The least - squares linear - regression trend on the RSS satellite monthly global
mean surface temperature anomaly dataset continues to show no global warming for 18 years 9 months since February 1997, though one - third of all anthropogenic forcings have occurred during the period of the Pause.
We also know that the best definition of the forcing is the change in flux at the tropopause, and that the most predictable diagnostic is the global
mean surface temperature anomaly.
Given that we're mainly looking at the global
mean surface temperature anomaly, the most appropriate comparison is for the net forcings for each scenario.
This can be as simple as assuming an estimate of the global
mean surface temperature anomaly is truly global when it in fact has large gaps in regions that are behaving anomalously.
Given that we're mainly looking at the global
mean surface temperature anomaly, the most appropriate comparison is for the net forcings for each scenario.
Of course I've seen the often used IPCC TAR result here showing that modelling results combining natural and anthropogenic forcings reproduce 20th century global
mean surface temperature anomalies relative to the 1880 to 1920 mean.
Global
mean surface temperature anomalies (°C), relative to the period 1901 to 1950, from observations (black) and simulations (blue)[from Climate Change 2007: Working Group I: The Physical Science Basis]
Note that this result is not directly a test of model fidelity, but rather of linearity; what is converging here is the model's representations of air - sea interaction leading to global
mean surface temperature anomalies, not whether the models have the ability to capture the magnitude or even the spatial patterns of observed RASST variability.
The observed changes (lower panel; Trenberth and Fasullo 2010) show the 12 - month running means of global
mean surface temperature anomalies relative to 1901 — 2000 from NOAA [red (thin) and decadal (thick)-RSB- in °C (scale lower left), CO2 concentrations (green) in ppmv from NOAA (scale right), and global sea level adjusted for isostatic rebound from AVISO (blue, along with linear trend of 3.2 mm / year) relative to 1993, scale at left in mm).
Not exact matches
Firstly, what is the best estimate of the global
mean surface air
temperature anomaly?
First, a graph showing the annual
mean anomalies from the CMIP3 models plotted against the
surface temperature records from the HadCRUT4, NCDC and GISTEMP products (it really doesn't matter which).
Figure 5 - June - August
surface temperature anomalies in 2009 - 2011 in units of °C (a), and in units of the local standard deviation of local seasonal -
mean temperature (b).
December - February
surface temperature anomalies 2009 - 2011 in units of °C (a), and in units of the local standard deviation of local seasonal -
mean temperature (b).
(The specific dataset used as the foundation of the composition was the Combined Land -
Surface Air and Sea -
Surface Water
Temperature Anomalies Zonal annual
means.)
[Response: The global
mean temperature anomaly is the 2D integral of
temperature anomalies over the
surface.
Firstly, what is the best estimate of the global
mean surface air
temperature anomaly?
-- What's the
mean avg growth in global CO2 and CO2e last year and over the prior ~ 5 years — What's the current global
surface temperature anomaly in the last year and in prior ~ 5 years — project that
mean avg growth in CO2 / CO2e ppm increasing at the same rate for another decade, and then to 2050 and to 2075 (or some other set of years)-- then using the best available latest GCM / s (pick and stick) for each year or quarter update and calculate the «likely» global
surface temperature anomaly into the out years — all things being equal and not assuming any «fictional» scenarios in any RCPs or Paris accord of some massive shift in projected FF / Cement use until such times as they are a reality and actually operating and actually seen slowing CO2 ppm growth.
«The average global
temperature anomaly for combined land and ocean
surfaces for July (based on preliminary data) was 1.1 degrees F (0.6 degrees C) above the 1880 - 2004 long - term
mean.
Tropical Atlantic (10 ° N — 20 ° N) sea
surface temperature annual
anomalies (°C) in the region of Atlantic hurricane formation, relative to the 1961 to 1990
mean.
The improved simulation of ENSO amplitude is mainly due to the reasonable representation of the thermocline and thermodynamic feedbacks: On the one hand, the deeper
mean thermocline results in a weakened thermocline response to the zonal wind stress
anomaly, and the looser vertical stratification of
mean temperature leads to a weakened response of anomalous subsurface
temperature to anomalous thermocline depth, both of which cause the reduced thermocline feedback in g2; on the other hand, the alleviated cold bias of
mean sea
surface temperature leads to more reasonable thermodynamic feedback in g2.
Figure 2: Gillett et al. time series of global
mean near -
surface air
temperature anomalies in observations and simulations of CanESM2.
Running twelve - month averages of global -
mean and European -
mean surface air
temperature anomalies relative to 1981 - 2010, based on monthly values from January 1979 to March 2018.
Running twelve - month averages of global -
mean and European -
mean surface air
temperature anomalies relative to 1981 - 2010, based on monthly values from January 1979 to April 2018.
Running twelve - month averages of global -
mean and European -
mean surface air
temperature anomalies relative to 1981 - 2010, based on monthly values from January 1979 to February 2018.
It doesn't
mean the
surface or tropospheric
temperature anomaly must linearly increase from one year to the next, or be larger each five years than the previous five years.
All data are shown as global
mean temperature anomalies relative to the period 1901 to 1950, as observed (black, Hadley Centre / Climatic Research Unit gridded
surface temperature data set (HadCRUT3); Brohan et al., 2006) and, in (a) as obtained from 58 simulations produced by 14 models with both anthropogenic and natural forcings.
What is important is that the vast majority of people are unaware of this issue and the effect these post 1990 station drop outs have on the validity of deriving a so called
mean global
surface temperature (MGST)
anomaly post 1990.
Global
surface and lower troposphere monthly
mean anomalies relative to the 1979 - 1998
mean temperature.
Global
temperatures usually are described in terms of the
surface air
temperature anomaly, the deviation of the
temperature at each site from a
mean of many years that is averaged over the whole world, both land and oceans.
It is officially the
mean sea
surface temperature anomaly from the equator to 70 degrees North.
Image to right — Looking at Average Monthly Global
Temperatures: This is a global map of unusual (anomaly) monthly - mean surface temperatures for the year 2004 relative to the 1951 - 19
Temperatures: This is a global map of unusual (
anomaly) monthly -
mean surface temperatures for the year 2004 relative to the 1951 - 19
temperatures for the year 2004 relative to the 1951 - 1980 baseline.
Jun - Jul - Aug
surface temperature anomalies in 1955, 1965, 1975 and the past nine years relative to 1951 - 1980
mean.
But the «
mean» of kriged, adjusted
anomalies of a small portion of the
surface air (and rarely sea
surface) of the globe are referred to in all the scare propaganda as «Global Average
Temperature.»
Suggested Topic: The recent slowdown in global
mean surface temperature has nevertheless been accompanied by increasingly severe large scale circulation
anomalies.
Figure 12: Annual
mean temperature anomalies (departure from
mean) for Australia (1911 — 2014), using the ACORN - SAT dataset and a range of other local and international land - only (LO) and blended (BL) land / ocean datasets based upon
surface - based instruments.
Significantly, the models appear to be consistent in their predicted global
mean surface temperature response to RASST
anomalies.
The first step requires linking SST
anomalies to
anomalies in the global
mean surface temperature.
These linear discriminants, which consist of an RASST
anomaly field and a time series that describes the projection of that
anomaly in the annual
mean RASST field, maximize the ratio of inter-decadal to inter-annual variability, in keeping with our desire to understand the decadal - to - century scale variability in the global
mean surface temperatures (see SI Text and Figs.
Global
mean surface temperature calculated by applying the weights of Fig. 1B to the linear discriminants that maximize the ratio interdecadal - to - interannual variability in the residual
anomaly SST.
Overall, in the absence of major volcanic eruptions and, assuming no significant future long term changes in solar irradiance, it is likely (> 66 % probability) that the GMST -LCB- global
mean surface temperature -RCB-
anomaly for the period 2016 — 2035, relative to the reference period of 1986 — 2005 will be in the range 0.3 °C — 0.7 °C -LCB- 0.5 °F — 1.3 °F -RCB-(expert assessment, to one significant figure; medium confidence).
We illustrate observed variability of seasonal
mean surface air
temperature emphasizing the distribution of
anomalies in units of the standard deviation, including comparison of the observed distribution of
anomalies with the normal distribution («bell curve») that the lay public may appreciate.
Further to my previous comments, it should be noted that the warm
anomalies («
anomaly»
means the difference from the norm, whether yearly, seasonal, monthly, etc.) mentioned are sea
surface temperatures.
We can not even measure
mean global
surface temperature anomalies to within a factor of 2; and the IPCC's reliance upon
mean global
temperatures, even if they could be correctly evaluated, itself introduces substantial errors in its evaluation of climate sensitivity.
June — July — August
surface temperature anomalies in 1955, 1965, 1975, and the past 6 y relative to the 1951 — 1980
mean.
June — July — August
surface temperature anomalies in 1955, 1965, 1975, and in 2006 — 2011 relative to 1951 — 1980
mean temperature in units of the local detrended 1981 — 2010 standard deviation of
temperature.
To create the CRUTEM
surface temperature analysis, CRU scientists take
temperature data from 4,138 stations, and for each station they calculate the
mean temperature for 1961 - 1990 and
temperature anomalies relative to that period.