Warm Water = World Wide Warning!!
The water cycle: Fresh water evaporates from the oceans, rains out over land, runs back into the seas, then repeats. Recently, a new study has found evidence that global warming has been speeding up this hydrological cycle.
Global annual precipitation is also dramatically increasing, but only half the increase is seen in river runoff, meaning that there is likely a large terrestrial storage of water−such as ground aquifers and glaciers− drying up. This would also be expected to eventually raise sea levels and generally dry temperate regions that depend on rivers to satisfy their thirsts.
Scientists have been predicting climate change would intensify the global water cycle. Computer models indicated that if this happened, there should also be “a redistribution of precipitation.” Driven by changes in atmospheric circulation patterns, rains and snowfall would increasingly ignore temperate regions in favor of zones nearer to the poles and tropics. Another feature of an intensifying water cycle: Storm intensity would increase. Along with the climate warming, long-frozen store of water (glaciers and permafrost) could be gushing into the seas from regions largely out of humanity’s view. One of the easiest ways to gauge ice and permafrost melting would be to tally stream flows around the world. Except that stream monitoring programs (never ubiquitous) have been diminishing in recent decades. Therefore a large share of the water flowing over land escapes any accounting.
Scientists have to “get creative” and figure out a new approach to figuring out stream flows across the world. To do this, they mined satellite data on sea level values (a gauge of the source of water) and data on sea-surface and cloud temperatures. These temperatures provided a gauge of ocean evaporation and eventual rainout. After their studies, the scientists found that the driver of this intensifying cycle, evaporation from the oceans, appears to be increasing by some 768 cubic kilometers per year.
With the water cycle accelerating, we could see much more violent storms, and many temperate areas (where most people now live) could become very dry. The scientists that conducted this experiment believe that it is global warming that caused this change in the water cycle, and if they are correct, then we, as the occupants of the world, need to do our best to fight global warming because that will eventually help slow down the water cycle to its natural speed.
However, we do have other options. If this increasingly faster water cycle will eventually “dry up the temperate areas of the world” then we, the informed civilians of the world who now know about this, can move to coastal areas where the land will still be fertile!
Erika F.
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