"The helium we have on Earth has been built up over billions of years from the decay of natural uranium and thorium. The decay of these elements proceeds at a super-snail's pace." Have you heard of radioactive elements? These are elements like the type used in nuclear power plants that decay through time producing energy and smaller particles like helium.

So yes, we are on our way to running out of helium. Helium is lighter than air, as you know from balloons, so some helium is lost naturally as it floats up to the top of the Earth's atmosphere and eventually is lost to outer space.

Sources of helium: "Some natural gas deposits have as much as 7% helium. Such deposits have been found in Texas, Russia, Poland, Algeria, China and Canada. Helium extracted from these natural gas reserves is the single source of helium."

Helium is actually being depleted very rapidly, a recent report said that one of the world's biggest supplies of Helium in Amarillo, Texas, is expected to run out in the next eight years!!

"Helium is non-renewable and irreplaceable. Its properties are unique and unlike hydrocarbon fuels (natural gas or oil), there are no biosynthetic ways to make an alternative to helium. All should make better efforts to recycle it."

So does this mean no more balloons!? Possibly.

Helium is important for many manufacturing processes, welding, deep sea diving etc.

There are some gases like hydrogen and argon that can be used in its place in some situations. But argon will not make balloons float and itself is rather rare. Also Hydrogen is very flammable so will not replace most applications of helium. Many manufacturers have instilled processes to recycle helium by not letting it escape to the atmosphere. Recycling will be important to preserving our helium supplies, until the day when are civilization is adavanced enough to produce nuclear fusion reactors (like the reactions that take place on the Sun) to produce helium. Although scientists are actively working on this, it is a long way off now. As a note some helium is produced indirectly in nuclear fission reactors (like nuclear power plants) but the quantities are far smaller than our need.

These are the sources I used:
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