As the debate rages over global warming, it is important to understand what exactly is being debated. Nearly every scientist will support the fact that in the last 30 – 40 years, the Earth has gotten warmer. What continues to be debated, and rightfully so, is the reason for the warming trend. Are we seeing a natural trend or is the warming something anthropogenic (caused by humans). In the following several posts are shown the primary data points that clearly show that warming is occurring.
Global Surface Temperature
Since about 1950, the Earth’s global surface temperature has risen by just more than .6 degrees Celsius or just over 1 degree Fahrenheit.
Arctic Sea Ice
Using data reported from the National Snow and Ice Data Center, we can track the decline of Arctic sea ice. The image below shows the month of September with the 1978 – 1981 averages on the left, and Arctic sea ice from September 2007 on the right, which produced the smallest area of Arctic sea ice to date. This equates to a decline of nearly 32% in the Arctic sea ice. While the sea ice area has since increased from the record low of 2007, the level remains far below the those recorded since 1979.
The image on the left shows the average ice cover at the end of the summers of 1979 – 1981. The image on the right shows the ice cover at the end of summer in 2007.