Temperature Trends

2014 Hottest Year on Record, Says NOAA: Climate Models Still Wrong on Trend



USA Today is reporting that the National Oceanic and Atmospheric Administration (NOAA) is reporting that 2014 is the hottest year since 1880. From USA Today:

The global temperature from 2014 broke the previous record warmest years of 2005 and 2010 since record-keeping began in 1880.

The average temperature for 2014 was 58.24 degrees globally, 1.24 degrees above the 20th-century average, NOAA said.

USA Today publishes a nice graph from NOAA showing the global sea and land temperature trends. Interestingly, the graph notes that if the temperature trend from 1998 to 2014 were sustained for a century that global average temperature would increase by just over 1 degree Fahrenheit. See below:

NOAA Temperature Trend

So global average temperature is not increasing at the rate of about 0.3 degree Celsius (0.54 degree Fahrenheit) per decade that is the average of the climate models relied upon by the Intergovernmental Panel on Climate Change (IPCC). Regarding the 17 year slow-down in global temperature increases, the IPCC's Synthesis Report just released in November notes:

The observed reduction in surface warming trend over the period 1998 to 2012 as compared to the period 1951 to 2012, is due in roughly equal measure to a reduced trend in radiative forcing and a cooling contribution from natural internal variability, which includes a possible redistribution of heat within the ocean (medium confidence). The rate of warming of the observed global mean surface temperature over the period from 1998 to 2012 is estimated to be around one-third to one-half of the trend over the period from 1951 to 2012. …

For the period from 1998 to 2012, 111 of the 114 available climate-model simulations show a surface warming trend larger than the observations…. The difference between models and observations may also contain contributions from inadequacies in the solar, volcanic, and aerosol forcings used by the models and, in some models, from an overestimate of the response to increasing greenhouse gas and other anthropogenic forcing (the latter dominated by the effects of aerosols).

Shorter: The climate models could be wrong for all sorts of reasons.

Last week, I reported that the satellite data shows that 2014 was the third warmest year in that record. University of Alabama in Huntsville climatologist John Christy noted:

2014 was the third warmest year in the 36-year global satellite temperature record, but by such a small margin (0.01 C) as to be statistically similar to other recent years, 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. "2014 was warm, but not special. The 0.01 C difference between 2014 and 2005, or the 0.02 difference with 2013 are not statistically different from zero. That might not be a very satisfying conclusion, but it is at least accurate."

The 2014 average temperature anomaly also is in keeping with temperatures since late 2001, when the global average temperature rose to a level that is generally warmer than the 30-year baseline average. The most recent 13 complete calendar years, from 2002 through 2014, have averaged 0.18 C (about 0.33 degrees Fahrenheit) warmer than the 30-year baseline average, while the global temperature trend during that span was a warming trend at the rate of +0.05 C per decade — which is also statistically insignificant.

In other words, as hot as 2014 is, there is still no sign of a speed up in the rate of global average temperature increase.