Those who believe that global climate change is a natural process point to history.
First of all, there was the Ice Age. This was a period of time when a large portion of the Earth was covered with ice. The temperature was incredibly low. The last Ice Age was over 10,000 years ago. About 10,000 years ago it started to warm up and ice started to melt. There are still some glaciers leftover from these times. Scientists have discovered that in the last 130,000 years, there were many climate changes that resulted in ice ages- some believe more than 10!
History shows us examples of very distinct climate changes. For example, the Medieval Warming Period, days of harsh barren land, and the Mini Ice Age filled with ice cold temperatures freezing houses and people happen closer to our times.
Between 800-1300 A.D. the Northern Atlantic Region there was the Medieval Warming Period and the temperature became 1 C or 33.8 F warmer . People experienced global warming even though there was no industry!
An important question arose asking “Why did Earth warm then?” According to many scientists, the earth continues to go through a cycle; warming, then cooling, warming, then cooling. This will continue regardless of industry, cars and pollution.