As much as 95% of the ocean floor local weather may disappear by the yr 2100 – watts with that?
Depending on the development of greenhouse gas emissions in the first half of the 21st to a study published in Scientific Reports. The results also suggest that between 10.3% and 82% of the global oceans may have a surface climate that has never existed before.
Katie Lotterhos and colleagues modeled the world’s ocean climate 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 at different locations using two emission scenarios, RCP 4.5 and RCP 8.5. Under these scenarios, the amount of greenhouse gases emitted in the 21st century will either peak in 2050, followed by a slowed increase, or a peak in 2100, followed by a slowed increase.
Through their comparisons, the authors were able to show which ocean climates from the 19th and 20th centuries will be used in the 21st century (novel climates). The authors showed that the marine climate did not change significantly between the 19th and 20th centuries, but by 2100 10 to 82% of the sea surface could experience a new climate with higher temperatures, more acidic pH values and lower aragonite saturation. Aragonite is a mineral that corals and other marine organisms use to form clams. In the RCP 4.5 scenario, 35.6% of the surface ocean climate could disappear by 2100, which increases to up to 95% in the RCP 8.5 scenario.
The authors conclude that while some marine species are currently keeping up with the changing marine climate by spreading into new habitats, this may no longer be possible if the existing marine climate disappears, forcing the species to either quickly adapt to new climates or disappear.
New and disappearing climates in the global surface ocean from 1800 to 2100
DOI: 10.1038 / s41598-021-94872-4
The paper at Nature.
Marine ecosystems are experiencing unprecedented warming and acidification from anthropogenic carbon dioxide. For the global ocean surface, we quantified the extent to which the current climate disappears and new climates (with no newer analogues) emerge, from 1800 through various emission scenarios through 2100. We quantified the ocean surface environment based on model estimates of carbonate chemistry and temperature. It has been estimated that no grid points on the ocean surface experienced an extreme degree of global disappearance or novelty between 1800 and 2000. In other words, the majority of environmental changes since 1800 have not been new, which is consistent with evidence that marine species have been able to track changing environments through diffusion. However, between 2000 and 2100, according to the Representative Concentration Path (RCP) projections 4.5 and 8.5, it is estimated that 10–82% of the surface ocean will experience an extreme degree of global novelty. In addition, it is estimated that 35–95% of the surface ocean is experiencing extreme levels of global disappearance. These upward estimates of the novelty and disappearance of climate are larger than those predicted for terrestrial systems. Without attenuation, many species will face rapid disappearance or novel climates that cannot be overtaken by spread and may require evolutionary adaptation to keep up.