The U.S. National Research Council has just released a synthesis of reports from thousands of scientists in 60 countries who took part in the International Polar Year (IPY) 2007-08, the first in over 50 years to offer a benchmark for environmental conditions and new discoveries in the polar regions.
Among the major findings is that global warming is changing the face of Antarctica and the Arctic faster than expected. For example, in 2007 scientists documented a 27 percent loss of sea ice in a single year, Brigham-Grette says. Also, ice sheets around the poles are now showing evidence of serious retreat, expected to continue and perhaps accelerate over coming centuries as warm ocean currents melt the ice front faster than anyone had grasped before. Sea level rise from melting polar ice sheets is today slowly affecting every shoreline on the planet.
“As a result of this work, we have a new benchmark. Seven of 12 Antarctic Peninsula ice shelves are either gone or now in severe decline,” she adds. “This type of information makes the report all the more important because the changes we expect to see in the next few decades are going to be incredible.”
As co-authors, she and Bindschadler testified last week before representatives of the National Science Foundation, its Office of Polar Programs, NASA, NOAA, the U.S. Geological Survey, Office of Naval Research, the State Department and the U.S. Arctic Research Commission. Additional briefings could be scheduled if there are questions or responses to the NRC from Congress, Brigham-Grette says.
Worldwide, scores of oceanographers, meteorologists, geologists, climate scientists, ecologists and other researchers contributed to the report. For example, biologists document diatoms, microscopic phytoplankton at the base of the food chain, in North Atlantic waters where they hadn’t been in 800,000 years, the last time the Arctic provided a cold barrier to migration, Brigham-Grette says. Fish specialists see commercial and other species migrating ever northward to suitable habitats. “The fishermen are following,” she says. “It’s a whole new ballgame for the U.S. Coast Guard and those trying to regulate harvests.”
The UMass Amherst geoscientist’s own research using ancient sediment cores from Northeast Russia’s Lake El’gygytgyn offers a new look at how Antarctic and Arctic warming over the last few million years occurred in sync when forced by the Earth system and feedbacks. “We’re beginning to see that when the west Antarctic ice sheet collapses, the Arctic warms up. This is a new benchmark linking warming events in these two places for the first time.”
In the Antarctic, new imaging techniques deployed during the recent IPY allowed scientists for the first time to visualize a new range, the Gamburtsev Mountains, with peaks as big as the Alps under the east Antarctic ice sheet. They may have been the ice sheet’s nucleus millions of years ago. Others found hundreds of freshwater lakes under Antarctic ice, with more being discovered every day.
Brigham-Grette says, “I think if you look at everything we’ve learned, we see the polar regions are much more vulnerable to global warming than we thought. Global biological and oceanographic systems are responding faster than we ever expected. Earth has gone through this before, and some past warm cycles have been extreme, but we as humans have never seen anything like it in our 10,000 years on the planet. It’s extraordinary.”
As they release the NRC report to policymakers this week, Brigham-Grette says the authors understand that leaders must try to balance the country’s energy needs at the same time they address global climate change by decreasing fossil fuel use.
Two social advances to emerge from the recent IPY are a remarkable increase in the number of women and minorities in leadership roles in science compared to 50 years ago along with the “massive” educational effort and increased interest in and public awareness of issues facing polar regions, she adds.
Among scientists, the IPY led to many new international and multi-disciplinary collaborations that promise to continue, says Brigham-Grette, plus a new international network of young polar scientists. “With the expense of travel and research today, no one country can do it alone, so there’s more sharing of resources and data. It’s a very much richer environment for study today.”