Effects of Climate Change on Glaciers and Sea-Ice

One noticeable effect of increases in temperature is decreases in the ice content of glaciers and sea-ice. Increases in temperature might be due to climate change triggered by human intervention or triggered by natural events. This page gives links to scientific articles that discusses decreases in ice level.

Researchers taking a new look at the snow and ice covering Mount Everest and the national park that surrounds it are finding abundant evidence that the world's tallest peak is shedding its frozen cloak. The scientists have also been studying temperature and precipitation trends in the area and found that the Everest region has been warming while snowfall has been declining since the early 1990s.

Since their maximum extension, reached between 1650 and 1750, during the Little Ice Age*, the tropical Andean glaciers have gradually retreated. Over the last 30 years, however, their decline has taken dramatic proportions. This summary clearly shows the peculiarity of these last decades, with melting speeds that had never been reached before in 300 years: the surface areas of glaciers in Colombia, Ecuador, Peru and Bolivia were reduced from 30-50% since the end of the 1970s and up to 80-100% in extreme cases. This new study confirms the acceleration of climate change in this part of the world at the end of the 20th century.

The planet's two largest ice sheets have been losing ice faster during the past decade, causing widespread confusion and concern. A new international study provides a firmer read on the state of continental ice sheets and how much they are contributing to sea-level rise.

The forecast by Brigham Young University geology professor Summer Rupper comes after her research on Bhutan, a region in the bull's-eye of the monsoonal Himalayas. Published in Geophysical Research Letters, Rupper's most conservative findings indicate that even if climate remained steady, almost 10 percent of Bhutan's glaciers would vanish within the next few decades. What's more, the amount of melt water coming off these glaciers could drop by 30 percent.

Sea levels are rising faster than expected from global warming, and University of Colorado geologist Bill Hay has a good idea why. The last official IPCC report in 2007 projected a global sea level rise between 0.2 and 0.5 meters by the year 2100. But current sea-level rise measurements meet or exceed the high end of that range and suggest a rise of one meter or more by the end of the century.

Glaciers in the eastern and central regions of the Himalayas appear to be retreating at accelerating rates, similar to those in other areas of the world, while glaciers in the western Himalayas are more stable and could be growing, says a new report from the National Research Council.

"This continues the trend in accelerated ice loss during the past two and a half decades and brings the total loss since 1980 to more than 10.5 metres of water equivalent," said Professor Haberli. During 1980-1999, average loss rates had been 0.3 metres per year. Since the turn of the millennium, this rate had increased to about half a metre per year.

The Montana park has 26 named glaciers today, down from 150 in 1850. Those that remain are typically mere remnants of their former frozen selves, a new gallery of before and after images reveals.

Photographs taken by members of a WWF expedition to the Ruwenzoris last month show a massive reduction in glacier size when compared with similar images from the 1950s, probably from increased temperatures or humidity.

A revised outlook for the Arctic 2008 summer sea ice minimum shows ice extent will be below the 2005 level but not likely to beat the 2007 record. DAMOCLES will dispatch eleven research missions into the Arctic this autumn to better understand the future of the sea ice.

Project MARGO offers more exhaustive data than that available at present and will serve to represent more exact models of the past and predict the climate's evolution in the future. In addition, MARGO has enabled researchers to discover new aspects of the Last Glacial Maximum, such as the fact that the ice covering the Northern Atlantic Ocean and extending down to the British Isles was not permanent but actually melted in the warmer months to a much larger extent than it does now.

The new still tentative data of more than 80 glaciers confirm the global trend of fast ice loss since 1980. Glaciers with long-term observation series (30 glaciers in 9 mountain ranges) have experienced a reduction in total thickness of more than 11 m w.e. until 2007. The average annual ice loss during 1980-1999 was roughly 0.3 m w.e. per year. Since 2000, this rate has increased to about 0.7 m w.e. per year.

A three-year study, to be used by the China Geological Survey Institute, shows that glaciers in the Yangtze source area, central to the Qinghai-Tibet plateau in south-western China, have receded 196 square kilometres over the past 40 years.
Glaciers at the headwaters of the Yangtze, China’s longest river, now cover 1,051 square kilometres compared to 1,247 square kilometres in 1971, a loss of nearly a billion cubic metres of water, while the tongue of the Yuzhu glacier, the highest in the Kunlun Mountains fell by 1,500 metres over the same period.

Look at Washington State. The Nisqually Glacier on Mt. Rainier is growing. The Emmons Glacier on Mt. Rainier is growing. Glaciers on Glacier Peak in northern Washington are growing. And Crater Glacier on Mt. Saint Helens is now larger than it was before the 1980 eruption. (I don't think all of the glaciers in Washington or Alaska are being monitored either.)

Glaciation of Earth also occurs every 100,000 years. Lisiecki found that the timing of changes in climate and eccentricity coincided. "The clear correlation between the timing of the change in orbit and the change in the Earth's climate is strong evidence of a link between the two," said Lisiecki. "It is unlikely that these events would not be related to one another."

The Tibetan Plateau is the largest and highest mountain region on Earth with glaciers whose meltwater provides the water supply for more than 1.3 billion people through several of the largest rivers in Asia. In a thesis in Physical Geography from Stockholm University, Jakob Heyman shows that the glaciers in Tibet have remained relatively small and have not been much larger than today for tens of thousands to hundreds of thousands of years back in time.

The researchers proceeded to analyze a series of measurements based on many parameters related to climate, glaciers, and streamflow in order to compare this data with existing information. Although these studies have revealed a clear tendency toward a reduction in streamflow during the summer, the impact of melting glaciers on the annual flow remains unclear. "Many factors can have an influence on water quantity," explains Annina Sorg. "Precipitation level, evaporation, and even human interference on the hydrological cycle are all factors to consider."