Global Temperature for 2022 was 0.84C

The last month of 2022 saw a slight rise in the monthly mean temperature to 0.79C (baseline 1961-1990) resulting in a final yearly average temperature of 0.84C. Arctic air spilled down to lower latitudes bringing extreme cold to the US, Northern Europe and Russia. La Ninja was also weakening (Figure 2)

Finally 2022 ends up as the 4th equal warmest year hinting perhaps of another pause? However  underlying temperature trends are better be measured by using a  10 year icosahedral binning average and this shows no discrepancy.

Annual temperatures as calculated by spherical triangulation relative to a 1961-1990 baseline. This is also compared to the decadal average temperatures calculated using an icosahedral grid

Fig.2 Temperature (anomaly) distribution from Spherical Triangulation of GHCNV4(Land) and HSST4 (Ocean) data

All results can be downloaded

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2022 temperature is 0.86C including October.

2022 looks set to be the 4th/5th warmest year averaging 0.86C above the 1961-1991 baseline after 10 months. The underlying trend is better represented  by the decadal integration which implies an overall warming of about 1.2C since the “pre-industrial” period.  (Note however that coverage uncertainty increases pre 1960, especially ocean temperatures).

Annual temperatures calculated by spherical triangulation. The Decadal temperatures are calculated independently using a 10 year integration over an icosahedral grid.

La Ninja remains a strong influence.

October 2022 regional temperatures are visualised below.

Regional temperature anomalies. La Nina remains strong.

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Climate Sensitivity to CO2

The decadal trend in global temperatures shows  a clear almost linear increase since the 1970s. We can compare this increase to that of CO2 in the atmosphere.

Comparison of decadal temperature increase with Moana-Loa CO2 measurements.

One sees a nearly proportional agreement between temperature and CO2 after ~1970. However CO2 levels have recently been rising faster than linear as highlighted  by the green arrow. So the question is can we isolate what the climate response is to CO2 and measure the climate sensitivity?

Each decadal temperature measurement has an associated average CO2 value for that decade. Is the global temperature a simple function of CO2 and if so how does that compare to theory ? One problem we have is that the early data from 1850 to 1960 shows a non linear trend. There are two possible reasons for this. Either the effect is real and there was a natural variability before 1960 or instead the early data coverage was not reliable enough to infer trends.

Decadal temperatures from 1850 – 2020

However for arguments sake we will ignore this and assume that the trends are correct. So next we plot the temperature rise versus CO2 levels and compare this to the logarithmic radiative formula I derived earlier here. For each decade I calculate the corresponding average CO2 level . In this way I can then plot temperature versus concurrent CO2  level and compare  this to the logarithmic temperature dependence.

Unfortunately there is still a normalisation problem because global temperatures are always calculated as anomalies relative to some 30 year baseline  period,  (1961 – 1990) in my case. CO2 levels in 1970 were 330ppm so I simply normalise the result to this value. Then we can derive a “rough and ready” climate sensitivity to increasing CO2 levels.

With these assumptions a doubling of CO2 would lead to a 1.7C net increase in global temperatures relative to what appears to have  been a  cooler period in the 19th century.

 

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