URI_Research_Magazine_Momentum_Spring_2015_Melissa-McCarthy

Plio-Pleistocene sediment cores from the eastern tropical Pacific Ocean, North Pacific Ocean, and the Arabian Sea.

Rebecca Robinson Associate Professor Oceanography

timescale is that the Pliocene was a relatively warm climate,” Robinson says. “The continents were all in the same place and the ocean circulation was, to some degree, similar to today. It’s an interesting place to ask, what was the chemistry of the ocean like in a warm climate?” Some scientific literature has voiced concerns that the ocean will lose oxygen as the Earth warms. Just like a bottle of soda staying carbonated for longer in a fridge than at room temperature, the ocean holds more gas when it is colder. If global temperatures increase, some scientists worry, than the ocean will hold less oxygen. But in her examination of Plio- Pleistocene sediment cores from the

Robinson mainly studies the Pliocene and Pleistocene (Plio-Pleistocene), two geological eras encompassing a period in the Earth’s history about 5 million to 12,000 years ago. During the Pliocene, the Earth was two to three degrees warmer, and the global concentration of carbon dioxide in the atmosphere was 400 parts per million (ppm). “The Pliocene is considered a good analogue for where the planet is headed today,” she says. In 2012, the Mauna Loa Observatory in Hawaii recorded atmospheric carbon dioxide levels of 400 ppm. The Pleistocene was, alternatively, a period of cooling and ice ages.

During the last 50 years, there have been significant changes to diatom communities in Narragansett Bay.

“My motivation for working on this

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