Given the task definition, example input & output, solve the new input case.
You are given a sentence in Japanese. Your job is to translate the Japanese sentence into English.
Example: 第一にキリバス共和国が彼ら自身の利益になると理解したからです
Output: And it was primarily because Kiribati realized that this was in their own self-interest to do this.
The Japanese sentence is correctly translated into English, because the meaning is preserved.

New input case for you: 科学者たちは最初 100年以内に海から氷がなくなると言っていましたがそれが50年になり
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
And in fact, scientists were originally saying sea ice is going to disappear in the next hundred years, then they said 50 years.