Monthly Archives: December 2015

Preliminary 2015 CFSR Global Temperature Anomalies

Preliminary Climate Forecast System Reanalysis (CFSR) estimates of global surface temperature anomalies from the University of Maine Climate Change Institute (UM-CCI) are now available for 2015 and are described below.  These estimates are based on the U.S. National Center for Environmental Prediction (NCEP) Global Forecast System (GFS) model input prepared routinely four times each day to generate global weather forecasts.

The daily UM-CCI CFSR estimates of global surface temperature anomalies are graphed in Figure 1 and show a sudden upward shift in October that has continued through December.  This jump may possibly be related to the peaking of the El Niño cycle as heat from the tropical Pacific is re-distributed around the globe by weather patterns.  The UM-CCI estimates for November and December are preliminary and the raw output provided by UM-CCI have been adjusted using a linear regression formula based on raw versus final estimates during the period from July through October of 2015.

Daily global temperature anomalies 2015

Figure 1. Preliminary CFSR daily global temperature anomalies for 2015 from the University of Maine Climate Change Institute (UM-CCI).

The monthly UM-CCI CFSR estimates of global temperature anomalies for 2014 through 2015 are graphed in Figure 2 along with similar CFSR estimates provided by WxBell (December is preliminary).  This graph also includes the final monthly estimates through November  from the U.S. National Center for Environment Information (NCEI) and from the University of Alabama at Huntsville (UAH) for comparison.  The NCEI estimates are also for surface temperature anomalies based on land and ocean measurements, while the UAH estimates are for lower troposphere temperature anomalies derived from satellite measurements.

Preliminary monthly global temperature anomalies for 2014 through 2015

Figure 2. Preliminary monthly global temperature anomalies for 2014 through 2015.

The preliminary UM-CCI CFSR 2015 annual estimate of global surface temperature anomaly is 0.278 degrees Celsius (C), referenced to the 1981-2010 climatological period, and compares closely to the 0.272C estimate from WxBell for 2015 through December 30.  The annual UM-CCI CFSR estimates for 1979 through 2015 are graphed in Figure 3 along with the NCEI estimates for 1979 through 2014 (as posted in March 2015).  The NCEI estimate for 2015 will likely be well above 0.4C, since the January through November average is already at 0.44C and will probably increase slightly when December is included.  Consequently, the NCEI estimate for 2015 will likely be the highest global temperature anomaly since 1880, whereas the CFSR global temperature anomaly will only rank 5th highest since 1979.

Preliminary annual global temperature anomalies for 1979 through 2015

Figure 3. Preliminary annual global temperature anomalies for 1979 through 2015.

The preliminary CFSR trend of the monthly global temperature anomaly estimates for the 21st Century so far (since 2001) is graphed in Figure 4.  It still shows a downward trend despite the recent large upward spike in monthly anomalies for October through December of 2015.  The trend is still -0.0011C per month which corresponds to -1.32C per century if maintained for another 85 years.  The recent upward spike decreased the statistical confidence in the trend estimate as indicated by the coefficient of determination (R2) of 0.1454 as compared the R2=0.2335 for the trend 2001 through September 2015 before the spike occurred.

Figure 4. Preliminary trend of GFS based CFSR monthly global temperature anomalies 2001 through 2015

Figure 4. Preliminary trend of GFS based CFSR monthly global temperature anomalies 2001 through 2015.

Considering the many uncertainties involved in trying to estimate global surface temperatures or temperature anomalies and associated trends, the overall confidence in this trend is low.  As I have stated in previous posts, my best guesstimate of the overall uncertainty is about 0.3C to 0.5C for recent annual global temperature anomaly estimates.  However, within the overall uncertainty, there does not appear to be any significant or alarming trend, either up or down that would warrant taking action to try to modify the earth’s climate at this time.  In my view, government mandated efforts to reduce human carbon dioxide emissions are a huge waste of time and expenditure that will not likely have an impact on climate trends.  And unfortunately, these efforts will likely cause much more harm than good for humanity.  Hopefully people and governments will come to their senses before too much unnecessary harm is done.

For for the latest CFSR daily and monthly updates to key figures, see the Daily Updates and Monthly Trends pages accessible from the menu bar at the top of this page.

Happy new year everyone!

UM-CCI data source:  Climate Reanalyzer

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CFSR Global Temperature Trends through November 2015

I have been tracking the University of Maine (UM) Climate Change Institute (CCI) daily and monthly global temperature anomaly estimates based on reanalysis of the Global Forecast System (GFS) initialization data, also know as the Climate Forecast System Reanalysis (CFSR).  Daily estimates through November are plotted in Figure 1 for 2015 so far and in Figure 2 for 2014 through 2015 so far.

Global temperature anomaly estimates 2015

Figure 1. UM CCI CFSR daily global temperature anomaly estimates for 2015 January through November

Global temperature anomaly estimates

Figure 2. UM CCI CFSR daily global temperature anomaly estimates for 2014 through 2015 November

These daily estimates show an overall flat trend through most of 2014 and 2015, with a sharp upward jump in October 2015 that continues high into November 2015.  I suspect this jump is related at least in part to the peaking El Niño in the Pacific as it exerts influence on temperatures around the globe.  These short-term changes are weather and not climate.  It will be interesting to see how much longer this small upward spike lasts.

The UM CCI currently has final CFSR monthly estimates through June 2015 and daily estimates through October 2015.  I compiled the final daily estimates into monthly estimates for July through October 2015 and compiled a preliminary November 2015 estimate from preliminary daily estimates.  All of the UM CCI estimates presented here have been normalized to the most recent standard climatological reference period 1981 through 2010.

Figures 3 and 4 show the monthly global temperature anomaly trends for this century so far, 2001 through November 2015, and for the satellite era at the end of the last century 1979 through 2000 respectively.

Global temperature anomaly trend 2001-2015

Figure 3. UM CCI CFSR monthly global temperature anomaly trend for 2001 through 2015 November

Global temperature anomaly trend 1979-2000

Figure 4. UM CCI CFSR monthly global temperature anomaly trend for 1979 through 2000

The recent spike in global temperature anomaly has not significantly changed the downward slope for the 21st century so far, but has reduced the coefficient of determination, indicating a less certain trend.  The indicated trend of -0.0012 degrees Celsius (C) per month corresponds to a trend of -1.44C per century if it continued through the remainder of this century, which is not likely.  For comparison, the trend for the satellite era at the end of the 20th century, 1979 through 2000, is +0.0007C per month which corresponds to +0.84C per century if sustained.

Another way to view the CFSR estimate period is to break it at the intense 1997-1998 El Niño as shown in Figures 5 and 6.  Figure 5 shows the most recent 1997 through November 2015 portion covering nearly 19 years and including the 1997-1998 El Niño .  Figure 6 shows the previous 18 year period period for 1979 through 1996.

Global temperature anomaly trend 1997-2015

Figure 5. UM CCI CFSR monthly global temperature anomaly trend for 1997 through 2015 November

Global temperature anomaly trend 1979-1996

Figure 6. UM CCI CFSR monthly global temperature anomaly trend for 1979 through 1996

Both of these periods show essentially a flat trend with no overall increase or decrease, but with a higher step offset of about +0.3C for the most recent period.  However, during this entire 37 year period, carbon dioxide (CO2) continued to increase steadily with no indication of a step trend.  This data indicates that the relationship of CO2 to global temperature is not at all direct over this long of a time scale, which casts into serious doubt whether it has any significant effect at all.

For for the latest CFSR daily updates to key figures, see the Daily Updates page accessible from the menu bar at the top of this page.