Palm trees and crocodiles in the Arctic

Saturday, February 16th, 2008

No, this isn’t a dire climate prediction from one of Al Gore’s disciples. This description was of the Arctic’s distant past given by a paleo-oceanographer during the annual American Association for the Advancement of Science, being held this year in Boston (brrr, baby it’s cold outside). This particular scientist, Henk Brinkhuis from Utrecht University in The Netherlands, also said that 50 million years ago the Arctic was “stinky, swampy and freaking warm.”

exp302-8.jpgScientists know this because a few years ago an international consortium mounted the first ever deep ocean drilling expedition to the ice-covered Arctic Ocean. The ice-breaking drill ship pulled up sediment cores that represent climate history back to a time when Earth was a “greenhouse world” with no ice caps at the poles. Their 2004 expedition is written up in the Integrated Ocean Drilling Program (IODP) website. It was actually a feat to drill through thick sea ice to the ocean floor below and it took three ice breakers to do the job: a nuclear icebreaker from Russia to break up the floes, a Swedish ice breaker to grind them into slush, and a third ship to deploy the drill string.

Sediment cores are a time machine, scientists pore over the mud looking for fossil fragments, ancient microbes, pollen, and other pieces of evidence that give clues about the temperatures of the ocean and atmosphere. We know from the ANDRILL sediment coring project in Antarctica, covered in our Ice Stories website, diatoms and other plankton are good indicators of past climate because they are very particular about the environments they live in, including the temperature of the water.

Scientists at the session were quick to say that they don’t expect palm trees and crocodiles anytime soon in the Arctic. In fact, from these ocean cores it appears that ice started forming 40 million years ago, shortly after the maximum warm period, and as been an important climate driver in the Arctic Ocean since then. With recent thinning and changing sea ice cover around the North Pole, Kate Moran, a leader on the arctic drilling expedition, said “As scientists, it’s important to point out the issues that demontrate the vulnerability of our planet, that we could destroy this in 200 years.”

photo credit:
H Pälike © ECORD/IODP

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