Keep in mind that the derivatives often trade with 40x leverage. So, the 600Trillion listed is really only held with perhaps 15T dollars. For example, if you buy $100K derivs with a $2500 account, once your account goes to $0, or whatever the margin value is, the broker liquidates. So, you wont lose 100K, you might lose around $3K.
There was also a post about the world GDP being ~60T while some form of debt was also ~60T. I disagree that it would only take one year to pay back the debt. Any debt payback would have to cone from savings. So, assuming a rather high savings rate of ~7%, it would take ~14 years to pay back this debt, assuming all savings goes to debt payment.