Earth’s oceans which have suffered greatly due to climate change are not likely to recover quickly. A recent research, led by Sarah Moffitt, a scientist with the University of California at Davis Bodega Marine Laboratory and Coastal and Marine Sciences Institute, has revealed that in order to recover from the effects of rapid climate change, Earth’s oceans may take not only hundreds but thousands of years. The study, published online in the journal PNAS, is the first to examine fossil records for evidence of distress and recovery of seafloor ecosystems in response to sudden and rapid climate change.
More than 5,400 invertebrate fossils, extracted from a sediment core taken from offshore Santa Barbara in California, have been analyzed by the researchers. The sediment core belongs to a period between 3,400 to 16,100 years ago and provides an idea about what happened before and after the last major deglaciation. The last major deglaciation led to a rapidly warming climate with rising sea levels due to melting of polar ice caps. It also resulted in an increase in areas of low oxygen in the oceans. As a result, a transition occurred from an environment of flourishing and diverse ocean ecosystems to a sharp decline in biodiversity.
According to Moffitt and her team, although the changes in sea floor ecosystems occurred rapidly due to climate change and the corresponding deoxygenation of sea water, recovery can take millennia. Moffitt stated “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 lifetimes.” She also added “It’s a gritty reality we need to face as scientists and people who care about the natural world and who make decisions about the natural world.”