Given the task definition and input, reply with output. In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. There are several possible answers, you'll need to choose the proper one. Carefully read the given text, pay special attention to the marked number, think about what (unwritten) information the marked number holds inside, choose the most adequate word(s) from the optional answers. If none of them seems right to you, there's also an option for other. If your answer is "REFERENCE", also write the reference entity, otherwise write the implicit option name. Options to choose from are:
REFERENCE: Some object which is being mentioned in the text before or after the target number. The reference answer has a higher priority than any other. If both Reference and another answer are possible, prioritize the Reference.
YEAR: Describing a calendric year
AGE: Describing someone's age
CURRENCY: Reference to some monetary value e.g dollar, euro etc.
PEOPLE: Describing a single/plural persons
TIME: Describing a time of the day. Usually you can add the word o'clock after those numbers.
OTHER: Some other option, which isn't listed here.

Himself - President & Co-Founder, The Breakthrough Institute:  We 're basically gon na double the amount of energy we consume by 2050 , we 're gon na triple it or quadruple it by the end of the century .
Himself - President & Co-Founder, The Breakthrough Institute: And meanwhile , if you want to stabilize emissions at some reasonable level , almost all of that energy has to be clean energy .
Himself - President & Co-Founder, The Breakthrough Institute: You 've got to not only create a clean energy infrastructure to replace the fossil - fuel infrastructure we have , but we have to create another _ one _ or maybe two of them between now and 2050 or 2100 in order to reduce our emissions to stabilize the climate .
Himself - President & Co-Founder, The Breakthrough Institute: And that is just nothing that anybody has been talking about or dealing with in the last 20 years .

REFERENCE infrastructure