00:00Glaciers are masses of ice that form at high elevation due to snowfall staying over the
00:16entire summer and then transforming into fern and ice and flowing downhill.
00:23So glaciers are streams of frozen water that can exist and persist at very high elevation
00:31in the mountains around the world.
00:33Glaciers take up water in cold and wet periods and they provide water in hot and dry periods.
00:43And with this role, they have the possibility to fill in lags in the water availability.
00:51This makes them very important, especially in dry regions where water is intensely used
00:57for agriculture or drinking water.
01:09Glaciers are found in all major mountain ranges around the globe.
01:14The biggest glaciers are found in Alaska and Patagonia, but also around the big ice sheets
01:21of Greenland and Antarctica.
01:22We don't count these huge ice sheets, Greenland and Antarctica, as glaciers.
01:28However, the ice caps that are around these ice sheets, they are termed glaciers.
01:34The implications of this are multifaceted, which includes the threatening of the long-term
01:39water resources.
01:40So long-term water security is really at stake here.
01:44For not just a few millions, it's literally hundreds of millions directly in the Hindu
01:48Kush Himalaya region, it was estimated it could be up to almost two billion.
01:53And globally in the interconnected economy, it's everyone around the world who's indirectly
01:58impacted from these dramatic changes.
02:00If we look at the observed changes in the last decades, in the last century, we see
02:06that air temperature everywhere around the earth has strongly increased, while snow precipitation
02:14is more or less stable, or even on a decline.
02:18And these two factors combined, they result in increased melting of the ice and therefore
02:25a retreat of the glacier tongues into higher elevation.
02:30The biggest impact of glacier melt is the rise in global sea levels.
02:36So all the water that has been stored in the glaciers around the globe is released and
02:43is ending up in the oceans.
02:46This increase in global sea level by glacier melting isn't huge, it's a few millimeters
02:53per year, but still, when combined with tides and with flooding, this can be very important
03:04to many people around the earth living in the coastal regions.
03:11So this is a major impact that will increase in importance in the future and will also
03:17be very long lasting.
03:19It's not something that we'll be able to stop within the next decades.
03:24So we have to be concerned about very long time periods.
03:28As glaciers retreat, we are also seeing lots of new hazards in high mountain regions.
03:35For example, outburst floods from glacial lakes, instabilities causing ice or rock avalanches.
03:46And this can be a hazard for people going to the mountains, mountaineers or hikers,
03:53but even more so for valley communities that are living at the foot of the mountains.
03:59We can mitigate the melting of glaciers by curbing CO2 emissions.
04:06This is very clear.
04:08Glaciers are responding to rising air temperatures and we can stabilize air temperatures globally
04:15with bringing CO2 emissions to zero.
04:18So many nations around the globe are attempting this, are setting goals to reduce the CO2
04:26emissions.
04:27However, it's not fast enough at the moment.
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