If you like to look at historical paintings, you may notice that they often provide information about the local weather or climate, especially if they are landscape paintings. Art historians have noticed that portrayals of nature have changed over time in response to the changing climate. For example, a painting of a glacier may reveal how much the shape of it has changed now that the climate is warmer. Historians can use these clues in the paintings to reconstruct aspects of past climate from long before scientific instruments were readily available to measure temperature. You can read more about it here.
