The behalf that Wiesel accepts the Nobel prize is on literature.
Assuming we're just looking at this phrase, "learn'd" suggests that the astronomer studied to become intelligent in the astronomical field.
Answer:
studies show that solar variability has played a role in past climate changes. For example, a decrease in solar activity is thought to have triggered the Little Ice Age between approximately 1650 and 1850, when Greenland was largely cut off by ice from 1410 to the 1720s and glaciers advanced in the Alps.
Explanation:https://climate.nasa.gov/causes/
