Thousands of scientists from more than 60 countries will head to the Arctic and Antarctic regions in an ambitious two-year project beginning Thursday to study the effects of global warming.

The International Polar Year (IPY) program will be the fourth comprehensive study of the two regions and the first in 50 years.

Scientists will pursue physical, biological and social research of the Arctic and Antarctic from March 2007 to March 2009 in an attempt to gauge the impact of climate change on regions expected to be particularly vulnerable to rising temperatures.

More than 50,000 scientists will work on 228 projects, chronicling changes in snow and ice patterns and the impact of these changes on other regions around the globe. In addition to climate change, the research will look at the unique biodiversity and physical geography of the regions and the culture of northern peoples.

It's the first polar study since a 1957 to 1958 study that featured the first overland crossing of Antarctica. Two other studies were conductedfrom 1882 to 1883 and from 1932 to 1933.

The latest polar research program will take place against a backdrop of rising concern about the future of the glaciers in the two polar regions.

The February report from the United Nations Intergovernmental Panel on Climate Change called global warming "unequivocal" and predicted average worldwide annual temperatures would increase between 1.8 and four degrees C over the next century and a rise in sea levels ofbetween 18 and 59 cm over the same time period.

It also said the increase in temperatures would be greater in the two polar regions.

But scientists are still relying on sparse information from a few on-site observation facilities in the Arctic and Antarctic, said Michel Jarraud, the Secretary-General of the World Meteorological Organization, the organization leading the research along with the International Council for Science.

"It is essential to install more and increase satellite coverage to gain a better overall picture of how rapidly these areas are changing, and of the global impact of these changes," he said.

The IPY program will formally begin in Paris on Thursday, March 1, but opening ceremonies were scheduled on Monday, February 25 in London, Washington and Strasbourg, Germany.