And as the interest you pay on the loan is very likely lower than your required rate of return on your own capital, you will make more money the more money you loan.

That is, if the business works out. If it doesn't you're in deep shit. Which is kinda what risk means.

Let me give you an example. You buy shares for one million euros. The share price goes up by 10 %. You make 100,000 euros. If the shares fall by 10 % you lose 100,000 and still have 900,000 left.

Let's say you instead invest your own million and loan nine more millions and buy shares for all of it. If the share price goes up by 10 % you have made a million, you've doubled you investment! But if the share is down by 10 % you lose one million and have no money left. If the share is down 20 % you not only lose all your money but you are one million euros in debt.

Leverage is dangerous. Of course, this is why the limited liability corporation is so important. Even if the business goes to Hell, you can't lose more money than you've invested, there's no going into debt.

Though in the real world, if you're an entrepeneur, the banks will only lend money to your project if you've invested a lot of your own money into the project, and you've often gotten this money from stuff like mortaging your house.

Peak oil is not an energy crisis. It is a liquid fuel crisis.