published in Scientific Reports. The findings also suggest that between 10.3% and 82% of the global ocean may experience surface climates that have not existed before.
Katie Lotterhos and colleagues modeled ocean climates globally for three time periods: the early 19th century (1795–1834), the late 20th century (1965–2004), and the late 21st century (2065–2104). The authors compared these modeled climates across various locations using two emission scenarios, RCP 4.5 and RCP 8.5. Under these scenarios the volume of greenhouse gases emitted during the 21st century either peaks in 2050 followed by a slowed increase, or peaks in 2100 followed by a slowed increase, respectively.
Through their comparisons, the authors were able to show which ocean climates from the 19th and 20th centuries may no longer be found in the 21st century (disappearance), and climates that may emerge in the 21st century which did not exist in the 18th and 20th centuries (novel climates). The authors showed that while ocean climates did not change significantly between the 19th and 20th centuries, by 2100, 10% to 82% of the ocean surface may experience new climates with higher temperatures, more acidic pH, and lower saturation of aragonite. Aragonite is a mineral that corals and other marine organisms use to form shells. Under the RCP 4.5 scenario, 35.6% of surface ocean climates may disappear by 2100, which rises to up to 95% under the RCP 8.5 scenario.
The authors conclude that while some marine species currently keep pace with changing ocean climates by dispersing to new habitats, this may no longer be possible if existing ocean climates disappear, forcing species to either adapt rapidly to new climates or disappear.
Reference: “Novel and disappearing climates in the global surface ocean from 1800 to 2100” by Katie E. Lotterhos, Áki J. Láruson and Li-Qing Jiang, 26 August 2021, Scientific Reports.
DOI: 10.1038/s41598-021-94872-4
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4 Comments
While RCP 8.5 has been called “Business As Usual,” more than one researcher has demonstrated that it is highly improbable, based on the reserves of fossil fuels.
“MORE acidic pH” is an oxymoron. For a state of being to increase in abundance, it has to first exist. The phrase is logically and grammatically similar to talking about a man becoming “more pregnant.” Aqueous solutions can have three states: alkaline, neutral, or acidic. The oceans are alkaline, and probably always will be. It is improbable that the bulk ocean pH will ever even be neutral, let alone acidic. (Except locally, like around Black Smokers.) “Ocean Acidification” is a gross misappropriation of a term derived from chemistry.
“…, and lower saturation of aragonite. Aragonite is a mineral that corals and other marine organisms use to form shells.”
The Aragonite Compensation Depth (ACD) is basically the depth at which aragonite becomes unstable and dissolves readily. It is determined principally by temperature and pH. However, the article implies that calcifiers use the mineral aragonite as ‘building blocks’ in their shells. They actually expend energy to change the pH at the growth edge of their shells, and create aragonite or calcite from the dissolved bicarbonate. Once grown, the organisms usually cover the mineral growth with mucous, chitin, or both, to resist corrosion. When they die, the bare mineral is then subject to dissolution at the ACD.
“…, 35.6% of surface ocean climates MAY disappear by 2100, ,,,” It has been said that the universal language of science is mathematics. What is the probability of “may,” and what are the error bars associated with the estimate?
There are good reasons to believe that there are emergent phenomena in the tropics that serve as negative feedback loops, stabilizing the temperatures. That is to say, there may be little need for tropical organisms to migrate because they have adapted to one of the more stable climates. It is more likely that they will just expand their territory into the mid-latitudes.
All modeling should be verified by empirical data obtained in the field. Unfortunately, it seems that far too many young academics have grown up with video games and accept, unquestionably, the results of computer program outputs.
Were in not for COP-26 scheduled for November, we would probably be spared such shoddy ‘scholarship’ as this article!
“Were it not for COP-26 …”
“Between 35.6% and 95% of 20th century ocean surface climates…”
Pretty rich, considering data on 20th century “surface climates” is pretty sparse up to 1979 or so.
And you gotta love it when a computer guesstimate is given to a decimal place. Makes it so much more credible, doncha think?
Shame on this website for giving this silly study such prominent play.
Amazing how you debunk yourselves:
“Up to 95% of Ocean Surface Climates May Disappear by 2100 Due to Climate Change”
“Through their comparisons, the authors were able to show which ocean climates from the 19th and 20th centuries may no longer be found in the 21st century (disappearance), and climates that may emerge in the 21st century which did not exist in the 18th and 20th centuries (novel climates).”
Peak science right here.