Scientists believe the global sea level will rise one meter this century because of warmer temperatures that are melting the ice shelves at both poles, potentially flooding coastlines and dramatically affecting the lives of millions around the world. Two scientists participating in a live International Polar Day event March 12 provided their insights into what the future may hold and what decision-makers should do to address the issue.

Icebergs float off Antartica’s coastline in the Great Southern Ocean.

Dr. Robert Bindschadler, a NASA scientist who has led 15 field expeditions to Antarctica during his career, believes that despite the radical changes now occurring, no one really understands the dynamics to predict precisely how much or how fast the ice sheets will change. The computer models do not simulate the conditions that scientists are now observing, he said.

Dr. Graeme Pearman, the former Chief of Atmospheric Research for the Australian Commonwealth Scientific and Research Organization (CSIRO) and the author of 150 scientific papers dealing primarily with the global carbon budget, contended, meanwhile, that scientists and others have perhaps underestimated the rate of change. While scientists gather more data, he believes nations worldwide need to reduce the level of greenhouse gases - primarily carbon dioxide - that they release into the atmosphere.

Talks Presented Live Via Web Videoconference

Both presented talks at a live International Polar Year Web-video conference organized by International Action on Global Warming (IGLO), an activity of the Association of Science-Technology Centers. International Polar Year (IPY) is a large international and interdisciplinary research effort focused on the Earth‚s polar regions, connections between the polar regions and lower latitudes, and educational outreach. Polar regions are now serving as sensitive barometers of environmental change.

Launched last March, this fourth IPY will continue through March 2009, featuring quarterly International Polar Days to raise awareness of the polar regions and the scientific research taking place at both.

Events during the March 12-13 Polar Day observance addressed the topic of “Changing Earth, Past and Present”. It focused on change over glacial and interglacial periods that have occurred during the past million years. As part of this celebration, Bindschadler participated in a second event the following day. He was joined by Northern Illinois University scientist Dr. Ross Powell who discussed the ANDRILL project, which is characterizing the variable Antarctic environment over the past few million years as recorded in sea-floor sediments near McMurdo Station. In all events, students worldwide participated by Internet connection.

Satellite Imagery Now Capturing Change in Real-Time

Indeed, the Earth has experienced many ice ages, interspersed with periods of warming, Bindschadler said. What is different in recent years, however, is the advent of satellite technology that is capturing in real-time the very rapid changes now occurring, he said. In 2002, the 200-meter thick Larsen B Ice Shelf on the eastern side of the Antarctic Peninsula disintegrated in just six weeks - an event captured by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument flying on the Terra spacecraft. “It was like snapping your fingers and it was gone,” he said.

Satellite imagery also is telling scientists where other extreme changes are occurring. One such place is the Pine Island Glacier, which drains into the Amundsen Sea. The ice stream is moving one foot every hour, traveling much faster than just a few years ago - a change faster than scientists originally thought possible. Scientists speculate that warm ocean waters are moving beneath the floating extension of the glacier, causing it to melt faster and reducing the pressure holding back the land-based glacier. However, they do not know for certain because the ice overlays the water, making it difficult to obtain temperature measurements.

Under an IPY-sponsored research effort, he and his colleagues plan to drill holes into the ice sheet so that they can deploy instruments to measure ocean temperatures. The automated weather station they set up recently is now sending data to them hourly. “The answers to improving our models lie right there,” Bindschadler said. “We need the numbers.” With them, the world’s scientists will be able to greatly improve their ice-sheet models and give decision-makers more precise information on how much and how fast the ice sheets are changing and what that means for future sea level.

More Urgent Action Needed

While scientists gather this all-important data, Pearman believes the climate changes as observed at both poles warrant a more urgent reduction in the release of greenhouse gases. “We know the climate is changing,” he said. “We’ve known it for almost 100 years. We also know there is a connection between the amount of carbon dioxide in the atmosphere and the climate.”

“There is a degree of urgency around this issue,” he said. “In the last few years, we’ve suddenly realized we’ve underestimated the rate of change,” referring to the 20-percent reduction in the extent of Arctic sea ice in September 2007. “We don’t know how the ice sheets work. They will be affected by how much heating goes on. We don’t want them to melt too quickly,” he added.

Compounding the problem is the fact that some nations emit more pollutants than others, even though the problem affects everyone. Undoubtedly, energy use and consumption will change over the next 10 to 20 years as more nations reduce their dependence on fossil fuels and switch to wind, solar, or even advanced nuclear energy. Wealthier nations will be able to handle the changes more easily; other less wealthy nations will not. “A real challenge is how we’re going to share these inequities.”

To see this International Polar Day event and others, go to www.astc.org/iglo.

For more information about IPY, go to www.ipy.org.