In a new study, researchers have collected evidence from Antarctic seashells that have revealed the earth was stressed and unstable even before the asteroid impact that led to wiping out of dinosaurs on the planet. The study, led by researchers at Northwestern University in the US, proceeded with the measurement of the calcium isotope composition of the fossilised snail and clamshells. The shells reportedly dated back to the Cretaceous-Paleogene mass extinction event, which wiped out dinosaurs from the face of Earth. The study will be published in the journal of 'Geology' later this month.
According to the findings of researchers, the chemistry of shells changed in response to the surge of carbon present in the oceans. Long-term eruptions from the Deccan Traps – a 200,000-square-mile volcanic province located in modern India – had led to the carbon influx. During the years leading up to the asteroid impact, the Deccan Traps spewed massive amounts of carbon dioxide (CO2) into the atmosphere. The concentration of CO2 acidified the oceans, directly affecting the organisms living there. This acidification is currently what's happening right now as mankind releases large quantities of the same gases in the atmosphere by burning fossil fuels.
"Our data suggest that the environment was changing before the asteroid impact. Those changes appear to correlate with the eruption of the Deccan Traps," said the author of the study Benjamin Linzmeier. "The Earth was clearly under stress before the major mass extinction event," said Andrew Jacobson, a senior author of the paper. "The asteroid impact coincides with pre-existing carbon cycle instability. But that doesn't mean we have answers to what actually caused the extinction."
The researchers said that understanding how the Earth responded to past extreme warming and CO2 input can help them prepare for how the planet will respond to current, human-caused climate change. Jacobson said that they think the ancient ocean acidification events are good analogues for what's happening now with anthropogenic CO2 emissions. "Perhaps we can use this work as a tool to better predict what might happen in the future. We can't ignore the rock record. The Earth system is sensitive to large and rapid additions of CO2. Current emissions will have environmental consequences."
(With agency inputs)