Could Icebergs Be Used as A Source for Drinking Water-

　　Could tapping into icebergs as a freshwater source be practical? The concept of exploiting icebergs for water has been debated for years, often considered a幻想 scientific notion yet not entirely beyond the realm of possibility. It has appeared as a futuristic concept, perhaps closer to becoming reality. Despite floating in saltwater, the ice within icebergs is free of salt, essentially being compressed snow. Melting iceberg ice would produce drinkable water after neutralizing any bacteria. The main obstacles to using icebergs as a primary drinking water source have been the costs and risks associated with their transportation. This topic has been widely discussed in the media and has even led to some humorous hoaxes. Though the idea is traditional and enduring, it seems to have avoided recent critical examination. Usually linked with the Southern Hemisphere, particularly Antarctic ice, there are Northern Hemisphere entities seriously investigating this possibility. The question persists: can we realistically envision a future where Antarctic ice becomes a harvested resource?

　　Iceberg water is already being used on a small scale in the Northern Hemisphere for certain drinks, both alcoholic and non-alcoholic. The use of icebergs has begun. The inaugural international conference on this topic was held in 1977 (Balaban 1979: Husseiny 1978). Schwerdtfeger (1981) provided a valuable summary of the concept’s status and progress in related sciences up to that time, with Schwerdtfeger (1982) offering additional perspectives. His research was based on the premise of towing icebergs, concluding it was unlikely to be feasible due to high fuel costs. Nevertheless, with new possibilities arising and a decrease in fuel costs, this paper seeks to explore the concept further.

　　The global human population, totaling six billion, consumes about 3,240 km3 of water annually from a renewable resource of around 41,000 km3. Antarctica possesses approximately 30 million km3, accounting for 90% of the world’s ice and 70% of its freshwater, producing roughly 1,250 km3 of icebergs each year (about three to four times Australia’s annual renewable water supply). With projections that the world population could double to 10-12 billion in the next 50 years, combined with uncertainty about global change, the pressure on the global water supply is anticipated to increase dramatically (Australian water usage has risen by 65% since the early 1980s). Icebergs will undoubtedly become part of this increasingly strained resource pool. The idea that the next conflict will be fought over water access is often mentioned.

　　Small-scale experiments using the German Antarctic research vessel RV Polarstern have involved letting iceberg water reside in plastic for several months at sea (in the cold Antarctic waters) to assess water quality retention. The outcomes seemed to suggest no degradation. The report proposed an acceptable seawater inflow of up to 2.5% while still producing usable water, although I would contend that 2.5% is too high, preferring a figure closer to 1% or lower. This simple concept has been applied to encasing ice floes weighing 3,000 tonnes and theoretically to icebergs of about one million tonnes. The plastic comes in rolls 2 meters wide, with adjacent rolls unrolled and welded concurrently. As the sheet is welded, it is folded into an accordion pattern on a floating platform or barge situated at the iceberg’s upstream side.

　　The plastic is then allowed to sink and, if the currents are strong enough, carried underneath the iceberg, or else pulled by cables if the current is too weak. Once the iceberg’s underside is covered, air sacs or tubes within the plastic are inflated, causing the plastic to rise and keeping most seawater out. Encasing the ice mass’s top is more challenging but achievable. The process of dragging the plastic over the iceberg’s summit is hindered by friction, overcome by pulling cables from the platform to a tug across the iceberg’s top, using air-filled rollers to reduce friction. With the iceberg enveloped, the plastic is sealed to encase the entire mass, which can then be towed or moved by surface currents.

　　It is clear that the economics of wrapping a single iceberg are not viable, only suitable for experimental and developmental purposes. If the concept ever becomes economically feasible, it would likely require wrapping multiple icebergs, providing the opportunity to supply water to various locations. Any proposal to exploit Antarctic resources must be evaluated under the Protocol on Environmental Protection to the Antarctic Treaty, particularly south of 60°S latitude, and would come under national jurisdiction within territorial waters. During negotiations for the unratified Convention on the Regulation of Antarctic Mineral Resource Activities (CRAMRA), ice was excluded from consideration as it was regarded a renewable resource. The吸引力 of using icebergs as a water source lies in the minimal environmental impact in the Antarctic and the potential to alleviate environmental issues at or near the destination.