Frank Knight distinguished between 'risk' and 'uncertainty' which he defined uncertainty as an option for which only the array of possible outcomes, but not their probabilities is known. See his Risk, Uncertainty, and Profit, Boston and New York: Houghton Mifflin Company, 1921, Chapter 6.

According to the standard ISO 31000:2009, risk is defined as “effect of uncertainty on objectives”. Uncertainty may be a result of the inadequacy of the available information or limited knowledge (Helbing, 2013).

“Uncertainty must be taken in a sense radically distinct from the familiar notion of risk, from which it has never been properly separated.... The essential fact is that 'risk' means in some cases a quantity susceptible of measurement, while at other times it is something distinctly not of this character; and there are far-reaching and crucial differences in the bearings of the phenomena depending on which of the two is really present and operating.... It will appear that a measurable uncertainty, or 'risk' proper, as we shall use the term, is so far different from an unmeasurable one that it is not in effect an uncertainty at all” (Wikipedia).

For example, if it is unknown whether or not it will rain tomorrow, then there is a state of uncertainty. If probabilities are applied to the possible outcomes using weather forecasts or even just a calibrated probability assessment, the uncertainty has been quantified. Suppose it is quantified as a 90% chance of sunshine. If there is a major, costly, outdoor event planned for tomorrow then there is a risk since there is a 10% chance of rain, and rain would be undesirable. Furthermore, if this is a business event and $100,000 would be lost if it rains, then the risk has been quantified (a 10% chance of losing $100,000). These situations can be made even more realistic by quantifying light rain vs. heavy rain, the cost of delays vs. outright cancellation, etc (Wikipedia).

https://www.researchgate.net/publication/258835771_Decision_making_under_uncertainty_in_energy_systems_State_of_the_art

Article Decision making under uncertainty in energy systems: State of the art

Dear Alireza,

It's so kind of you for sending this article. I would be more than happy if you could write your opinion directly as well.

Regards,

Since Knight introduced the notion of uncertainty much has happened, and we can not really discuss the distinction between RISK and UNCERTAINTY unless we introduce the intermediate notion of AMBIGUITY.

The example you give (range of volatility of returns) falls clearly in the domain of ambiguity since you have some information. 

Investing in R&D is a good example of uncertainty.

I suppose venture capital could fall under the uncertainty category.

Returns from launching a new product (financial or otherwise) also.

For the example you give an extensive body of literature has been growing under the general term ROBUST OPTIMIZATION. A good part of it is geared towards financial applications. One of the first paper on this broad topic is linked below.

I attach the relevant slides from a course on Enterprise Risk Management I am teaching where I explain precisely these issues.

Article Robust Optimization of Large-Scale Systems

I found an article which has quite interesting view ... please find it attached.