It’s this time of year again – the European Geosciences Union’s (EGU) General Assembly is on.
Some 8,000 earth scientists have made it this year to the charming Austrian capital of Vienna. All sessions I went to today were well-attended. The discussions, in the lecture rooms and on the floors, were lively as ever.
The sessions this morning about mountain hydology, glaciology and the cryosphere – ice and snow, that is – were quite a treat. I listened to a pretty provocative exchange of views on arctic sea ice retreat. Are estimations about the rate of the retreat still to conservative, or is the demise of ice exagerrated? Some scientists believe that arctic ice is merely in a high flow state, and that the massive export through narrow passages of arctic ice into warmer waters will be more or less back to normal at some point. Optimistic!
The retreat of mountain glaciers, which provide a reliable water resource for many lowland regions, is one of the most striking signs of global warming. But glaciologist warned today that the behaviour of many large glaciers is worryingly understudied. Well, not in the European Alps or the Rocky Mountains. But Indian or Chinese earth scientists are often not the outdoor fanatics which most of their European or North American colleagues doubtlessly are (the uninformed passer-by could easily mistake the EGU for an assembly of mountaineers
Georg Kaser, an Innsbruck-based glaciologist, told me that fieled measurements in the Himalayas, for example, are nororiously scarce. Only for a few smaller glaciers in the region there exist reliable mass balance data. Simply extrapolating the few existing measurements is highly problematic, as larger glaciers may behave quite differently. The assumption that the exceptionally large shrink rate observed in few small glaciers is typical for the whole Himalayas is premature, he says.
Lack of field measurements is an even bigger constraint in the Hindu Kush mountains in Afgahnistan. Glaciological studies in this Taliban-controlled region can only be done by remote sensing. No western funding agency would currently support any field research there.
Meltwater from the the Hindu Kush’s 3,500 or so glaciers is crucial for recharging lowland aquifers, and until 30 years ago supplied Kabul and other large cities with sufficient water. But as the glaciers are getting smaller and smaller, and because snow comes later in the years and starts to melt earlier, people are now forced to take water from often polluted wells and reservoirs.
Bruce Molnia of the US Geological Survey (USGS) in Virginia showed some impressive satllite images of glacier retreat in the Hindukush. The USGS has also begun training Afghanistan geologists with a view of them taking up field research in the Hindukush as soon as the security situation allows, he says.
Not everything worked today, though. The ‘Great Debate’ on ‘Mining versus Nature’ proved to be a rather weary and uninspired exchange of remarkably unsurprising standpoints. I do hope that tomorrow’ debates on energy options and geo-engineering will be more enlightening.