Sept 13 (Reuters) - Scientists are racing to collect ice cores – along with long-frozen records they hold of climate cycles – as global warming melts glaciers and ice sheets.

Late last year, German-born chemist Margit Schwikowski and a team of international scientists attempted to gather ice cores from the Grand Combin glacier, high on the Swiss-Italian border, for a United Nations-backed climate monitoring effort.

The mission on Grand Combin underscores the major challenge scientists face today in collecting ice cores: Some glaciers are disappearing faster than expected.

In its most comprehensive climate report to date, published in August, the UN concluded that “human influence is very likely the main driver of the near-universal retreat of glaciers globally since the 1990s.” The report also said that without immediate, large-scale action, the average global temperature will reach or exceed 1.5 degrees Celsius above the preindustrial temperature average within 20 years.

Emilie Beaudon, Postdoctoral Scholar, cuts an ice core into samples to be tested at the Byrd Polar and Climate Research Center in Columbus, Ohio, U.S., January 15, 2021.

The Byrd Polar and Climate Research Center gathers and studies the history of the Earth's climate as it's recorded in ice cores from glaciers around the world.

Ice cores like those from Grand Combin have helped scientists illustrate humanity’s impact on earth's climate by providing a record of greenhouse gases dating back well before industrialization.

Another member of the Grand Combin expedition, Italian climate scientist Carlo Barbante, said the speed at which the ice on the Alpine massif had melted in the last few years was “much higher than it was before.” Finding the wet cores was a "complete shock," he said.

As a result, Barbante and other scientists - including Schwikowski - sped up plans to extract a core from the Colle Gnifetti glacier on the summit of the Alps’ Monte Rosa, a few hundred meters higher than Grand Combin.

A 2009 discovery by American scientist Douglas Hardy of the mummified remains of a 19th century pig on one of the highest points of the mountain’s glaciers suggests some of the climate history the scientists are hoping to retrieve is already gone.

"A hundred years from now, when the Alpine glaciers will be completely disappeared, we will have the samples" for future generations of scientists, said Barbante.

That team of scientists included U.S.-based ice core paleoclimatologists Lonnie Thompson and Ellen Mosley-Thompson, who are husband and wife.

Some of the cores Thompson and his team have collected are the only remaining ice from some glaciers.

“Ice has a wonderful archive of not only the climate, but also the forcings of climate," the major causes of climate change, Thompson said