Global Warming : [On the nasa.gov web site, dated June 3, 2010]
Global warming is the unusually rapid increase in Earth’s average surface temperature over the past century primarily due to the greenhouse gases released by people burning fossil fuels.Tom Nelson: [So how can the 20th century warming be spun as more rapid than this 18th century warming?]
How Does Today’s Warming Compare to Past Climate Change?
Earth has experienced climate change in the past without help from humanity. But the current climatic warming is occurring much more rapidly than past warming events.
Why Do Scientists Think Current Warming Isn’t Natural?
In Earth’s history before the Industrial Revolution, Earth’s climate changed due to natural causes unrelated to human activity. These natural causes are still in play today, but their influence is too small or they occur too slowly to explain the rapid warming seen in recent decades.
[David Archibald] What is also interesting is the 2.2° temperature rise from 7.8° in 1696 to 10.0° in 1732. This is a 2.2° rise is 36 years [in Central England]. By comparison, the world has seen a 0.6° rise over the 100 years of the 20th century. That temperature rise in the early 18th century was four times as large and three times as fast as the rise in the 20th century.