One of the biggest challenges of climate science seems like it should be one of the easiest; measuring temperatures. The fact is, regular measurements of temperature around the globe didn't being in real earnest until the late 19th century. So when scientists what to understand what temperatures were like prior to that era, they have to use proxies. For example, scientists can tell by the way ice crystallizes what the weather and temperature was like thousands of years ago in ice core samples from polar regions. In the modern era, although there have been steady measurements, they've taken ... Read More