evidence: Global Surface Temperatures Are Rising Faster Now Than At Any Time In The Past 485 Million Years The headline pretty much says it all. A team of climate researchers led by Emily Judd at the University of Arizona and The Smithsonian have combined more than 150,000 pieces of fossil evidence with state of the art climate models to determine the Earth’s average global surface temperatures during the past 480 million years, a timeline that begins with with the emergence of multi-cellular, non-microscopic organisms at the beginning of the time period known as the Phanerozoic Eon. The results show that the Earth has been hotter — much hotter, actually — during most of that time and humans first appeared during one of the coolest periods. It also shows that over the past 480 million years, temperatures have never risen as quickly as they are doing today.