The United States alone consumes 18.9 million barrels of oil every day, rain or shine. And China’s appetite grows more ravenous by the minute, with daily consumption doubling from 5.5 million barrels in 2003 to nearly 9.8 million in 2011.

Aside from a brief downturn during the recession, global oil consumption has been moving inexorably higher.

Worldwide oil consumption passed its pre-recession 2007 peak in 2010 and continues to rise. It is projected to reach 90.2 million barrels per day this year. Meanwhile, the world’s oil companies will only produce 90 million barrels per day. 

In other words, demand will outstrip supply by 200,000 barrels per day, or by about 73 million barrels this year.

We can barely feed our energy appetite today. And we’re getting hungrier. Per-capita consumption in China and India is still less than one-tenth that of the United States, but these growing middle classes are catching up fast. In fact, 18 million new cars hit the road in China last year — compared with 14.5 million in the United States — stretching oil supplies even thinner.

Meanwhile, most production grounds have been in a steady decline for decades. Future oil exploration activity will be focused in deep offshore basins, which are expensive to tap.

That’s why I’m advising readers to invest in the “Oil of the 21st Century.”

#-ad_banner-#I call it this because no other precious resource in the world can do what it does. Businesses are willing to pay hundreds of millions a year for its unique qualities — it is a key ingredient in a wide range of products, from pharmaceuticals to rocket fuel. But its real magic is that, pound for pound, this featherweight metal can store more electric energy than just about any other material. 

I’m talking about lithium.

You see, lithium is the battery maker’s best friend. Rechargeable lithium-ion batteries have twice the energy density of yesterday’s outdated nickel-cadmium technology, making them indispensible in everyday products from digital cameras to portable video game consoles. 

You’ve probably got some lithium within reach right now. If you own an iPad, iPod or iPhone, you definitely do. 

But electronic gadgets aren’t why I’m so excited by lithium. 

The real action is in cars — electric cars, to be specific.

President Barack Obama wants to put 1 million electric cars on the road by 2015, and 10 times that amount by 2018. The government is bankrolling the transition with some heavy incentive dollars. 

GM is going electric with the Volt. Ford is planning a battery-powered car based on the Focus. And, of course, Toyota has the Prius… Honda the Insight… and Nissan the Leaf. 

But car makers won’t be the biggest winners from the craze for electric vehicles. Instead, I think there’s another way to make even more money from the transition to battery power.

Unlike gold, silver and other metals, it is virtually impossible to invest directly in lithium. The Global X Lithium Exchange Traded Fund (NYSE: LIT), however, is the next best thing. 

The fund’s three largest positions, or roughly half its portfolio, is invested in companies engaged in lithium mining and refining. These companies have diverse business lines, so these aren’t pure plays. But collectively, this trio accounts for the majority of the world’s lithium production. The rest of the fund’s assets are invested in a well-rounded mix of battery-makers.

Risks to Consider: In many respects, this industry is still in its infancy. So it’s difficult to say which technologies will emerge victorious and which will become historical footnotes. That means there will be some spectacular winners in this field, but also some big losers.

Action to Take –> That uncertainty makes Global X Lithium the perfect investment for this space — rather than place all your bets on one horse, you can spread it among 20 of the strongest contenders. My money says that several of these will go on to be multi-baggers within the next couple years.

P.S.  The “Oil of the 21st Century” is just one of the scarcity plays I’ve got my eye on. Another one that could potentially be even more profitable could mark the end of OPEC as we know it, while easily turning a $5,000 investment into $50,000 or more in the next five years. Go here to learn more.