In a new article in the journal "Science," UC San Diego paleo-biologist Richard Norris and his colleagues report on findings that suggest our current ocean ecosystems may soon resemble the oceans of 50 million years ago. Norris, a researcher at UC San Diego’s Scripps Institution of Oceanography, studies fossils from deep sea sediment to help reconstruct a picture of an “ancient greenhouse world”. He says that world might be history’s closest analog to an environment that we should soon anticipate if humans continue to burn fossil fuels at their current pace.
In that ancient world, CO2 concentrations reached 800 to 1000 parts per million, and polar oceans reached 2°C (53°F) -- similar to current ocean temperatures offshore San Francisco. Subsequently, those ancient oceans contained very few coral reefs, the tropical surface waters were like a hot tub, and food webs could not sustain nearly as many large sea animals as we have now.
For the past million years the earth hadn’t seen CO2 levels in the atmosphere anything like those of 50 million years ago, but the report says that human activities have pushed CO2 levels back to alarming measures, higher than ever in human history. According to the research, at its current pace Earth could recreate the CO2 content of the ancient world in just the next 80 years. But Norris also says that if humans curb their fossil fuel activities now, it could significantly curb the amount of environmental instability expected in the coming years.
What’s new in this research that focuses on the state of oceans? What kinds of things does the world stand to lose if coral reefs and large marine animals drop out of the oceans? How does this intense climate warming compare to other climate changes in the planet’s history?
Dr. Richard Norris, Paleo-biologist at Scripps Institution of Oceanography at UC San Diego