Temperature update for Oct 2023 is 1.1C

A little late but here is my update on the global temperatures for October 2023, The method used is always by spherical triangulation. Temperature fell from the peak in September of 1.49 to 1.29 in October.

Temperatures for November showing a cool area off Chile below a continuing El Nino

These are the monthly temperature trends

Monthly temperatures 2010 – Nov 2023

The annual average temperature for 2023 with just 2 months to go is 1.09C for 2023

Annual temperature trends updated for October 2023 compared to the underlying decadal trends.

I am convinced the decadal trends are calculated on an Icosahedral Grid are the most accurate description of “climate change”.

Posted in AGW, Climate Change | 3 Comments

Direct evidence that CO2 forcing alone determines Global Temperatures

The well known result that CO2 radiative forcing is approximately 5.3 Ln (C/CO) [1] is confirmed here by comparing decadal global temperature anomalies with CO2 concentrations. Positive feedbacks are not needed to explain the observed warming. A value of Transient Climate Response of 1.6C is observed to confirm this. The Moana Loa CO2 measurements when combined with earlier estimates of emissions show that CO2 concentrations have essentially been increasing monotonically since before 1955.  As a result we would expect resultant temperatures to  increase linearly with time [see here], unless there are any positive feedbacks present to increase this rate.

A new method based on a fixed Icosahedral binning  over the surface of the earth allows us  to calculate the decadal averages for each bin and then integrate these to derive the global average temperature for each decade from the 1880s to the 2020s. The big advantage of using decadal temperatures rather than annual temperatures is that natural variability (ENSA, AMO, etc) is simply averaged out.

Figure 1 below shows the result using a 1961-1990 baseline.

The red data-points are the decadal temperatures (left hand scale) while the blue dotted line are the Maona Loa CO2 data combined with NOAA CO2 values before 1955. The data after 2020 extends the linear temperature trend and the exponential CO2 increase to 2050

The linear increase in temperature after 1970 shows that a doubling of CO2 by 2050 if this increasing CO2 emissions trend continues ( blue arrows ) would results in a temperature rise of 1.6C. This is almost identical to the value calculated from directly from radiative forcing from CO2 alone. This proves that proposed feedbacks such as changes in cloud cover or increased water vapour have had no measurable effect so far.

Essentially this implies we have at least 40 years left to develop a reliable low carbon energy source (nuclear).


[1] Myhre et al. New estimates of radiative forcing due to well mixed greenhouse gasses Phys.Rev.Lett., 25, 2715-2718,1998

[2] View the 2000s temperature grid by clicking here 2001-2010 (2000s) Click and spin the globe !

Posted in AGW, Climate Change | 45 Comments

Deducing Climate Sensitivity from Decadal Temperature Data

Note: This post is superseded by the following post !

The transient climate sensitivity (TCR) is the observed average warming of the earth following a doubling of atmospheric CO2 concentration. Effectively this means the observed average temperature when CO2 levels reach 560 PPM. The current average level of CO2 is 415 PPM and we measure the effective temperature of the earth each month relative to a normalised 30 year average. These average temperature anomalies vary from month to month and year to year due to internal effects like El Nino or Volcanoes. This September was the highest recorded temperature anomaly, but this does not mean that temperatures are suddenly accelerating. Instead the trend  regularly varies up or down due to internal cycles like El Nino and volcanic eruptions

The best way to measure the underlying sensitivity of the climate to CO2 therefore is to study long term decadal trends. I do this by using a fixed 3D Icosahedral grid, which has the advantage of both having no geometrical biases, and consistency. The method is described here (3) The decadal average simply integrates all recorded temperature anomalies (1961-1990 baseline) over successive 10 year periods. Hence we get the average global temperature anomaly for the 1960s, 1970s etc. These results are remarkably smooth and integrate over ENSO and other short term affects. Therefore I claim this method isolates the underlying enhanced CO2 greenhouse effect from the noise. Here are the results.

Decadal Global temperatures (Red) compared with Moana Loa CO2 levels (Blue, Left Axis)

Assuming a continued linear response  gives a result of a 2.5C rise in temperatures in 2100 under business as usual. However this is likely an upper limit because if we also consider the full CO2 range by including the NOAA estimates from before the industrial revolution then we see a lower temperature response to increasing CO2 levels. Note that here the CO2 axis scale has been changed slightly.

Adding the early industrial revolution CO2 levels (NOAA) shows a less than linear temperature response to CO2 levels

I conclude that TCR (Climate Sensitivity) is less than or equal to 2.5C. This means that there is no  immediate “Climate Emergency” and we have enough time to solve our future energy needs sensibly.


Posted in AGW, Climate Change, climate science, NOAA | 8 Comments