It is very possible that sometime in the not-so-incredibly far future, we will run out of helium — the very thing you can currently get from any dollar store. This means that in an estimated 200-300 years, people won't be able to experience what it's like to inhale helium to get that funny high pitched voice. Balloons will have to be filled with a new gas for them to continue existing, preferably one that isn't highly explosive like hydrogen.
Although it's the second most abundant element in the universe, it's a real concern that what we have on Earth may be entirely depleted. This is hard to stop from happening simply because helium floats! When one of your helium filled party balloons pops, that helium is forever lost. Since it's lighter than nearly all other gases, it floats all the way up to the outer layers of the atmosphere where it becomes extremely diluted and unrecoverable. It can even be swept away into space by solar winds and forever lost.
Running out of helium may not seem like a big deal. After all, I'm sure we could all survive without balloons at birthday parties. But helium is used in more applications than most people probably realize. For example, it's used in treating breathing conditions like asthma and emphysema. MRI scans rely on helium in a liquid state. It's also used to provide safe cooling in many ways, like keeping a nuclear reactor cool. Losing this resource completely will �call for changes and adjustments to many things people don't even think about.
Helium is not a renewable resource. Once all of the gas trapped within the earth has been released, the only helium remaining will be from whatever we currently have stowed away. Luckily, scientists have been preparing for this for sometime now. Because of the concern of running out, the United States had actually been collecting and storing helium starting all the way back to the 1960s. It is being held in a reserve called the Bush Dome, in which it currently holds about 600 million cubic meters of helium. Hopefully this will be enough to allow for scientific and medical uses to continue while research begins for a suitable alternative. �