Scientists predict that within twenty years, the remaining glaciers at Glacier National Park will melt away.

Whether it's because of human industry or natural cycles, temperatures are rising. And when temperatures rise, glaciers melt. Glaciers are more than just pretty pictures. They're the main sources for many rivers that people depend on for drinking water, irrigation, and hydroelectric power.

Thankfully, the rivers aren't drying up. But the amount of glacier water affects a river's flow volume. The lower the flow volume the less water there is for drinking, power, and everything else people depend on rivers for.

Also, greater water volume helps dilute a river's chemical content. The less water a river has, the higher the chemical concentration, which can pollute a lake fed by the river.

Some scientists make this argument: higher temperatures mean that more water will evaporate from the oceans, which means more precipitation, including snow... so maybe some glaciers will actually grow even though it's getting warmer.

Sure, some glaciers are growing temporarily thanks to unusual amounts of snow, but they're the exception to the rule. Generally, glaciers grow when the amount of snow that melts in the summer is less than the amount that falls in the winter. Right now, more snow is melting than falling.