Cryospheric processes

Cryospheric processes are the processes involving ice sheets and glaciers.

Past events and their impact on cryospheric processes:

The last ice advance (60 000 – 20 000 BCE) led to an increase in glacial accumulation (snowfall and increased ice coverage providing extra snow to glaciers and ice sheets) so the global cryospheric store was considerably larger at this point.

Global sea level dropped at the same time; by about 120 m at the ice-maximum, although this was a relatively small proportion of total ocean storage.

Future events and their impact on cryospheric processes

The accumulation to glaciers and ice sheets (avalanches and snowfall) can vary depending upon global climate change. Recent warming of global climate has reduced accumulation and increased ablation (output) levels. Large volumes of summer meltwater and a reduction in winter accumulation has led to lower storage levels in global ice sheets and glaciers.

In some areas of the world, for example in northern Bangladesh, the potential long-term risk is that the glaciers in the Himalayas that feed many of the rivers in the country, will melt completely and then important water supplies will disappear with catastrophic effects for farmers in the country. The impact on drainage basins across the world is potentially very serious, with seasonal river levels dropping due to a lack of meltwater from individual mountain glaciers.

Hill slope changes will occur also as individual glaciers will melt completely, depositing their encased material as moraines.