Marine biologists are searching for evidence of what our oceans will look like if carbon dioxide levels continue to increase. Thirty percent of the carbon dioxide, or CO2, released into the atmosphere is absorbed by the ocean, leading to a process called acidification. Shellfish and coral reefs are particularly impacted, according to Jason Hall-Spencer of Plymouth University. “We’ve never put this much carbon dioxide into the ocean before,” he said. “It’s never happened before in Earth’s history. Not this quickly.” NBC’s Ann Curry reports.