Last week in CNN a piece by Bill McGuire, a professor emeritus of geophysical and climate hazards at University College London, discusses the issue of climate change making this claim....

Think about that for a moment. We’re experiencing, in our lifetimes, a heating episode that is probably unique in the last 4.6 billion years.

Scientifically, it is inaccurate to claim that the current rate of climate change is the most rapid or extreme in the Earth's entire history without specific qualifiers, especially when considering geological epochs that have experienced dramatic shifts due to various natural processes.

Over its 4.6 billion-year history, Earth has undergone numerous and profound climatic shifts. These include ice ages, known as glacial periods, and warmer interglacial periods. The most recent Ice Age ended approximately 11,700 years ago, ushering in the current interglacial period known as the Holocene epoch.