A new study states that the effects of climate change on the world’s seas might be felt for thousands of years.
Researchers from the University of California analyzed the Pacific Ocean seafloor sediment core and concluded that marine ecosystems can take thousands of years to recover from climate-related upheavals.
The researchers studied thousands of invertebrate fossils to prove that ecosystem recovery from climate change and seawater deoxygenation might take place on a millennial scale. They used a 30 foot-long core sample of the Pacific Ocean seafloor. They emphasized the importance of using a large sample from one portion of the seafloor. The team cut the region like a cake to analyze the full, unbroken record. The study involved 5,400 invertebrate fossils within a sediment core from offshore Santa Barbara, California.
They found that historically ecosystems are affected by dramatic shifts in climate. The slice of ocean life (called tube-like sediment core) existed between 3,400 and 16,100 years ago.
The researchers found from their gathered data that layers of abundant, diverse, and well-oxygenated seafloor ecosystems were followed by a period of oxygen loss and warming with accompanied rapid loss of biodiversity. In periods of lesser than 100 years, oceanic oxygen levels decreased between 0.5 and 1.5 mL/L.
They also found that the corresponding sediment samples showed relatively minor oxygen fluctuations, which resulted in dramatic changes for seafloor communities.
Sarah Moffitt, PhD, researcher from the UC Davis Bodega Marine Laboratory and Coastal and Marine Sciences Institute, and the lead author of the study, said, “These past events show us how sensitive ecosystems are to changes in Earth’s climate – it commits us to thousands of years of recovery. It shows us what we’re doing now is a long-term shift – there’s not a recovery we have to look forward to in my lifetime or my grandchildren’s lifetime.”
The researchers believe that these past events show us that the present damages, which climate change is causing to the oceans, could take thousands of years to repair.
The findings were published in the PNAS journal.