There are several data sets that we use to determine US and global temperatures. Some data sets are derived from measurements taken at the surface. Others are taken from satellites which sample the atmosphere from the surface to about 8 kilometers above the surface. These measurements began in the late 1970s.
Anyway you slice it, this year was a very warm year across northern Ohio, the US and globally. December started our very warm but flipped to below normal highs by Christmas. This trend has continued into early January.
The super-warm March really tipped the scales across the US. Satellite data analysis is complete for 2012. The University of Alabama-Huntsville report is as follows. I broke up each sentence to make it easier to digest.
"Globally, 2012 was the ninth warmest year among the past 34, with an annual global average temperature that was about 0.29 degrees Fahrenheit warmer than the 30-year baseline average, according to Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville.”“…2012 was about three one-hundredths of a degree C warmer than 2011, but was 0.23 C cooler than 2010.”“…Eleven of the 12 warmest years in the satellite temperature record have been been since 2001. From 2001 to the present only 2008 was cooler than the long-term norm for the globe.""While 2012 was only the ninth warmest year globally, it was the warmest year on record for both the contiguous 48 U.S. states and for the continental U.S., including Alaska.”“…For the U.S., 2012 started with one of the three warmest Januaries in the 34-year record, saw a record-setting March heat wave, and stayed warm enough for the rest of the year to set a record.“….Compared to seasonal norms, March 2012 was the warmest month on record in the 48 contiguous U.S. states…The annual average temperature over the conterminous 48 states in 2012 was about 0.99 degrees F warmer than seasonal norms."“…From 2001 to the present only 2008 was cooler than the long-term norm for the globe. Despite that string of warmer-than-normal years, there has been no measurable warming trend since about 1998. The long-term warming trend reported in the satellite data is calculated using data beginning on Nov. 16, 1978”
Again, these conclusions are derived from satellite data from University Alabama-Huntsville. Here is the top ten WARMEST YEARS GLOBALLY since 1979? Graph of each year globally follows. Notice the warmer temps since the late 1990s versus the colder temps in the 1980s.
1979 through 2012Warmest to coolest1. 1998 0.4192. 2010 0.3943. 2005 0.2604. 2002 0.2185. 2009 0.2186. 2007 0.2027. 2003 0.1878. 2006 0.1869. 2012 0.16110. 2011 0.130